Category Archives: Blog

Ultrasonic Flow Detectors

Posted on by

Ultrasonic flow detectors are an important part of ultrasonic flow meters. Ultrasonic flow detectors are also called ultrasonic transducers. Ultrasonic flow detectors measure the volumetric flow of liquid within closed conduits. Ultrasonic flow meters use transit-time differences for measuring flow rates inside pipes from the outside using electronics and digital signal processing technology.

Get a Quote Ultrasonic Flow Meters
Ultrasonic Flow Detectors

Featured Ultrasonic Flow Meters Clamp-on

Portable Ultrasonic Flow Meter
Handheld Ultrasonic Flow Meter
Clamp on Ultrasonic Flow Meter
Ultrasonic Clamp on Flow Meter
Strap on flow meter X3

Features of Ultrasonic Flow Detectors

  • Built-in magnet, which can be directly attached to the pipe;
  • Can be used in strong electromagnetic interference occasions;
  • After the junction box is filled with glue, the protection level is IP68;
  • Complete specifications, divided into three models: large, medium, and small;
  • Measuring pipe diameter range DN15-DN6000;
  • The temperature range is -30~90°℃; -30~160℃
  • The measurement liquid is relatively wide, including water, seawater, slurry or oil, acid and alkali, and other homogeneous liquids;
  • Non-contact measurement method, lightweight and small size;
  • The installation of the clamp-on ultrasonic flowmeter probe is simple. And different sizes of probes can detect pipes of different pipe diameters. Under the condition of ensuring accuracy, the clamp-on ultrasonic flowmeter can measure the smallest pipe of DN15. The largest can measure DN6000 pipeline;
  • The external clamp ultrasonic flowmeter does not need to destroy the pipeline in the process of measuring the flow rate. The probe can directly touch the straight pipe section. No pressure loss. The flow measurement can be performed on the already installed pipe;
  • Suitable for measuring pipes of different materials. Common ones are metal pipes: stainless steel, carbon steel, cast iron, etc., plastic pipes, etc. There are also pipes with better sound-permeable materials.

Optional Ultrasonic Flow Detectors

Types Picture Spec. Model Measurement Range Temperature Dimension
Clamp on
Small Size TS-2 DN15~DN100 -30~90℃ 45×25×32mm
Medium Size TM-1 DN50~DN700 -30~90℃ 64×39×44mm
Large Size TL-1 DN300~DN6000 -30~90℃ 97×54×53mm
High Temperature Clamp on Small Size TS-2-HT DN15~DN100 -30~160℃ 45×25×32mm
Medium Size TM-1-HT DN50~DN700 -30~160℃ 64×39×44mm
Large Size TL-1-HT DN300~DN6000 -30~160℃ 97×54×53mm
Mounting Bracket Clamp on Small Size HS DN15~DN100 -30~90℃ 318×59×85mm
Medium Size HM DN50~DN300 -30~90℃ 568×59×85mm
Extended EB-1 DN300~DN700 -30~90℃ 188×59×49mm
High Temperature Mounting Bracket Clamp on Small Size HS-HT DN15~DN100 -30~160℃ 318×59×110mm
Medium Size HM-HT DN50~DN300 -30~160℃ 568×59×110mm
Extended EB-1-HT DN300~DN700 -30~160℃ 188×59×49mm
MoeldX3-φ6.35X3-φ9.53 X3-φ12.7X3-φ15X3-φ20X3-φ25
Weight(KG)0.910.910.90.90.840.84
MoeldX3-φ32X3-φ40X3-φ50X3-φ63X3-φ75X3-φ99
Weight(KG)0.820.880.981.431.521.95

Ultrasonic Flow Detectors Working Principle

Ultrasonic Flow Detectors are also called ultrasonic transducers. In fact, it is a piezoelectric ceramic whose frequency is the same as its resonant frequency. It uses the piezoelectric effect of the material to convert electrical energy into mechanical vibration.

Under normal circumstances, ultrasonic waves are first generated by an ultrasonic generator. It is converted into mechanical vibration by the ultrasonic transducer. The ultrasonic wave can be generated by the ultrasonic wave deriving device and the ultrasonic wave receiving device.

Ultrasonic transducers mainly include shell, acoustic window (matching layer), piezoelectric ceramic disc transducer, backing, lead-out cable, receiver, and other parts.

Among them, the piezoelectric ceramic disc transducer plays the same role as a general transducer. It is mainly used to transmit and receive ultrasonic waves, and above the piezoelectric ceramic disc transducer is the receiver. It is mainly composed of lead cables, transducers, metal rings, and rubber washers. Used as an ultrasonic receiver. Receive the Doppler dial-back signal generated outside the frequency band of the piezoelectric ceramic disc transducer.

Ultrasonic transducers are piezoelectric ceramics that resonate at ultrasonic frequencies. The piezoelectric effect of the material converts electrical signals into mechanical vibrations. The ultrasonic transducer is an energy conversion device. Its function is to convert the input electric power into mechanical power (ultrasound) and then transmit it out. , It consumes a small part of its own power.

Types of ultrasonic transducers: can be divided into piezoelectric transducers, sandwich transducers, cylindrical transducers, inverted horn transducers, and so on.

Frequently
Asked
Questions

Help Center

Transit Time Ultrasonic Flow Meter adopts the measurement principle of the time difference method. It uses the ultrasonic wave emitted by the sensor to propagate in the flowing fluid. The sound wave propagation speed in the downstream direction will increase, and the backward direction will decrease. In the same propagation distance, there will be different transmission times. According to the difference between the transmission time and the measured The relationship between fluid velocity measures the fluid velocity.

The flow rate of the fluid is different in different positions in the tube. The flow rate in the center of the tube is faster than the flow rate near the wall of the tube. The flow velocity distribution of the fluid in the pipeline can be represented by the flow velocity cross-sectional distribution diagram.

By setting the flowmeter and considering the cross-sectional distribution of the flow velocity, the average flow velocity can be calculated. Then the volume flow of the fluid can be obtained according to the cross-sectional area of the pipe.

Extended reading: Ultrasonic flow detectors types

Notes:
V measure fluid velocity
M ultrasonic reflection times
D pipe diameter
θ The angle between the ultrasonic signal and the fluid
T up The time when the downstream sensor transmits the signal to the upstream
T down Time from upstream sensor to downstream
ΔT = T up – T down

Guess You’ll Like: Ultrasonic flow meters types & technical guide

Doppler ultrasonic flowmeter uses the physical principle of Doppler frequency shift to measuring the water flow velocity. Therefore, the Doppler ultrasonic flowmeter is suitable for measuring fluids containing solid particles or air bubbles. Not suitable for measuring pure water.

The scope of use includes:
Natural rivers, artificial rivers, farmland channels, urban sewers, corporate sewage outlets, sewage treatment plants, etc.

The products comply with the SL/T 186-1997 standard.

It is suitable for environments that require continuous and accurate measurement of flow rate and flow rate. It has obvious advantages such as convenient installation and maintenance, high reliability, and high precision.

Ultrasonic flow detectors are also called ultrasonic transducers. Or it is often understood by people as an ultrasonic flow sensor.

Ultrasonic flowmeter is an application of ultrasonic, which measures the flow of liquid by applying the speed difference method.

  • Can do non-contact measurement;
  • No flow obstruction measurement, no pressure loss;
  • It can measure non-conductive liquids, which is a supplement to the electromagnetic flowmeter for unobstructed measurement;
  • Except for the pipe section type with measurement, there is generally no need for actual flow calibration;
  • In principle, it is not limited by pipe diameter, and its cost is basically independent of pipe diameter.

Related blogs

Low Flow Meters

What is a low flow meter? Low Flow Meters refer to those flow meters that can…

Gas Rotameter Tips

What is Gas Rotameter? Rotameter is also called float flowmeter. It is often called glass tube…

Sino-Inst, Manufacturer for Ultrasonic Flow Meters. It can measure a single sound-conducting liquid medium of DN 25—150mm. It can measure even liquids such as water, seawater, oil, and slurry.

Sino-Inst’s Ultrasonic Flow Meter, made in China, Having good Quality, With better price. Our flow measurement instruments are widely used in China, India, Pakistan, the US, and other countries.

What is a Venturi Tube?

Posted on by

what is a venturi tube?

The Venturi Tube is a tubular device commonly used to measure fluid flow rates. It is based on a physical principle, the Venturi effect. This effect states that as a fluid passes through a narrow section of a pipe, its velocity increases and its pressure decreases. The design of the Venturi Tube takes advantage of this principle, with a gradually narrowing entrance and a subsequently expanding exit. As fluid enters the narrowed portion of the venturi, it accelerates, causing the pressure to decrease. This change in pressure can be measured by pressure measuring points on the pipe wall and calculated to determine the flow rate of the fluid.

Venturi Tube is a common flow measurement tool in industry. It is widely used in the measurement of various fluids because of its simple structure, good stability and high accuracy.

Get a Quote More Flowmeters

Venturi Effect

The Venturi effect describes the increase in velocity and decrease in pressure as a fluid passes through a narrow section of a pipe. When fluid enters a narrow section of a pipe, the flow rate increases and the corresponding pressure decreases. This effect was discovered by Italian physicist Giovanni Battista Venturi, hence its name.

This effect can be explained by Bernoulli’s equation. This equation is a fundamental law of fluid dynamics. Show that in an incompressible fluid without viscosity, the energy of the fluid along the streamline is conserved.

P + 1/2 ρ v^2 + ρ gh = constant

P represents the pressure of the fluid
ρ is the density of the fluid
v is the velocity of the fluid
g is the acceleration due to gravity
h is the height of the fluid

In practical applications, the Venturi effect allows the venturi tube to be used to measure the velocity of a fluid in a pipe, since the velocity of the fluid is proportional to the pressure difference in the pipe.

The Venturi effect is not only used in measurement tools, but is also widely used in many fields such as aircraft wing design, chimney airflow design, and underwater piping systems. It is a very important principle in fluid mechanics and has a profound impact on many branches of engineering and physics.

Venturi tube working principle

The venturi tube is composed of the following parts:

  1. Entrance section: a short cylindrical section with a diameter of D;
  2. Contracting section: the shape is a tapered tube, the cone angle is about 21°±2°;
  3. Throat: a short straight pipe section with a diameter of about 1/3～1/4D and a length equal to the pipe diameter;
  4. Diffusion section: Conical tube with a cone angle of 8°～15°. There is a pressure measuring ring at 0.25-0.75D from the end of the inlet section, with at least 4 pressure measuring holes on it, and the pressure ring leads to the pressure gauge.

In addition, in the center of the throat, there is also a multi-channel pressure measuring ring leading to the pressure gauge. The pressure difference between the inlet section and the smallest section (that is, the throat section) can be measured through the scale of the pressure gauge or the automatic recorder.

Suppose the average velocity, average pressure, and cross-sectional area at the entrance section and the throat are v1, p1, S1, and v2, p2, S2; the fluid density is ρ.

Applying Bernoulli’s theorem and the continuity equation and noting that the streamlines of average motion are of the same height, we can get:

The formula for calculating the flow rate Q can be obtained:

After knowing ρ, S1, S2 and measuring p1-p2, the flow rate Q can be obtained according to the above formula.

The main advantage of the venturi tube is its simplicity of installation. Secondly, due to its diffusion section, the fluid gradually decelerates, reducing the turbulence (see turbulence). Therefore, the pressure head loss is small, no more than 10-20% of the pressure difference between the inlet and the throat.

Venturi tube design

According to the manufacturing process and use, the venturi is divided into standard venturi, general venturi, venturi flow tube, small diameter venturi, rectangular venturi, and other structures. The detailed structure is as follows:

Structure type:

The standard (classic) Venturi tube is composed of an inlet cylindrical section A, a conical contraction section B, a cylindrical throat C, and a conical diffusion section E. The diameter of the cylinder section A is D, and its length is equal to D; the contraction section B is conical and has an included angle of 21º±1º; the throat C is a circular cylinder section with a diameter d, and its length is equal to d; the divergent section E It has a conical shape with a spread angle of 7º～ 15º.

The general-purpose venturi, like the standard venturi, is composed of an inlet cylindrical section A, a conical contraction section B, a cylindrical throat C, and a conical diffusion section E.

The general-purpose venturi adopts the method of changing the contraction angle of the standard venturi and the length of the diffusion section to make it have the advantages of venturi, greatly shortening the length of the body, and effectively reducing the pressure loss.

The Venturi flow tube is also composed of an inlet cylindrical section A, a conical contraction section B, a cylindrical throat C, and a conical diffusion section E. The Venturi flow tube adopts a special pressure method to make it widely used in the flow measurement of dirty media and mixed-phase flow.

The small diameter venturi is composed of an inlet cylindrical section A, a conical contraction section B, a cylindrical throat C, and a conical diffusion section E. The small diameter venturi adopts an integrated mechanical processing method to measure the fluid flow of small diameters. At the same time, it can use a variety of materials to meet the requirements of the on-site working conditions and can meet various connection methods such as welding, flange connection, and threaded connection.

The rectangular venturi is composed of an inlet cylindrical section A, a conical contraction section B, a cylindrical throat C, and a conical diffusion section E. Main technical parameters of rectangular venturi:

  • Nominal diameter: DN=1.13×(WH)0.5≤6000mm
  • Inlet diameter ratio W/H: 0.5≤W/H≤2.0
  • Throat diameter ratio w/h: 0.5≤w/h≤2.0
  • Equivalent β value: 0.44≤β=(w/h)0.5/(W/H)0.5≤0.74
  • Reynolds number range: 2×105≤ReD≤2×107
  • Accuracy: ±1%
  • Repeatability: ±1%
  • Working pressure: 0～25Mpa
  • Working temperature: -100℃～500℃
  • Turndown ratio: 1:10

Rectangular venturi is mainly used in power plant air supply and suction, heating furnace air supply, and suction occasions.

Extended reading: Pitot Tube vs Venturi Meter

How does a Venturi tube measure flow?

Using the Venturi Effect to measure flow, the simple steps are as follows:

  • Install the venturi: First install the venturi in the pipe where the flow is to be measured.
  • Connect the differential pressure sensor:
    • Install a pressure sensor at the wide end and the narrow end of the venturi tube. These sensors measure the pressure difference between the two ends, which is directly related to the fluid velocity.
  • Reading the pressure difference:
    • As fluid passes through a venturi, its velocity increases in the narrow section, causing the pressure there to drop. The differential pressure sensor reads the pressure values at the wide end and narrow end and calculates the pressure difference between the two.
  • Calculate flow velocity:
    • Use Bernoulli’s equation and continuity equation to calculate the velocity of the fluid. v = sqrt(2(P1 – P2)/ρ). where P1 is the pressure at the wide end, P2 is the pressure at the narrow end, and ρ is the density of the fluid.
  • Determine the flow rate:
    • Calculate the flow rate (Q), the formula is: Q = A2 × v. where A2 is the cross-sectional area of the narrow portion of the venturi tube and v is the fluid velocity calculated in the previous step.
  • Recording and monitoring: Continuously monitor pressure difference and flow, and record data for analysis or monitoring system status.

Venturi tube flow meter

Venturi Flow Meter

A Venturi flow meter is a differential pressure flowmeter. The Venturi flow meter is a combination of a Venturi tube, a differential pressure transmitter, and a valve block. It is often used to measure the flow of pressure pipes.

Venturi flow meters are often used to measure the flow of fluids such as air, natural gas, coal gas, and water. It includes three parts: “constriction”, “throat” and “diffusion”. Install on the pipe where the flow rate needs to be measured.

Venturi flowmeter is a new generation of differential pressure flow measuring instruments. The basic measurement principle is a flow measurement method based on the law of conservation of energy-Berlier equation and flows continuity equation.

The throttling process of fluid flowing through the inner venturi tube is basically similar to the throttling process of fluid flowing through a classic venturi tube and an annular orifice plate.

Extended reading: Fluid flow meter types

Venturi flow meters types:

Classic Venturi:

It is applied to the flow measurement of various media and has the characteristics of small permanent pressure loss, the required long and short front and rear straight pipe sections, and long service life.

Casing type venturi:

It is mainly used in the flow measurement and control of various large-caliber and high-pressure or dangerous media in the petrochemical industry.

Venturi nozzle:

It is suitable for the measurement occasions of various media. It has the characteristics of small permanent pressure loss, a short length of the front and rear straight pipes required, and long life. The installation length of the body is shorter than that of the classic venturi.

Extended reading​: What is a flow nozzle?

If it can be accurately manufactured in accordance with ASME standards, the measurement accuracy can also reach 0.5%. However, the accuracy of the domestic Venturi flowmeter is difficult to guarantee due to its manufacturing technical problems.

For the working condition of ultra-supercritical power generation, the use of the equalizing ring at the throat is a very dangerous link under high temperature and high pressure. If the equalizing ring is not used, the standard will not be met. The measurement accuracy cannot be guaranteed. This is a contradiction in the manufacture of high-pressure classic Venturi flowmeters.

The pipe is made of the same material as the inlet and outlet. Fluid scouring and abrasion of the throat are severe. Long-term measurement accuracy cannot be guaranteed. The length of the structure must be manufactured according to regulations. Otherwise, the required accuracy will not be achieved.

Due to the strict structural regulations of the classic venturi, its flow measurement range is the largest and the minimum flow ratio is very small, generally between 3 and 5.

This makes it difficult for Venturi flowmeters to meet flow measurements with large flow changes.

Read more about: 5 Factors Affecting Pressure Drop

Venturi tube application

Since its development, venturi products have been successfully applied to the measurement of high-humidity natural gas, low-pressure dirty biogas, coke oven gas, gas, steam, hot water, high-temperature hot kerosene, etc., And the practical application range is rapidly expanding.

Besides, the venturi tube has a unique measurement advantage, for measuring conditions such as long straight pipe installation conditions, special high temperature, high pressure, strong corrosive and dirty media, and non-single phase flow measurement.

Of course, in the sewage and wastewater treatment industry, in addition to venturi flowmeters, electromagnetic flowmeters are also the first consideration for many users.
For example, if you need to measure the flow of wastewater in a 2-inch pipe. Then you can refer to Magnetic Flow Meters Guides.

Extended reading: Hot Water Flow Meters Improve Heating-Boiler System

Related blog

Flow Transmitter vs Flow Meter

You may have heard of flow transmitters and flow meters. Are flow transmitter and flow meter the same? What is the difference and relationship between them before? Should you buy a flow meter or a flow transmitter? What kind of … Continue reading →

Low Flow Meters

What is a low flow meter? Low Flow Meters refer to those flow meters that can be used to measure micro-flow-low-flow rate media. Including metal rotor type, gear type, electromagnetic type microflow meter, microturbine type, and thermal type small mass … Continue reading →

Gas Rotameter Tips

What is Gas Rotameter? Rotameter is also called float flowmeter. It is often called glass tube float flowmeter, glass rotameter, metal rotameter, and metal tube float flowmeter.Rotameter is mainly used to measure the flow of single-phase non-pulsating fluid (gas or … Continue reading →

Float Flow Meter Technology

What is a float flow meter? The float flow meter is also called a rotameter. The float flow meter is a volumetric flow meter in which a float rises and falls in a vertical tapered tube as the flow changes, … Continue reading →

Solid Flow Meter

What Is a Solid Flow Meter? The solid flow meter is suitable for the measurement of solid mass flow in a wide range of metal-enclosed pipelines from kg/h to t/h. The system is suitable for online monitoring of the flow … Continue reading →

Related DP flowmeters

Orifice Plate Flow Meter
Welding Orifice Plate
 Annubar Flow Meter
Target Flow Meter
Flow Nozzle
Rotameter flow meter-Variable Area

Sino-Inst offers over 50 flow meter products. About 50% of these are differential pressure flow meters (like the Orifice flowmeter), 40% are Magnetic Flow Meters, and 40% are Thermal mass flowmeters.

A wide variety of Annubar flow meter options are available to you, such as free samples, paid samples. 

Sino-Inst is a globally recognized supplier and manufacturer of flow measurement instrumentation, located in China.

The top supplying country is China (Mainland), which supply 100% of the turbine flow meter respectively. Sino-Inst sells through a mature distribution network that reaches all 50 states and 30 countries worldwide.

You can ensure product safety by selecting from certified suppliers, with ISO9001, ISO14001 certification.

Request a Quote

Please enable JavaScript in your browser to submit the form

Flow Transmitter vs Flow Meter

Posted on by

You may have heard of flow transmitters and flow meters. Are flow transmitter and flow meter the same? What is the difference and relationship between them before? Should you buy a flow meter or a flow transmitter? What kind of one to buy?

Let us discuss both flow meter and flow transmitters individually to you understand their concepts thoroughly.

Get a Quote More Flow Meters

What is a Flow Meter?

A flow meter is an instrument used to measure the flow of fluid in a pipeline or open channel. It measures the flow of fluids, liquids, or gases through a closed transmission system.

Flow meters are divided into differential pressure flow meters, rotor flow meters, throttling flow meters, slit flow meters, volumetric flow meters, electromagnetic flow meters, and ultrasonic flow meters. Classified by medium: liquid flow meter and gas flow meter.

Extended reading: Ultrasonic Flow Meters Types & Technical Guide

These different flow meters have different functional principles. For example, an orifice flowmeter calculates the fluid flow at the entrance cross-section of a narrow, restricted opening (called an orifice) and the exit cross-section of the orifice. On the other hand, a rotameter-type flow meter can measure the volume flow inside multiple tubes placed in different areas of the transfer tube.

The above is a general introduction to the flowmeter. simply put. We can think that the flow meter is composed of two parts: the sensor and the signal processor. This structure can be installed separately or as a whole.
So, the signal processing part here is the Flow Transmitter we are going to talk about next.

Extended reading: How does a rotameter work

What is a Flow Transmitter?

The flow transmitter is an important part of the flowmeter. It is a flow meter with an integrated circuit as its operating system. In the flow transmitter, the flow measurement activity is executed by the electronic circuit after receiving the command from the operator. Since flow transmitters have electronic circuits, these devices can be used to control and monitor fluid flow.

Read more about: Flow Meters With GPM Units

For example, the following picture group is the flow transmitter of our common electromagnetic flowmeter.

Guess you like: What is Reynolds number?

Working Principle of Flow Transmitters

A transmitter (transmitter) is a converter that converts the output signal of the sensor into a signal that can be recognized by the controller. It can also convert the non-electricity input from the sensor into an electrical signal and amplify the signal source for remote measurement and control.

There are many types of transmitters. The transmitters used in industrial control instruments mainly include temperature transmitters, pressure transmitters, flow transmitters, current transmitters, voltage transmitters, and so on. Among various types of instruments, transmitters have the most extensive and common applications.

Therefore, the flow transmitter converts the flow signal collected from the flow sensor into an electrical signal. The various electrical signals that have been converted are used to facilitate the reception and transmission of other instruments or control devices. Through the electronic circuit again. Unify the electrical signals from the sensors. Converted to standard 4-20MA.

For example:
The mass flow meter directly measures the mass value. The flow transmitter displays the volume value. This is the biggest difference! The output of the flow transmitter is 4~20MA, and the pressure can be directly displayed by connecting to the secondary meter.

Read more about What is a Flow Transmitter? on Instrumentation Forum.

Extended reading: rotameter applications

Differences between the Flow Meter and Flow Transmitter

The following are some important differences between flow transmitters and flow meters.

  • The flow meter is designed to measure flow. On the other hand, flow transmitters can not only measure flow. They can also help control and monitor flow.
  • The flow meter is a standard mechanical system, such as an orifice plate, pressure gauge, etc. On the other hand, the flow transmitter has a mechanical body and an electronic function circuit.
  • The flow meter is designed for manual field applications. However, the flow transmitter can be operated remotely.

Extended Reading: Magnetic Battery Operated Flow Meter

Flow transmitter types

In fact, there is no strict classification of flow transmitters. The flow transmitter can be configured according to the customer’s functional requirements.
For example, customers need a digital display, 4-20mA output, integrated.
Or, the customer needs battery power. Digital display. No signal output.

Extended reading: Gas Rotameter Tips

Extended Reading: What Is Metal Tube Flow Meter? Rotameter Manufacturer

Flow transmitter calculation

The calibration methods and calibration requirements of flow transmitters with different functions are different. It is recommended that you check with the manufacturer before calibrating the flow transmitter. For example, the flow transmitter supplied by Sino-Inst has a key calibration function. Simple and easy to operate.

For another example, there are two calibration methods for common electromagnetic flowmeters. You may be reading: Magnetic flow meter calibration

Magnetic Open Channel Flow Meter
Magnetic High Pressure Flow Meter
Handheld Ultrasonic Flow Meter
Clamp on Ultrasonic Flow Meter
Ultrasonic Clamp on Flow Meter
Strap on flow meter X3

Extended reading: Make Ultrasonic Open Channel Flow Meter Work for You

Applications of Flow Transmitters

Flow transmitters are commonly used in various industries, including but not limited to:

  • Food & Beverage
  • Industrial production process
  • Environmental protection project: Water and wastewater
  • Pulp & paper
  • Pharmaceutical
  • Biotechnology
  • Oil & Gas
  • Energy metering
  • Metals and Mining
  • Marine
  • Power & Utilities
  • Transportation
  • Chemical
  • Textile
  • Building Automation
  • Micro Electronics
  • Biotechnology
  • Marine meteorology, rivers and lakes

Extended reading: Food grade flow meters for Food & Beverage industry

Extended reading: High Pressure Rotameter for Liquids/gas-Upto 25 Mpa

Related blogs

Low Flow Meters

What is a low flow meter? Low Flow Meters refer to those flow meters that can be used…

Gas Rotameter Tips

What is Gas Rotameter? Rotameter is also called float flowmeter. It is often called glass tube float flowmeter,…

Solid Flow Meter

What Is a Solid Flow Meter? The solid flow meter is suitable for the measurement of solid mass…

Sino-Inst offers over 50 Flow Transmitters, with the Best Price.

A wide variety of Flow Transmitters options are available to you, such as free samples, paid samples.

About 13% of these are magnetic flow meters, 14% are Insertion Magnetic Flow Meter, 25% are Venturi flow meters, 13% are ultrasonic flow meters, and others are Liquid Turbine Flow Meters.

Sino-Inst is a Flow Transmitter supplier, located in China. Flow Transmitter s products are most popular in North America, Mid East, and Eastern Europe. The United States, and India, which export 99%, 1%, and 1% of Flow transmitters respectively.

Request a Quote

Please enable JavaScript in your browser to submit the form

Point Level Measurement Sensors

Posted on by

What is Point Level Measurement?

Point Level Measurement refers to the use of a point level sensor to detect the material level in a storage tank or silo. Also called point level Indicators, Controls, and Switches. This type of equipment is used when it is not necessary to measure every possible intermediate level. Just like in the case of continuous level measurement.

The point level sensor measures the preset level of liquid, mud, or solid media. And open or close the electrical contact at the desired set point. In some applications, sensors are also used to trigger pumps, valves, or other controls. To return the media to the preset level. Capacitive, ultrasonic, rotary, and vibrating liquid level switches are suitable for almost all applications from bulk solids to liquids and in between.

Get a Quote More Level Sensors

What is a point level sensor?

Liquid level measurement usually has two forms: continuous liquid level detection and point liquid level detection. In continuous level detection, the sensor continuously measures the level of liquid or solid in the tank. The point level sensor measures the preset level of liquid, mud or solid media, and opens or closes the electrical contact at the desired set point.

Point level sensor is also called liquid level switch, or liquid level controller. Point level sensor is used for point level detection. The sensor will detect the liquid at a certain point in the tank or chamber. Generally, this applies to processes that need to be managed at a high or low level.

Point level sensor is suitable for liquid, paste, powder, or bulk solid in a silo. You may encounter problems with property changes, turbulence, foam, vibration, or accumulation, but a wide range of sizes, installations and materials make inspection easy.

Common point level sensors, such as photoelectric level switch (SST sensor), horizontal float switch, vertical float switch, ultrasonic level sensor, tuning fork level switch.

Extended reading: Radar level sensor for solids – Dust solid level measurement

What is a continuous level sensor?

The continuous level sensor is designed to provide level detection through every point in the tank or chamber. This means that regardless of the liquid level, it can provide feedback across the entire range of the container. This is very useful for processes where knowing the level is always important and for applications that require increased accuracy.

Common continuous level sensors, such as submersible level sensors, ultrasonic level sensors, capacitive level sensors.

  • Media type (e.g. bulk, powder, liquid, paste, etc.)
  • Media properties (e.g. bulk density, conductivity, viscosity, etc.)
  • Input conditions (e.g. tank material, tank geometry, installation position, installations within the tank, etc.)
  • Process conditions (e.g. pressure, temperature, ambient conditions, explosion protection, hygiene requirements, etc.)

Extended reading: Applicaitons Of Magnetostrictive Level Transmitters

Point level sensor

A sensor designed for point detection will detect liquid at a certain point in the tank or chamber. Generally, this applies to processes that require high-level or low-level management.

In most cases, they act as switches when the tank level rises or falls to a certain level. This could be an alarm or a bonding device. Essentially, the sensor detects when the liquid has reached the desired point, and it acts as a switch to activate the necessary response.

Read more about: Application 3: Level Measurement In Waste Water Treatment Plants

Continuous level sensor

The continuous level sensor is designed to detect the level through every point in the tank or chamber. This means that it provides feedback regardless of the level and the entire container range. This is great for processes where the level is always important, and for applications that require increased accuracy.

Extended reading: Radar Oil Tank Level Sensor

Looking for a specific type or a custom continuous liquid level sensor? Sino-Inst offers High-quality Liquid level sensors for continuous level measurement.

Level sensors are used in process control in many industries and they fall into two categories. Continuous level measurement sensors and Point level measurement sensors. The point level measurement sensor is used to indicate a single discrete level, that is, to indicate a preset level.

The function of this type of sensor is the upper limit alarm, which indicates the overfill condition, or the lower limit alarm condition. Continuous level sensors are more complex, allowing level monitoring of the entire system. They measure the level of the liquid level in a range, not the level of a point. Continuous level sensors produce an analog output that is directly related to the liquid level in the container. To build a level measurement system, this output signal is transmitted to the process control loop and visual indicators.

Read More: Continuous Liquid Level Measurement

Types of Point level measurement

Liquid level measurement is a key link to realize the automated production of industrial processes. According to the difference of its output, it can be divided into Point level measurement and continuous quantity measurement. A wide variety of liquid level switches have caused many obstacles to the correct selection of users. For this reason, the common classifications of liquid level switches are introduced as follows. Hope to be helpful to instrument users.

Extended Reading: What is level transmitter working principle?

After the probe of the capacitive liquid level switch is exposed to liquid, it detects the change of the capacitance value and outputs the contact signal. Generally speaking, capacitive liquid level switches have certain advantages in the measurement of slightly viscous media.

Extended reading: Capacitance level sensor advantages and disadvantages

The electrode type liquid level switch mainly uses the conductivity of the liquid to detect the height of the liquid level. Once the measured medium touches the pole, it will conduct electricity and detect the signal. After the signal is amplified by the controller, it will output a contact signal to realize the control of the liquid level.

The magnetic float of the float level switch rises or falls with the liquid level so that the sensor detects the reed switch chip at the set position in the tube. It sends out contact on/off switch signal. Due to the simple structure of the float level switch, it is economical and practical. It is widely used in the civilian market. But compared with industrial-grade products, its stability is relatively poor.

Extended reading: Oil-water interface measurement-Magtech magnetic level indicator

The photoelectric liquid level switch mainly uses the principle of light refraction and reflection. It is detected by infrared rays. Because the light will reflect or refract at the interface of two different media. When the measured liquid is at a high level, the measured liquid and the photoelectric switch A kind of interface is formed. When the measured liquid is at a low position, the air and the photoelectric switch from another interface. These two interfaces make the reflected light intensity received by the light-receiving crystal inside the photoelectric switch different. That is to say, there are two corresponding interfaces. Different switch states. Generally speaking, the applicability of photoelectric switches is poor compared with other measuring instruments.

Extended reading: Non contact level measurement

HS-ULC Ultrasonic Level Switch-External Mounted

The instrument probe of the ultrasonic external liquid level switch emits ultrasonic waves and detects its after-vibration signal in the container wall. When the liquid flows over the probe, the amplitude of the after-vibration signal will become smaller. The instrument will output a signal after detecting the change Switch signal. Because the ultrasonic external liquid level switch is a non-contact measuring instrument, it is mostly used in the scene where it is not easy to open holes and high risk. But relatively speaking, its cost is relatively high.

Extended reading: The Secret of Ultrasonic Level Measurement

The tuning fork liquid level switch mainly outputs a switch signal by detecting the changes in the frequency and amplitude of the fork vibration. Its versatility is strong, but it is necessary to consult the manufacturer for working conditions with high viscosity. For working conditions that are easy to crystallize, it is not recommended.

Extended reading: ​Solid flow meter | For bulk solids-powder-soybean-cement 

Featured Level switches for point level measurement

ULT-100A Ultrasonic Level Transducer
ULT-200 Ultrasonic Level Detector
Portable Ultrasonic Liquid Level Indicator
HS-2000 Ultrasonic Tank Level Sensor-External Mounted
HS-ULC Ultrasonic Level Switch-External Mounted
HS-ULC-Pro Ultrasonic Non-contact Liquid Level Controller
Ultrasonic Oil Level Sensor-External Paste-Truck Fuel Tank
RF Admittance Level Sensor

SI-LT Magnetostrictive level transmitter with Local Digital Display
SI-80 Radar Level Sensors

SI-U02 Multi-Point Liquid Level Float Switch

SI-U01 Float Level Sensor

Extended reading: Ultrasonic Oil Level Sensor-External Paste-Truck Fuel Tank

Sino-Inst offers over 10 Point Level Measurement Sensors. About 50% of these are liquid level meters, 40% is the tank level sensor.

A wide variety of Point Level Measurement Sensors options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of Point Level Measurement Sensors instrumentation, located in China.

Request a Quote

Please enable JavaScript in your browser to submit the form

What does intrinsically safe mean?

Posted on by

Intrinsically safe type is an explosion-proof type of electrical equipment. When purchasing electrical equipment, do you often hear about intrinsic safety? For example, when ordering pressure transmitters or flow meters.

Intrinsically safe instruments are intrinsically safe instruments. Also called safety spark type instrument. It means that the instrument is in the normal state and in the fault state. The sparks generated by the circuit and the system and the temperature reached will not ignite the explosive mixture.

Get a Quote

What is intrinsically safe?

Intrinsically safe type is an explosion-proof type of electrical equipment. It limits the electric spark or thermal effect energy that may be generated by the inside of the equipment and the connecting wires exposed to the potentially explosive environment to a level that cannot produce ignition.

ia or ib or ic. ia is the highest and ic is the lowest. See GB3836.4-2010 for details.

By controlling the energy level of the equipment itself, it is lower than the critical condition for igniting explosive gas under normal working or fault conditions. It will not produce sparks or higher than the temperature of igniting explosive gas. It does not need to be shielded or blocked by other means.

By limiting the various parameters of the electrical equipment circuit, or taking protective measures to limit the spark discharge energy and thermal energy of the circuit, so that the electric spark and thermal effects generated under normal operation and specified fault conditions cannot ignite the explosive mixture in the surrounding environment. In this way, electrical explosion-proof is realized. The circuit of this kind of electrical equipment itself has explosion-proof performance. That is to say, it is “essentially” safe. So it is called intrinsically safe. Electrical equipment using intrinsically safe circuits is called intrinsically safe electrical equipment.

Because the circuit of intrinsically safe electrical equipment is inherently safe. The sparks, arcs, and heat generated will not ignite the explosive mixture in the surrounding environment. Therefore, intrinsically safe electrical equipment does not require special explosion-proof enclosures. This can reduce the size of the equipment. Volume and weight. Simplify the structure of the device.

At the same time, the transmission line of intrinsically safe electrical equipment can use glue lines and bare wires. It can save a lot of cables.

Therefore, intrinsically safe electrical equipment has the characteristics of safety and reliability, simple structure, small size, lightweight, low cost, convenient manufacturing, and maintenance, etc. It is an ideal explosion-proof electrical equipment.

However, since the maximum output power of intrinsically safe electrical equipment is about 25W, the range of use is limited.

Intrinsically safe electrical equipment is mainly used in communication, monitoring, signal, and control systems, as well as instruments and meters.

Extended reading: How To Install The Pressure Sensor When Measuring The Flow Pipeline?

What are the specifications and guidelines for intrinsic safety?

ATEX (Europe)

The European Union Directive 94/9/EC often referred to as ATEX (“Atmospheric Explosion”). It is the main European regulation for protection systems and equipment used in potentially explosive atmospheres.

The purpose is to serve as a unified directive to lay the foundation for the necessary health and safety requirements. Replace existing different national and European legislation.

The directive is mandatory for electrical and electronic equipment sold in Europe on July 1, 2003 and used in environments affected by explosion hazards.

The ATEX directive has now been adopted all over the world.

NEC (United States)

The National Electrical Code (NEC) is the basis for all electrical codes in the United States. NEC 500 and 505 cover the classification of hazardous areas and related product identification.
NEC 500 explained that it is a long-term regulation. It has been adopted all over the world, except in Europe. NEC 505 is similar to ATEX.

Intrinsically safe symbol

After evaluation, each approved intrinsic safety device should meet ATEX and NEC or Factory Manual standards. Through the corresponding grade system, you can know which areas, protection types, gas groups, and temperature grades the instrument has been approved for.

Example: Fluke 707ex conforms to ATEX II 2 G Ex ia IIC T4

–The ATEX examination mark. This sign is required on all devices for use in European hazardous areas.
II 2 GRegional classification. “II” indicates that the tool has been approved for use in all non-mining areas. “2” indicates the category of the device. In this example, the device is evaluated for use in a ** category* hazardous area. “G” designates the environment, in this case, gas, steam, and moist environment.
ExExplosion protection is based on European Ex regulations.
iaExplosion protection type, in this case, the energy in the device or connector has been reduced to a safe value.
IICGas group. The “IIC” grade indicates the suitability of the * hazardous gas group.
T4The temperature category is the maximum temperature that may exist on the surface.
–Example of Factory Mutual classification: Fluke 707ex is N.I.Class 1, Div 2, Groups A-D, T4 classified by FM.
–The Factory Mutual approval mark.
N.I.A non-flammable instrument with limited internal energy, so it will not ignite the specified environment during use.
Class ICan be used with gas, steam, and liquid (except for dust, fiber, or filing).
Div 2It is certified to be used in “Area 2”, and the explosive gas environment that does not usually exist may exist for a short time in rare cases.
Groups A-DAfter evaluation, it can be used with explosive gases defined in Group A-D. These gases include acetylene, hydrogen, acetylene, and propane.

Read more about: What Is the Difference Between Class 1 Div 1 and Class 1 Div 2 ?

Definitions of Hazardous Areas

According to the frequency and duration of the explosive environment, the hazardous area is divided into different areas.
The gas field is divided into three areas: Zone 0, Zone 1, and Zone 2.

Zone 0Places where the explosive mixture in an explosive environment continuously appears in the form of gas, vapor, or mist or exists for a long time.
Zone 1During normal operation, a place where an explosive mixture in the form of gas, vapor, or mist may occur in an explosive environment.
Zone 1 is a typical application place for explosion-proof electrical equipment.
Zone 2During normal operation, it is unlikely that explosive mixtures in the form of gas, vapor, or mist will appear in an explosive environment, and if they occur, they will only occur occasionally and exist for a short time. Normally, “short time” means that the duration is not more than 2 hours.

The dust site is divided into three areas: Zone 20, Zone 21, and Zone 22:

Zone 20During normal operation, combustible dust appears continuously or frequently, and its quantity is sufficient to form a mixture of combustible dust and air and/or may form an uncontrollable and extremely thick dust layer and inside the container.
Zone 21During normal operation, there may be places where the amount of dust is sufficient to form a mixture of combustible dust and air but is not classified into Zone 20. This area includes places that are directly adjacent to filled or discharged dust, where dust layers appear and places where flammable concentrations of combustible dust and air mixture may be produced under normal operating conditions.
Zone 22Under abnormal conditions, places where combustible dust clouds occasionally appear and only exist for a short period of time, or combustible dust occasionally accumulates or there may be a dust layer and generate combustible dust-air mixtures but are not classified into Zone 21. If it cannot be guaranteed to exclude combustible dust accumulation or dust layer, it should be divided into 21 zones.

Intrinsically safe certification

Intrinsically safe explosion-proof certification technology is currently standardized and suitable for zone 0 technology. For automation instruments, the most commonly used explosion-proof types are intrinsically safe, explosion-proof, and increased safety.

However, due to the rapid development of electronic technology and the continuous birth of low-power electronic devices. So that the promotion and application of intrinsically safe explosion-proof technology has a broader space. Especially because the intrinsically safe explosion-proof type is compared with other explosion-proof types. It not only has a simple structure but also has a wide range of applications. It also has the characteristics of easy operation and convenient maintenance. Therefore, this kind of intrinsically safe explosion-proof, which suppresses the ignition source energy as an explosion-proof method, has been accepted by instrument manufacturers and users.

  1. Basic principles of intrinsically safe explosion-proof certification technology

Electric sparks and thermal effects are the main sources of ignition that cause explosive hazardous gas explosions. Intrinsic safety is achieved by limiting the energy of two possible ignition sources: electric spark and thermal effects.

Under normal working and fault conditions, when the energy of the electric spark or thermal effect that the meter may produce is less than this energy. It is impossible for the instrument to ignite explosive dangerous gas and cause an explosion.

The principle is to start with limiting energy. Reliably limit the voltage and current in the circuit to an allowable range. In order to ensure that the electric spark and thermal effects generated by the instrument in normal operation or short-circuit and component damage, etc., will not cause the explosion of dangerous gases that may exist around it.

  1. Features of intrinsically safe explosion-proof certification technology

Intrinsically safe explosion-proof technology is actually a low-power design technology. Usually, for hydrogen (IIC) environment, the circuit power must be limited to about 1.3w.

It can be seen that intrinsically safe technology can be well applied to industrial automation instruments.

Compared with any other explosion-proof type. The use of intrinsically safe explosion-proof technology can bring the following technical and commercial features to industrial automation instruments:

  • No complicated design and manufacturing process is required. A bulky and heavy flameproof enclosure. Therefore, the intrinsically safe instrument has the characteristics of simple structure, small size, light weight and low cost. According to data, the cost ratio of establishing an intrinsically safe and flameproof switch transmission circuit is about 1:4.
  • Maintenance, calibration and replacement of some parts of the instrument can be carried out under electrified conditions.
  • High safety and reliability. The intrinsically safe instrument will not reduce the safety and reliability of the instrument due to the loss of the fastening bolts or the corrosion of the casing joint surface, scratches and other man-made reasons
  • Because intrinsically safe explosion-proof technology is a kind of “weak current” technology. Therefore, the use of intrinsically safe instruments can avoid the occurrence of electric shock accidents of on-site engineering and technical personnel.
  • Wide application range. Intrinsically safe technology is the only explosion-proof technology applicable to hazardous locations in Zone 0.
  • For simple devices like thermocouples. No special certification is required to access the intrinsically safe explosion-proof system.

In summary, for automated instruments, intrinsically safe explosion-proof technology is an ideal explosion-proof technology. It will also be widely used in the design of Fieldbus intelligent instruments and their systems.

Intrinsically safe vs explosion-proof

It is often necessary to use explosion-proof instruments in industrial sites. The general industrial explosion-proof instruments are mainly explosion-proof and intrinsically safe. So, how to understand the difference between them?

Read more Intrinsically Safe vs Explosion Proof Pressure Transmitters

Choose the right intrinsically safe device for your application

Explosion Proof Pressure Transmitter

SIEP489 Explosion proof pressure Transmitter is a microprocessor-based high-performance transmitter. SIEP489 has flexible pressure calibration, push button configuration, and programmable using HART® Communication. We also supply industrial pressure sensors, and explosion proof differential pressure transmitter.

All our electronic pressure transducers can be offered with Explosion-proof. Select explosion-proof pressure transmitters with Ex d certification and 4-20mA output signals for installation. These installations require the use of equipment and enclosures designated as containing internal explosives. This prevents ignition of the explosive environment surrounding the equipment ( Specified) Flameproof area.

Absolute Pressure Transmitter
Hydrostatic pressure transmitter
SI-PCM261 Submersible Pressure Transducer
Extended Diaphragm Seal DP Level Transmitter
Differential pressure(DP) level transmitter
Diaphragm Seal Pressure Transmitter

Intrinsically Safe Flow Meter

When do I need to choose an explosion-proof or intrinsically safe flowmeter?

Please remember that when you need to measure the medium is flammable and explosive. Be sure to tell the flowmeter manufacturer. Choose intrinsically safe or explosion-proof flow meters.

For example, to measure diesel oil, turbine flowmeters are used. The explosion-proof model must be selected.
Another example is measuring hydrogen. Use vortex flowmeter. The intrinsically safe model must be selected.

Gear flow meter for Micro flow
Liquid Turbine Flow Meter
Turbine Insertion Flow Meter
Handheld Ultrasonic Flow Meter
Ultrasonic Clamp on Flow Meter
Magnetic Water Flow Meter

Sino-Inst offers a variety of Intrinsically Safe vs Explosion Proof Pressure-Level-Flow Transmitters for industrial pressure measurement. If you have any questions, please contact our sales engineers.

Molasses Flow Meters-High Viscosity Liquids Solution

Posted on by

Molasses flow meters are a type of flow meter used for molasses flow measurement. Molasses are common high viscosity liquids. So Molasses flow meters are flow meters that can be used to measure various high viscosity liquids. Can common electromagnetic flowmeters be used to measure high viscosity liquids? What about the Coriolis mass flow meter?

Perhaps after the introduction of this article, you will understand.

Style More Flowmeters

Viscosity is a value obtained by measuring the inherent frictional force of a fluid.
Viscosity is a physical and chemical property of a substance.
It is defined as a pair of parallel plates with an area of A and a distance of dr. The plates are filled with a certain liquid. Now a thrust force F is applied to the upper plate to generate the force required for a degree of speed change.
Due to the effect of viscosity, the object is subjected to frictional resistance and differential pressure resistance when moving in the fluid, resulting in loss of mechanical energy.
Essentially, the more viscous a liquid is and the more resistant it is to flow, the higher its viscosity.

Due to the viscosity of the liquid, this force layer is transmitted layer by layer. Each layer of liquid also moves accordingly. A velocity gradient du/dr is formed. Called the shear rate, expressed by r’.
F/A is called the shear stress and is represented by τ.
The relationship between shear rate and shear stress is as follows:

(F/A)=η(du/dr),

The proportional coefficient η is defined as the shear viscosity of the liquid.
In addition, extensional viscosity and shear viscosity are usually used more often. Generally speaking, when it is abbreviated as viscosity without distinction, it usually refers to shear viscosity.

Therefore, η=(F/A)/(du/dr)=τ/r′.

Immerse two plates with an area of ​​1 square meter in the liquid, and the distance between the two plates is 1 meter. If a 1N shear stress is applied to a certain board. If the relative speed between the two plates is 1m/s, the viscosity of the liquid is 1Pa·s.

Newtonian fluid:

a fluid that conforms to Newton’s formula. Viscosity is only related to temperature, not to shear rate.

Extended reading: Fluid flow meter types

Non-Newtonian fluid:

does not conform to the Newtonian formula τ/D=f(D). Express the viscosity under a certain (τ/D) with ηa, which is called the apparent viscosity.

Viscosity changes significantly with temperature but usually changes little with pressure.

Liquid viscosity decreases with increasing temperature, while gas viscosity increases with increasing temperature.

For solutions, the relative viscosity μr is often used to indicate the ratio of the solution viscosity μ and the solvent viscosity μ. which is:
The relationship between relative viscosity and concentration C can be expressed as:

μr=1+【μ】C+K′【μ】C+…

In the formula, [μ] is the intrinsic viscosity of the solution.

K’ is the coefficient. [Μ], K’have nothing to do with concentration.

The viscosity of different fluids varies greatly.

At a pressure of 101.325kPa and a temperature of 20°C, the dynamic viscosity and kinematic viscosity of air, water and glycerin are:

Air　μ=17.9×10^-6Pa·s,　v=14.8×10^-6m²/s
Water　μ=1.01×10^-3Pa·s,　v=1.01×10^-6m²/s
Glycerin　μ=1.499Pa·s,　v=1.19×10^-3m²/s

More about Viscosity

You may find examples of high and low viscosity fluids- Honey, syrup, glue

Viscosity-table-of-various-liquids

Dynamic viscosity unit conversion

1 poise (1P)=100 centipoise (100cP)
1 centipoise (1cP) = 1 mPa·s (1mPa·s)
1 mPa·s (1mPa·s)=1000 microPascal·s (1000μPa·s)

Conversion of dynamic viscosity and kinematic viscosity
μ=ν·ρ
Where μ－－- dynamic viscosity of sample (mPa·s)
ν－－- Kinematic viscosity of sample (mm²/s)
ρ－－- The density of the sample at the same temperature as the measured kinematic viscosity (g/cm³)

Extended reading: Liquid mass flow controller for process liquid -Sino-Inst

The so-called high-viscosity liquid means that the liquid is viscous and thick. It is different from general liquids and non-Newtonian fluids (mud, pulp). The activity is slow and it is very difficult to filter with simple methods.

What’s more, the liquid contains some dust in addition to it. It also contains colloidal particles that are not completely dissolved.

For example solutions of rubber, paraffin, cellulose acetate, viscose, polyacrylonitrile, paint and animal glue.

Read more about: Coriolis Mass Flowmeter Working Principle

Properties of molasses

What is molasses:

Molasses is a viscous, dark brown, semi-liquid object. It mainly contains sucrose. The content of pantothenic acid in sucrose is higher, reaching 37mg/kg. In addition, the biotin content is also considerable. It is easy to be mixed into soybean molasses and molasses fermentation liquid.

Molasses characteristics

  1. Molasses is a brownish yellow viscous liquid, with the fragrance of yeast and the sweetness of molasses;
  2. The content of CP is high, 3-6%;
  3. High sugar content, generally 42-50%. Low energy density, good taste. Fast digestion and absorption, and the price is lower than corn (2346, 2.00, 0.09%).
  4. Contain vitamins, minerals, bacterial proteins, nucleic acids, surface active substances and growth-promoting factors (biologically active substances) and other ingredients.
  5. Anti-acid and alkali, anti-oxidation, strong chelating ability to divalent cations. It can form organic chelating trace elements with metal ions. Promote the absorption and utilization of minerals by livestock and poultry.

The above is a detailed introduction to what molasses is.

Choosing right molasses flow meters

For the properties of molasses. There are 4 types of flow meters that can be used as molasses flow meters.

The electromagnetic flowmeter is a flow measuring instrument. In the working conditions that require flow measurement, electromagnetic flowmeters are inseparable.

When measuring the flow of low-viscosity and high-viscosity liquids, many people think of electromagnetic flowmeters. In fact, it is right, although I dare not say that the electromagnetic flowmeter is omnipotent. But almost all conductive liquids can be solved by electromagnetic flowmeters.

For diluted molasses. Good liquidity. It can be measured with an electromagnetic flowmeter.

Extended reading: Sludge flow meter for sewage treatment return activated sludge system

Spur Gear Flowmeter is our brand new product. Measure small flow rates. As low as 0.01L/min.

The gear flow meter is a common positive displacement flow meter. The gear flow sensor has built-in double gears to operate. The volume of the medium is calculated by the volume of the gear. The flow rate of the small fluid medium is measured.


Gear flow meters can be used for resin and glue flow measurement. Flow measurement of hydraulic oil, lubricating oil, and grease. Maltose, syrup. Fuel oil flow measurement. Flow measurement of ink and asphalt. Flow measurement of liquid nitrogen, freezing liquid, and solvent. Edible oil, fish oil, and food filling measurement. Chemical and anti-corrosion requirements fluid measurement. A fluid quantitative control system, etc.

Read more about Gear flow meter for Microflow

If the flow rate of molasses is large, how to measure the flow rate of the liquid with high viscosity?

Oval gear flowmeter is a positive displacement flowmeter, also known as displacement flowmeter. It is a type of flowmeter with high measurement accuracy among flow meters, and it is very good at measuring liquids with high viscosity.

The oval gear flowmeter can measure liquids up to Viscosity: 1000-2000mPa.s.

The measurement of the oval gear flowmeter has nothing to do with the flow state of the fluid. The higher the viscosity of the medium, the smaller the leakage from the gear and the metering gap. Therefore, the higher the viscosity, the more advantageous it is for measurement.
Measurable medium: fuel, diesel, gasoline, heat transfer oil, hydraulic oil, kerosene, tar, petroleum, crude oil, asphalt, resin, and other liquids. Especially suitable for the measurement of high viscosity liquids.

Coriolis mass flowmeter has the characteristics of high measurement accuracy, good stability, and easy operation. It is an ideal instrument for measuring the flow of high-viscosity media such as high temperature, high viscosity, and easy crystallization.

The flow and temperature of the high-viscosity medium form a cascade control system. Install an automatic regulating valve on the inlet pipe to automatically cut off and adjust the size of the oil volume according to the reaction temperature. Ensure a fast response state and reduce pure lag time.

After using the mass flowmeter, the flow of the high-viscosity medium is uniform and stable, which reduces the labor intensity of the operators. The pure lag time is shortened, and the quality of the product is guaranteed. Improved economic efficiency.

Extended reading: U-series Liquid Mass Flow Meter | Liquid-slurry flow measure

Liquid Turbine Flow Meter
Turbine Insertion Flow Meter
Turbine Pulse Flow Mete
Clamp Filling Oval Gear Positive Displacement Flow Meter
LCD display Oval Gear High Viscosity Flow Meter
Oval Gear-Marine Fuel Flow Meter
Helical Gear-PD Flow Meter
Gear flow meter for Microflow
Liquid Roots Meter
U-Series Liquid Mass Flow Meter
Magnetic Water Flow Meter
Handheld Ultrasonic Flow Meter
Ultrasonic Clamp on Flow Meter
Magnetic Stainless Steel Flow Meter
Turbine Sanitary flow meter
Low temperature Turbine Flowmeter-Liquid Nitrogen Flow Meter

Related blogs:

Low Flow Meters

What is a low flow meter? Low Flow Meters refer to those flow meters that…

Grease Flow Meters

What is a Grease Flow Meter? Grease Flow meters are meters dedicated to measuring the…

Solvent flow meters

The solvent flow meter is a flow meter that can measure solvent volume or mass…

Mechanical Flow Meters

Selection Guide What is a mechanical flow meter? Mechanical flow meters are a type of…

Sino-Inst, Manufacturer for Molasses Flow Meters-High Viscosity Liquids Solution

Sino-Inst’s Molasses Flow Meters, made in China, Having good Quality, With better price. Our flow measurement instruments are widely used in China, India, Pakistan, the US, and other countries.

Low Flow Meters

Posted on by

What is a low flow meter?

Low Flow Meters refer to those flow meters that can be used to measure micro-flow-low-flow rate media. Including metal rotor type, gear type, electromagnetic type microflow meter, microturbine type, and thermal type small mass flow meter. It can measure the Low flow rate of a variety of liquids and gases. For example, it needs small volume, high-temperature resistance, low-temperature resistance, or medium viscosity. etc. We all have suitable product recommendations.

Get a Quote More Flowmeters

Sino-Inst specializes in low flow meters for micro to low flow rates. We offer:
Ultrasonic flowmeter can measure low flow rates from 0.1m/s to 5.0m/s.
The gear flowmeter can measure the microflow rate from 0.01 to 0.83.
Coriolis mass flow meters and controllers from 10SCCM~30SLM.
Below, we also introduce a lot of flow meters. based on vortex, electromagnetic, ultrasonic, and positive displacement, etc.

Flow range of flow meters

First, let’s take a look at the low flow rate measurement range of conventional flow meters.

Flow meterMediaDNFlow Range (m³/h)L/min 
Electromagnetic Flowmeterliquid150.19~3.18 3.166~53
Turbine flowmeterliquid40.04~0.250.666~4.166
Vortex FlowmeterGas; liquid153～15;0.3～550~250; 5~83.30
Precession Vortex Gas Flowmetergas151～716.66~116.666
Ultrasonic Flow Metersliquid150~±12m/s–
Differential Pressure Flow MetersLiquid; gas150.8m/s–
Oval gear flowmeterliquid100.03-0.2  0.5~3.33
Gear flow meterliquid20.0006~0.0500.01~0.833
Coriolis Mass FlowmeterLiquid; gas30~96~144 kg/h–
Thermal gas mass flow metergas60.1～120Nm/s–
Metal rotor flowmeterGas; liquid150.07~0.7; 2.5~251.166~ 11.66;41.666 ~416.66

Read more about: The Pros and Cons of Micro Motion Flow Transmitters

Low flow meters for Liquids

Cylinder Gear flow meter for micro flow measurement.
Model Measure Range    L/HMeasure Range L/min
GF020.6-500.01~0.83
GF045-2500.083~4.16
GF0610-5000.167~8.33
GF1050-12000.83~20
GF15200-30003.33~50
GF251000-1200016.67~200
GF322000-2000033.33~333
Strap on flow meter X3

ProductStrap on Flowmeter
ModelX3
Flow range0.1m/s~5.0m/s
Accuracy±2.0%
Repeatability0.80%
Pipe sizeφ6.35~φ90
MoeldX3-φ6.35X3-φ9.53 X3-φ12.7X3-φ15X3-φ20X3-φ25
Weight(KG)0.910.910.90.90.840.84
MoeldX3-φ32X3-φ40X3-φ50X3-φ63X3-φ75X3-φ99
Weight(KG)0.820.880.981.431.521.95

Mini Turbine Flowmeter
Caliber
（mm）		Measuring range
（L/min）		Factor
1.15mm0.035-1.60.5
1.3mm0.01-1.860.6
1.5mm0.045-2.080.67
2.0mm0.085-2.321.02
2.5mm0.12-2.41.44
MaterialShell: brass nickel plated/brass/plastic
Bearing: INO×18/8 (1.4305) stainless steel
Impeller: PVDF (polyvinylidene fluoride)
Magnet: SrFeO ceramic, ultrasonic welding
sealMVQ (silicone rubber “O” ring)
temperature range-10℃~+100℃
Accuracy class±2%
Repeat accuracy±0.20%
Pressure rangeMaximum 2MPa
Installation methodHorizontal installation
Dimensions (L×B×H)40×55×40mm
connectMPM connector
Provide power4.5~24VDC
OutputOpen collector
Maximum (extra) voltage output25VDC
Maximum current output25mA
ThreadG1/8 or G1/4
Threaded microflow target type flowmeter
Pipe diameter:DN6mm—50mm (threaded type)
Accuracy:±0.2/ ±0.5/ ±1.0 (liquid flow meter);
±:		-196°C to +700°C.
pressure:Negative pressure -70Mpa
Measuring range ratio:1:100 times; 1:50 times; 1:30 times; 1:10 times
Flow range:Liquid: DN6 to DN80 starting at 0.1L/h (ultra-small flow);
Gas: DN6 to DN80 starting at 15L/h (ultra-small flow);

Extended Reading: Liquid Turbine Flow Meter

Liquid mass flow controller
Measuring rangeLow range: 10SCCM~30SLM
Medium range: 30SLM~300SLM
Large range: 500SLM~3000SLM
Accuracy (under standard conditions after zero adjustments)±1%F.S
Repeatability±1%F.S
Zero drift & full-scale drift0.02%F.S/C/Atm
Working range/range adjustable ratio2%~100%F.S/50:1
Maximum measurable flow100%F.S (controllable)
Typical response time200 milliseconds (adjustable)
Start-up warm-up time<5 seconds

Extended reading: Micro flow meters for low flow liquids

Low flow meters for Gas

Digital air flow meters
ModelCaliberMechanical interfaceFLow Range: SLPMFLow Range: NCMH
MF57066mm1/4″10
25		0.6
1.5
MF571212mm1/2″20012

Gas mass flow controller
Measuring medium:Various gases (except acetylene gas and mixed gas)
Measuring pipe diameter:DN3, 6, 8, 10
Flow range:30, 60, 80, 100, 300, 600, 800, 1000 sccm;
10, 20, 30, 50, 80, 100 SLPM 
Flow measurement accuracy:±1.5%FS; ±2.5%FS
range of working temperature:-25℃-55℃
Working pressure range:0.3MPa, 0.6MPa, 1.0MPa
Power supply:24VDC±10%;
output signal:4-20mA, RS485 communication;

Read more about: Benefits Of Digital Gas Mass Flow Meters

FAQ

  • Coriolis Meters.
  • DP Meters.
  • Magnetic Meters.
  • Multiphase Meters.
  • Turbine Meters.
  • Ultrasonic Meters.
  • Vortex Meters.

Extended reading: How does a rotameter work

The water flow meter is an instrument specially used to measure the flow of water in pipes. You can get many different types of water flow meters from your facility.

When used in certain applications, each flow meter has its own advantages. For many pipelines and similar systems, the water must be maintained at a specified flow rate to ensure the effective operation of the system.

Read more: Digital Water Flow Meters

Related articles:

Gas Rotameter Tips

What is Gas Rotameter? Rotameter is also called float flowmeter. It is often called…

Micro Flow Meter

Micro Flow Meter is a micro oval gear flow meter. It is a kind…

Metal Tube Rotameter

Metal tube rotameter with transmitter Metal tube rotameter with the transmitter is also called…

Extended reading: Gas Rotameter Tips

Sino-Inst, Manufacturer for Low Flow Meters. For example crude oil flow meter, diesel flow meter, gasoline flow meter.

Sino-Inst’s Low Flow Meters, made in China, Having good Quality, With better price. Our flow measurement instruments are widely used in China, India, Pakistan, the US, and other countries.

What Is Capacitance Liquid Level Sensor & How Dose It Work?

Posted on by

What is a capacitive liquid level sensors?

Capacitive liquid level sensor is an instrument for continuous measurement of liquids and converting it to an electrical signal.

Capacitive liquid level sensors play a pivotal role in obtaining precise, continuous measurements of liquids within containers. Being versatile enough to work seamlessly with fuels, oils, water, and coolant fluids. At its core, this sensor gauges the liquid’s height and transforms that data into an electrical signal. This valuable signal can then interface with various instruments, enabling users to visualize, monitor, record, or manage the liquid’s level.

Get a Quote More Level Sensors

Capacitive liquid level sensor with good structure and installation method can be applied to high temperature, high pressure, strong corrosion, easy to crystallize, anti-clogging, anti-freezing, and solid powder and granular materials.

Sino-Inst’s capacitive liquid level sensor can measure the liquid level of a highly corrosive medium. It measures the liquid level of a high-temperature medium. It measures the liquid level of sealed containers. It has nothing to do with the viscosity, density, and working pressure of the medium.

RF Admittance Level Sensor
Capacitance Level Transmitter

Features of capacitive liquid level sensors

  • The structure is simple, without any movable or elastic components. Therefore, the reliability is extremely high and maintenance is minimal. Under normal circumstances, it is not necessary to carry out regular large, medium and small maintenance.
  • Various signal output. Facilitate the configuration of different systems.
  • Suitable for liquid level measurement of high temperature and high-pressure vessels. And the measured value is not affected by the temperature, specific gravity of the liquid being measured and the shape and pressure of the container.
  • It is especially suitable for the measurement of strong corrosive liquids such as acids and alkalis.
  • Perfect over-current, over-voltage, and power polarity protection.

Extended reading: Radar Non Contact Water Level Sensor

Capacitive liquid level sensors types

Extended Reading: How to Measure Volume of Liquid

How does a capacitive liquid level sensor work?

Define capacitor

What is a Capacitor?

A capacitor is a passive electronic component that stores and releases electrical energy. In its most basic form, a capacitor consists of two conductive plates separated by an insulating material known as a dielectric.

When voltage is applied to the plates, an electric field forms, causing positive and negative charges to accumulate on the plates.

This stored energy can later be discharged when needed. The capability of a capacitor to store energy is measured in Farads (F) and is referred to as its capacitance.

Connection Between a Capacitor and a Capacitive Liquid Level Sensor:

The principle behind a Capacitive Liquid Level Sensor is intrinsically tied to the concept of capacitance. Here’s how they relate:

Formation of a Capacitor:

In the context of a capacitive liquid level sensor, the probe (or immersed electrode) acts as one plate of the capacitor, and the opposing electrode (often the container or tank wall) serves as the other plate.

Role of the Liquid (Dielectric):

The liquid whose level is being measured acts as the dielectric medium in this capacitor setup. Different liquids have different dielectric constants, which can affect the capacitance.

Changing Capacitance:

As the level of the liquid changes, the portion of the probe submerged in the liquid varies. This changes the effective dielectric between the capacitor plates, leading to a change in capacitance. This variation in capacitance is directly proportional to the level of the liquid.

Measurement Principle:

The electronics in the sensor detect these changes in capacitance. By monitoring these changes, the sensor can determine the liquid’s level and convert it into a readable signal.

While a capacitor is a foundational component in electronics for energy storage, the principle of capacitance is what allows a Capacitive Liquid Level Sensor to function. The sensor effectively creates a dynamic capacitor whose properties change based on the liquid’s level, making it an ingenious application of basic electronic principles to real-world measurement challenges.

Capacitive liquid level sensor working principle

The Capacitive liquid level sensor is used to measure the change of capacitance to measure the level of the liquid level. The capacitive liquid level sensor is used to measure the change of capacitance to measure the unevenness of the liquid level.

The capacitive liquid level sensor is a metal rod pierced into the liquid container. The metal rod serves as a pole of the capacitor. The container wall serves as the other pole of the capacitor. The medium between the two electrodes is the liquid and the gas above it.

Because the dielectric constant ε1 of the liquid is different from the dielectric constant ε2 on the liquid surface. For example ε1>ε2.
Then when the liquid level rises, the total dielectric constant between the two electrodes of the capacitive liquid level gauge increases accordingly, so the capacitance increases.
Conversely, when the liquid level drops, the value of ε decreases and the capacitance also decreases.

Therefore, the Capacitive liquid level sensor can measure the unevenness of the liquid level by changing the capacitance between the two electrodes. The sensitivity of the Capacitive liquid level sensor mainly depends on the difference between the two dielectric constants.

Moreover, as long as ε1 and ε2 are stable, the liquid level measurement is accurate. Because the measured medium has conductivity. Therefore, the metal rod electrode is covered by an insulating layer.

The capacitive liquid level sensor is small in size, simple to complete remote transmission and scheduling, suitable for liquid level measurement of corrosive and high-pressure media.

Extended Reading: GWR Level Sensor for High Temperature & High Pressure

Let’s watch a video. It will help you understand the working principle of the capacitive liquid level sensor.

Video source: https://www.youtube.com/watch?v=0du-QU1Q0T4

Extended reading: Non-Contact Level Measurement

Advantages of Capacitance Level Sensors:

  • Versatility: These sensors perform well with various dielectric fluids, making them suitable for a wide range of applications.
  • Durability: Their robust design, often using stainless steel, means they are resistant to most fluids and harsh conditions. This ensures a long service life.
  • No Moving Parts: Their absence of moving components ensures they require minimal maintenance, which is particularly advantageous in challenging environments.
  • High-Temperature Compatibility: Since they don’t have sensitive components submerged in the liquid, they can operate in hotter fluids where some other sensors might struggle.
  • Sealed System Compatibility: Their design allows them to function efficiently in sealed pressurized or evacuated vessels without any significant impact on performance.
  • Simplicity: With a straightforward mechanical structure, they are less prone to mechanical breakdowns.

Disadvantages of Capacitance Level Sensors:

  • Conductive Fluid Limitation: These sensors might face challenges with conductive fluids unless they come with an insulated outer tube.
  • Coating Issues: Thick or sticky media might coat the probe, creating an insulation layer that can lead to malfunctions or compromised performance.
  • Calibration Necessity: They require calibration to distinguish the difference between liquid and air accurately. This might need occasional recalibration based on the medium.
  • Dielectric Constant Sensitivity: Changes in the medium that cause the dielectric constant to shift can impact the sensor’s performance.
  • Possible Obstruction: The probe might protrude into the liquid, causing obstruction, attracting fouling, or even raising hygiene concerns in certain applications.

Capacitive level sensor Applications

The capacitive liquid level sensor is used to measure the liquid level (level) of conductive and non-conductive liquids (solids) under pressure in pressure vessels.

A capacitive liquid level sensor can convert the changes of various liquid level parameters into standard current signals. Remote transmission to the operating room. For the secondary instrument or computer device for centralized display, start emergency signal or automatic control.

Combine the user’s specific process conditions, equipment structure, and use requirements. Through the flexible combination of the material, structure, and installation method of the level gauge. It is suitable for continuous detection of liquid level, material level or material level under special conditions such as high pressure, high temperature, strong corrosion, easy crystallization, anti-blocking, anti-freezing, and solid powder and granular materials. It can be widely used in detection and control in various industrial processes.

Capacitive level sensor application:

  • Conductive, insulating liquid-chemical industry, oil field, water and sewage treatment
  • Conductive and insulating slurry-papermaking, pharmaceutical, water and sewage treatment
  • Powder, ash, powder-power plant, metallurgy, cement
  • Pellets, coal, grain-power plants, metallurgy, grain
  • Interface, two different liquids-oil field, chemical industry

Extended reading: Radar Liquid Level Sensor|Corrosive, steam, volatile liquids

Extended reading: Radar Water Level Sensor Applications

Capacitive oil level sensor

The capacitive fuel level sensor refers to a capacitive liquid level transmitter used to measure the oil level. According to the principle of capacitance sensing, when the height of the measured electrode dips and changes, the capacitance of the measured electrode changes. It can convert the change of oil level into a standard current signal. It is remotely transmitted to the operation control room for the secondary instrument or computer device for centralized display, alarm, or automatic control.

Read more about Capacitive Fuel Level Sensor

Extended Reading: Low Cost Float Level Sensor for Tank Liquid Volume Monitoring

Capacitive sensor for water level measurement

A capacitive water level sensor is often used to measure the water level of the water storage tank. The capacitive water level sensor uses the change of measuring capacitance value to measure the height of the liquid level. The main function is to continuously measure the liquid level of the measured medium liquid. For example, common media are sewage, mud, paper pulp, eight-treasure porridge, and so on. You may also have heard of a non-contact capacitive water level sensor. It is a kind of capacitive water level sensor installed externally.

Read More about Contact and Non-contact | Capacitive water level sensor

Read more about: Hydrostatic Submersible Level Transmitter-Straight Rod Insertion

Capacitive level switch

The principle of a Capacitive level switch is a position sensor with switch output.

The capacitive level switch is composed of an electronic circuit module unit and sensor rod. The induction pole and the barrel wall are used as the two electrodes of the capacitor.

When the material between the two electrodes changes, the capacitance value changes. After the electronic circuit unit detects this capacitance value change. The analysis and processing unit are compared with the set capacitance value. When it is higher than the set value, a switch signal is an output.

It is widely used for position detection in various high temperature, high pressure, strong acid and strong alkali, and various powder and particle environments in petroleum, chemical, metallurgical, light industry, coal, cement, grain, and other industries.

Extended reading: Diesel fuel tank level gauges & indicators

Extended Reading: What is level transmitter working principle?

Extended reading: Ultrasonic liquid level sensors

More Featured Level Senors

SI-151 Hydrostatic Level Sensor
SI-10 Liquid pressure sensor
SI-PCM261 Submersible Pressure Transducer
SI-PCM260 Deep Well Water Level Sensor
Remote Seal Differential Pressure Transmitter
Differential pressure(DP) level transmitter

Extended reading: Ultrasonic level transmitter for Hazardous Liquids

Related Blog

Extended reading: Corrosive Liquid Chemical Level Sensor in Chemical Processing

Sino-Inst offers over 10 Capacitive Level Sensors for level measurement. About 50% of these are RF level meters, 40% is the tank level sensor.

A wide variety of Capacitive Level Sensors are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of Capacitive Level measurement instrumentation, located in China.

Request a Quote

Please enable JavaScript in your browser to submit the form

Gear Flow Meter-High Viscosity Fluid-Micro Flow Solution

Posted on by

A gear flow meter is a common positive displacement flow meter. The gear flow sensor has built-in double gears to operate. The volume of the medium is calculated by the volume of the gear. The flow rate of the small fluid medium is measured.

  • It can measure fluids with a viscosity of up to 10000 Pa.s.
  • The lowest flow rate can be measured 0.6L/H. That is 0.0026 GPM.


Gear flow meters can be used for resin and glue flow measurement. Flow measurement of hydraulic oil, lubricating oil, and grease. Maltose, syrup. Fuel oil flow measurement. Flow measurement of ink and asphalt. Flow measurement of liquid nitrogen, freezing liquid, and solvent. Edible oil, fish oil, and food filling measurement. Chemical and anti-corrosion requirements fluid measurement. A fluid quantitative control system, etc.

Get a Quote More flowmeters

What is gear flow meter?

The gear flowmeter is a positive displacement flowmeter. It is a high-precision transmitter for measuring volumetric flow. It uses two or more elliptical gears to rotate at right angles to each other to form a T shape. With the flow of the medium, the gears mesh and rotate. Under the action of the fluid flow, a pressure difference is formed at both ends of the instrument inlet and outlet. No power supply is required. A pair of gears rotate freely. The cavity between the gears is filled with liquid. The liquid is discharged as it rotates. Measure the number of revolutions of the gear to know the flow rate of the liquid flowing through the instrument.

Gear flow meters are used to accurately measure the flow or instantaneous flow of liquid in the pipeline continuously or intermittently. It is especially suitable for the flow measurement of Maltose, syrup. heavy oil, polyvinyl alcohol, resin, and other high viscosity media.

There are various types of gear flow meters, mainly named after the shapes of internal components. For example, the circular gear flowmeter we will introduce in this article. There are also common oval gear flow meters, helical flow meters, etc.

Oval gear flowmeter
The oval gear flowmeter uses two oval gears to mesh and rotate. It is suitable for flow measurement of medium with higher viscosity.

Extended reading: Positive displacement flow meter working principle

Helical flow meter
The metering part of the spiral rotor flowmeter is mainly composed of a metering box and a pair of uniquely designed spiral rotors.

Extended reading: Cylinder Gear flow meter for micro flow measurement.

Circular gear flowmeter (spur gear flowmeter)
The circular gear flowmeter uses two circular gears to mesh and rotate. Suitable for microflow measurement.

Tool: Volumetric Flow Rate & Pipe Diameter to Flow Speed Calculator

Gear flow meter

Gear flow meter for Micro flow

A gear flow meter is a micro digital positive displacement flow meter. Can measure very small flow rates and quantify small volumes of liquid. High and low-temperature resistance (-196℃-200℃).

The Gear flow meter for Microflow is made of stainless steel and is used for precise continuous or intermittent measurement of the flow or instantaneous flow of liquid. It is especially suitable for the flow measurement of heavy oil, polyvinyl alcohol, grease, and other high-viscosity media.

It can measure fluids with a viscosity of up to 10000 Pa.s.
The lowest flow rate can be measured at 0.6L/H. That is 0.0026 GPM.

Extended reading: Micro flow meters for low flow liquids

Gear flow transmitter is a type of positive displacement flow transmitter. It is a high-precision transmitter for measuring volume flow.

With the flow of the medium, the gears mesh and rotate. Under the action of the fluid flow, a pressure difference is formed at both ends of the instrument inlet and outlet. There is no need for a power supply. A pair of gears rotate freely. The cavity between the gears is filled with liquid. Discharge and measure the number of revolutions of the gear to know the flow of liquid and liquid flowing through the instrument.

Extended reading: Fluid flow meter types

Figure 1 Schematic diagram of fluid flow

The rotation speed of the round gear transmitter is detected by the sensor coil in the signal amplifier mounted on the watch case. The signal amplifier is not in contact with the measured medium. When the transmitter gear cuts the magnetic field lines generated by the permanent magnet in the housing, it will cause the magnetic flux in the sensing coil to change.

The sensing coil sends the detected magnetic flux periodic change signal to the preamplifier, amplifies and reshapes the signal, generates a pulse signal proportional to the flow rate, and sends it to the unit conversion and flow integration circuit to obtain and display the cumulative flow value. At the same time, the pulse signal is sent to the frequency current conversion circuit, which converts the pulse signal into an analog current quantity, and then indicates the instantaneous flow value.

The round gear transmitter has high machining accuracy and precise installation. The rotation of the gear is scanned non-contact, and each tooth generates a pulse with a very high resolution. Cylindrical gear transmitters can measure very small flow and quantify the small volumes of liquid.

Extended reading: Positive Displacement Flow meter Technology

Extended reading: Food grade flow meters for Food & Beverage industry

Helical gear flow meter

PD Flow Meter is referred to as a positive displacement flow meter. Helical Gear-PD Flow Meter is also called, spiral double rotor flowmeter, LLT, LZ double rotor flowmeter, or UF-Ⅱ spiral rotor flowmeter.

As a high-precision flow meter, PD Flow Meter has an accuracy of 0.2 level. It is especially suitable for the measurement of industrial liquids such as crude oil, refined oil, and light hydrocarbons. It is a new generation volumetric flowmeter. Because it uses a pair of spiral rotors with special teeth, it is also called “Helical Gear Flowmeter”.

Extended reading: Flat Pressure Sensor for High Viscosity Fluids

The flow meter is mainly composed of a body, a pair of spiral rotors, a magnetic coupling, a reduction mechanism, an adjusting gear, a counter, and a signaling device.

The number of revolutions of the spiral rotor is transmitted to the meter head counter through a reduction mechanism composed of magnetic coupling and a series of gears.

The magnetic coupling is mainly composed of active magnetic steel and driven magnetic steel. The use of magnetic coupling can increase the working pressure and working temperature of the flowmeter, ensure safe operation, and reduce maintenance work.

Extended Reading: Rotameter vs Flow meter

The measurement chamber mainly has a sealed cavity formed by a pair of special rotors and cover plates as the flow measurement unit.

The rotor is driven by the pressure difference between the inlet and outlet of the flowmeter to rotate, so as to continuously measure the liquid at the inlet to the outlet after being measured in the sealed cavity.

The amount of liquid flowing through each revolution is eight times that of the sealed cavity in the figure. The total number of rotor rotations and the speed of rotation are transmitted to the counting mechanism by the sealed coupling. Then there is pointer display and word wheel accumulation, you can know that it passes through the pipeline Total amount of liquid.

A pulse transmitter can also be installed in the counting mechanism, which becomes a flow meter with a signal.

Matching with the company’s electric display instrument, it can realize remote transmission (quantity, accumulation, instant, and other functions) automatic measurement and control.

Read more about Liquid Flow Meters Guide

Oval gear flow meter

Oval gear flow meter is one of the typical positive displacement flow meters. Measure the flow of liquid filling the pipeline under a certain pressure.

The oval gear flow meter is a pointer display type positive displacement flowmeter. The word wheel accumulates counting and can be equipped with a zero return device. Oval gear flowmeters are widely used in liquid flow control in various industrial fields. Applicable to various types of liquid measurements, such as crude oil, diesel, gasoline, etc. Choose different manufacturing materials, such as crude oil, diesel, gasoline, etc. can be measured.

Extended reading: How to choose a high viscosity flow meter?

The oval gear flowmeter is composed of a metering box and a pair of elliptical gears installed in the metering box, and the upper and lower cover plates form a sealed crescent-shaped cavity (due to the rotation of the gear, it is not sealed) as the calculation unit of a displacement.

The flow meter is mainly composed of a housing, a counter, an elliptical gear, and a coupling (magnetic coupling and axial coupling), etc. As shown in the figure.

1.Counter 2. Transmitter

3. Accuracy adjuster (used above DN50)

4. Sealed coupling

5. Front cover 6. Cover plate

7. Oval gear 8. Shell

9. Rear cover

When the measured liquid enters the flowmeter through the pipeline, the pressure difference generated at the inlet and outlet pushes a pair of gears to continuously rotate, and the liquid measured by the crescent-shaped cavity is continuously transported to the outlet. The product of four times the secondary displacement is the total amount of the measured liquid flow.

The elliptical gear generates a torque to make it rotate under the action of the pressure difference △p of the measured medium.

The rotor 1 and rotor 2 are alternately driven by one to rotate the other. There are two magnets on each rotor as signal generating elements. There is a magnetic signal detecting element at the center of the two axes at the bottom of the cavity. Whenever the magnet turns to the detecting element, the sensor counts as a pulse.

Each pulse corresponds to a certain amount of medium discharge F, F=XXml/p, so the volume flow Qm per unit time can be obtained: Qm=F*H, F is the amount of medium removed by each pulse; H pulse per unit time number.

Read more about Mass Flow Rate vs Volumetric Flow Rate

Explore Oil and Gas Flow Meters

Mirco flow-high viscosity fluid measurement

High-viscosity liquid means that the liquid is viscous and thick, which is different from general liquids and non-Newtonian fluids (mud, pulp). The activity is slow and it is very difficult to filter by simple methods.

What’s more, in addition to some dust, the liquid also contains colloidal particles that are not completely dissolved.

For example solutions such as rubber, paraffin, cellulose acetate, viscose, polyacrylonitrile, paint and animal glue.

Read more about Liquid Flow Meters Guide

Gear flowmeter is a new type of volumetric flow transmitter, used for precise continuous or discontinuous measurement of the flow or instantaneous flow of liquid in the pipeline. Cylindrical gear flowmeter is especially suitable for heavy oil, polyvinyl alcohol, resin and other viscosities. Flow measurement of high media.

It can measure fluids with a viscosity of up to 10000 Pa.s.
The lowest flow rate can be measured at 0.6L/H. That is 0.0026 GPM. Read more about: what is gpm;

Model

Measure Range

L/H

K

P/L

Pressure-Bar

Temperature

Accuracy

Interface

Installation dimensions

Aluminum alloy

stainless steel

GF02

0.6-50

10500

150

400

-15-80℃

+/- 0.5%

( Range 1:10)

+/- 1.0%    （Range 1:100）

G1/8

Φ84*55

GF04

5-250

9117

150

400

-15-80℃

G1/4

Φ84*55

GF06

10-500

3000

150

400

-15-80℃

G1/4

Φ84*67

GF10

50-1200

1280

150

400

-15-80℃

G1/2

Φ84*67

GF15

200-3000

126.75

150

400

-15-80℃

G3/4

Φ116*98*74

GF25

1000-12000

61.1

150

400

-15-80℃

G1-1/2

158*118*68

GF32

2000-20000

59.9

150

400

-15-80℃

G1-1/2

158*18*68

Extended Reading: Insertion Flowmeter Types

Cylindrical gear flow meters are small in size and light in weight.
During operation, the vibration and noise are small and the operation is stable.
It can also be used to measure the small flow rate of small pipe diameters.
The starting flow is small, and the range ratio is wide, suitable for measuring the liquid flow with large fluctuations.
The measurement accuracy is not affected by changes in pressure and flow, with stable performance, long life and large flow capacity.

Read More about: Chemical Flow Meter Guide

Related Products:

Gear flow meter for Micro flow
LCD display Oval Gear High Viscosity Flow Meter
High Temperature Oval Gear Flow Meter – Heating oil
Oval Gear-Marine Fuel Flow Meter
Thermal insulation Oval Gear flow meter
Clamp Filling Oval Gear Positive Displacement Flow Meter
Pointer Type Oval Gear Flow Meter
Micro Flow Meter
Helical Gear-PD Flow Meter
Liquid Roots Meter
Rroots Gas Meter

Related Blogs:

Gas Rotameter Tips

What is Gas Rotameter? Rotameter is also called float flowmeter. It is often called…

Solvent flow meters

The solvent flow meter is a flow meter that can measure solvent volume or…

Grease Flow Meters

What is a Grease Flow Meter? Grease Flow meters are meters dedicated to measuring…

Refrigerant Flow Meter

Refrigerant flow meter is used for common liquid and gas refrigerant flow measurement. Sino-Inst…

Diesel Fuel Flow Meters

Diesel Fuel flow meters are digital flow meters for liquid fuel consumption measurement. Featured…

Extended reading: Oil Level Measurement Solutions for the Oil & Gas Industry

Sino-Inst, Manufacturer for Gear flow meter for Microflow. For example crude oil flow meter, diesel flow meter, gasoline flow meter.

Sino-Inst’s Gear flow meter for Microflow, made in China, Having good Quality, With better price. Our flow measurement instruments are widely used in China, India, Pakistan, the US, and other countries.

Contact and Non-contact | Capacitive water level sensor

Posted on by

A capacitive water level sensor is often used to measure the water level of the water storage tank. The capacitive water level sensor uses the change of measuring capacitance value to measure the height of the liquid level. The main function is to continuously measure the liquid level of the measured medium liquid. For example, common media are sewage, mud, paper pulp, eight-treasure porridge, and so on. You may also have heard of a non contact capacitive water level sensor. It is a kind of capacitive water level sensor installed externally.

Get a Quote Level Sensors

What is a capacitive liquid level sensor?

The Capacitive liquid level sensor is based on the principle of capacitance sensing. When the height of the measured electrode is changed by the measured medium, it will cause its capacitance to change. It can convert the changes of various material levels and the height of liquid level media into standard current signals, which are remotely transmitted to the operation control room for centralized display, alarm or automatic control by secondary instruments or computer devices.

Capacitive liquid level sensor has a good structure and installation method, which can be applied to high temperature, high pressure, strong corrosion, easy to crystallize, anti-clogging. Anti-freezing and solid powdery and granular materials.

The Capacitive liquid level sensor fundamentally deals with the influence of factors such as temperature, humidity, pressure, and material conductivity on the measurement process. Therefore, it has extremely high anti-interference and reliability. It can measure strong corrosive liquids, such as acid, alkali, salt, sewage, etc.

Can measure high temperature and high pressure medium. Process temperature -40~600℃. Process pressure -0.1~4.0MPa.

A single intelligent integrated capacitance level gauge has common two-point on-site calibration skills, which provides convenience for users to easily use the product.

Capacitive liquid level sensor can measure the liquid level of strongly corrosive medium, measure the liquid level of high temperature medium, measure the liquid level of sealed container. It has nothing to do with the viscosity, density and working pressure of the medium.

Extended reading: Ultrasonic liquid level sensors

Capacitive water level sensor

Can capacitive liquid level sensors measure water?

OK. Because water is conductive. Except for pure water, ultra-pure water, industrial water has no special instructions, it is generally regarded as a conductor.

Capacitive water level sensor is when measuring water. The water contains rust, jelly, etc. Will it cause measurement fluctuations?

probably not. When measuring water, there are two plates: one is the metal rod of the capacitor itself. And the other is actually water. Because general water is conductive. The dielectric is actually the film on the outside of the Capacitive water level sensor metal.

  1. When the tank is a conductor: because water is conductive. Except for pure water, ultrapure water, industrial water without special instructions is generally regarded as a conductor. So it forms the other plate of the capacitor. When the metal tank is used to measure the conductor level with a capacitor, the dielectric is the layer of PTFE.
  2. If the tank body and process connection are non-conductive materials. Then, a conductor should be led down from the ground terminal of the meter casing along the outside of the tank as another plate. The dielectric at this time is membrane + medium + tank wall.
RF Admittance Level Sensor
Capacitance Level Transmitter

Non contact capacitive water level sensor

Non contact capacitive water level sensor, you only need to attach the sensor to the outer wall of the container made of insulating material when using it.

When the liquid level reaches the sensor detection position, there is a level signal output. It is easy to install and use, no need to open holes, and durable life. Capacitive type can detect the liquid level through the medium. No direct contact with liquid is required. It will not be affected by corrosive effects such as strong acids and alkalis, and it is more hygienic.

Extended reading: Radar Non Contact Water Level Sensor

Features of Non contact capacitive water level sensor:

  1. Small size and high cost performance. Waterproof grade IP62. Ultra low standby function
  2. The liquid level can be detected through the medium without direct contact with the liquid. It will not be affected by corrosive effects such as strong acids and alkalis, and it is more hygienic.
  3. No need to open holes without mechanical parts inside. Only need to be installed on the outer wall of the container to achieve non-contact use
  4. Integrated filtering, debounce, and A/D conversion circuit. Directly output high and low levels.
  5. Accuracy, high reliability, no virtual area, no gray sensing area
  6. Meet the requirements of safety standards
  7. Comply with RoHS requirements
  8. The sensitivity can be matched according to the customer’s application

Non contact capacitive water level sensor application:
It can be used to detect water purification, sewage, oil, wine, various acid-alkaline liquid levels, etc. Mainly suitable for household appliances, medical equipment, chemical equipment, business machines, etc. Your equipment needs level control. Our products will meet your liquid level measurement needs.

Extended reading: Ultrasonic level transmitter for Hazardous Liquids

Compared with non contact capacitive water level sensor and float type liquid level sensor:

  1. It can be used when installed on the outer wall of the container, and the container does not need to be opened. The water level can be detected non-contact.
  2. Small size, small space required for installation
  3. The float type liquid level sensor needs to be in contact with the liquid to detect the liquid level. The internal magnet will adsorb impurities in the water to form scale. Scale will cause the weight of the float to increase and affect the accuracy of liquid level detection. The Non contact capacitive water level sensor does not directly contact the liquid, and there is no such restriction.
  4. The float type liquid level sensor uses the rise and fall of the liquid level to drive the movement of the float with a magnet. So that the internal dry reed switch is turned on and off. Therefore, the float type liquid level sensor has a certain draft, the float is easy to jam, and the reliability is low. The Non contact capacitive water level sensor has no mechanical moving parts and has high reliability.

SI-U01 Float Level Sensor
SI-U02 Multi-Point Liquid Level Float Switch
SI-U03 Float Switch Water Level Controller
SI-U04 Magnetic Float Level Sensor-Reed Switch
SI-U05 Cable Float Level Sensor & Swtich

Frequently
Asked
Questions

Help Center

  1. Under stable working conditions, due to structural limitations, the compensation problem of system measurement errors caused by the adiabatic temperature of the water side cannot be completely solved. Under accident conditions such as boiler shortage or full water, excessive system measurement errors may bring serious consequences
  2. The structure is complex, and there are many static sealing points. The scale of construction is large and there are problems of heat preservation in winter.
  3. The measurement time lag is long, and the boiler water level change cannot be reflected immediately. The quality of the measurement signal adjustment is poor.
  4. Due to the exothermic heat of the condensing cylinder, the use cost is extremely high.

Extended reading: Amazing Solutions for Continuous Liquid Level Measurement

The capacitance level switch determines whether there is liquid by detecting the conductivity or insulation rate of the medium. It can be simply understood as judging whether the liquid has reached a fixed water level according to the size of the capacitance value. The capacitor is formed between the liquid level switch and the medium in which it is located. When liquid is detected, the capacitance value changes greatly.

Extended reading: Radar Level Sensor Working Principle

More Water level sensors

Water depth sensors are also known as water level sensors. Water depth sensors are often used to measure tank levels, well depths, river depths, etc. There are many different types of water depth sensors. All of them are used to measure the water level by submerging underwater or above the water surface. Then, they are converted into a water depth or water level signal. For example, submersible hydrostatic level meter, ultrasonic level meter, etc.

SI-151 Hydrostatic Level Sensor
SI-10 Liquid pressure sensor
SI-PCM261 Submersible Pressure Transducer
SI-PCM260 Deep Well Water Level Sensor
Remote Seal Differential Pressure Transmitter
Differential pressure(DP) level transmitter

Extended reading: Non contact level measurement

Sino-Inst offers over 20 Capacitive water level sensors for level measurement.

About 50% of these are liquid level meters, 40% is the tank level sensor.

A wide variety of Capacitive water level sensors options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of level measurement instrumentation, located in China.

Request a Quote

Please enable JavaScript in your browser to submit the form