What is sludge blanket level?

Sludge (sludge) is a solid settling material produced by water and wastewater treatment processes. The sludge blanket level is the interface between the settled sludge and the turbid or clear water phase above. The sludge level can be the distance from the water surface (sludge level depth) or the distance from the bottom of the tank (sludge level height).

Due to the highly variable nature of all types of sludge, classification is essential, and its treatment and disposal are different. According to its origin, it can be classified as

• Municipal sludge (civil sludge, also called drainage cement sewage sludge,). It mainly refers to sludge from sewage plants, which is the largest category of sludge in terms of quantity. In addition, sludge from waterworks can also be included in this category.
• Pipe network sludge, sludge from drainage collection systems.
• River and lake sludge, sludge from rivers and lakes.
• Industrial sludge, from a mixture of solids and water, oil, chemical pollution, and organic matter produced by various industrial production.

In (waste) water treatment and process control, sludge water level is an important parameter. Especially in the process of phase separation, accurate sludge level information is crucial. Automatic Sludge Blanket Level Detector can be installed in clear, turbid or even heavily contaminated media with high concentration of suspended matter.

Extended Reading: How many types of level transmitters are there?

Sludge Blanket Level Detector Appliactions

• Waste treatment clarifiers.
• Primary sedimentation tanks, secondary sedimentation tanks, gravity sedimentation tanks.
• Petroleum/asphalt separation tanks.
• Paper pulp tanks.
• Beverage water clarifiers.
• Mining clarifiers.
• Brine tanks.
• Slurry tanks.
• Any vessel in which a liquid/solid two-phase interface exists.

Extended reading: cryogenic fuel level indicator

Sludge Blanket Level Measurement Cases

Extended reading: How to Choose the Right Diesel Fuel Level Sensor?

More Featured Ultrasonic Level Meters

More Level Measurement Solutions

Sino-Inst is Manufacturer of Automatic Sludge Blanket Level Detector. We supply more than 20 kinds of Ultrasonic Level Sensors. 40% ultrasonic level meters, 40% External Ultrasonic Liquid Level Meters and 20% Automatic Sludge Blanket Level Detectors.

Automatic Sludge Blanket Level Detector reference wholesale price USD 755.00/set

Automatic Sludge Blanket Level Detector is commonly used for sludge interface measurement in primary and secondary settling tanks, sludge thickening tanks in wastewater treatment. And sedimentation tank level measurement in water treatment plants.

It is also widely used in industries that require solid-liquid separation in production processes such as paper, mining, power, and petroleum. Monitoring the height of solids in the sedimentation process. For example, oil/asphalt separation tank, paper pulp tank, power mortar sedimentation tank, mining clarification tank, etc.

Automatic Sludge Blanket Level Detectors enable stable level measurement without tank modifications. This greatly meets the measurement needs of many applications. Can be used from small to large tanks.

Sino-Inst’s Automatic Sludge Blanket Level Detectors, made in China, Having good Quality, With better price. Our level measurement instruments are widely used in China, India, Pakistan, the US, and other countries.

The entire team at Sino-Inst’s has received excellent training, so we can ensure that every client’s needs are met. For assistance with your product requirements, whether it’s a Automatic Sludge Blanket Level Detector, flow sensor, or other device, give us a call.

Request a Quote

Featured Diesel Level Sensors

Types of Fuel-Diesel Level Sensors

Below are some of the most commonly used diesel level sensors that we have compiled.

Read More About: Difference Between Class 1 Div 1 And Class 1 Div 2

Fuel-Diesel-Water Tank Level Sensor Monitoring

The oil depot liquid level monitoring system is a multi-functional management system applied to the oil depot, which can effectively manage the inflow, sales and storage of oil products in the oil depot by accurately measuring the oil level, temperature and other data of the oil tank.

Sino-Inst oil depot storage tank monitoring system is based on high-precision Fuel Tank Diesel Level Sensors. Combined with a dedicated regulatory information system. Realize automatic oil measurement and supervision for oil depots.

The system can complete the automatic measurement of the oil in the oil storage tank through each Fuel Tank Diesel Level Sensors when the oil storage tank is closed. Complete the on-site controller to realize the operation, display and remote transmission of the data measured by the liquid level sensor in the entire storage area.

The remote computer combines the received data and passes it through its internal dedicated management software. Realize the analysis of oil parameters in the oil tank, and directly reflect the operation of the storage tank.

Managers can grasp and understand the operation of each storage tank in time through their own computers. So as to reasonably carry out the production arrangement and scheduling.

Extended reading: Advantages of Oval Gear Mechanical Diesel Flow Meters

Water Tank Level Sensors

The Water Tank Level Sensor is an important part of the water tank level control system. Using a level sensor for the water tank, solenoid valve, control box, liquid level switch and other accessories can effectively form a Water Tank Level control system. Monitor the materials stored in the water tank. Master important data such as its liquid level, reserves, and quality. A reasonable liquid level can ensure the safe, reliable, and efficient operation of the storage tank.

Read more about: Water Tank Level Sensors Types

Propane Level Sensors

Propane tank level indicator is also called propane tank gauge level indicator, or propane tank level gauge. What kind of level gauge is used for Industrial propane level measurement?

Propane is a gas that can be liquefied. Chemical formula CHURCH, colorless, liquefiable gas. Slightly soluble in water, soluble in ethanol and ether.
Common Industrial Propane Tank Level Indicators for Industrial Tank Level Measurement include radar level sensor; magnetostrictive level sensor; float level gauge; magnetic flap level gauge; ultrasonic level gauge.

Read More about: Large Propane Tank Level Indicator

Fuel Level Sensor Monitoring & Measurement Solution

Sino-Inst is Manufacturer of diesel level sensors. We supply more than 20 kinds of diesel level sensors for Tanks. 40% submersible level meters, 40% External Ultrasonic Liquid Level Meters and 20% other types level sensors.

Diesel level sensors for Tanks are mainly used for level measurement of various oils.
It can measure even liquids such as water, seawater, oil, and slurry.

diesel level sensors for Tanks enable stable level measurement without tank modifications. This greatly meets the measurement needs of many applications. Can be used from small to large tanks.

Sino-Inst’s diesel level sensors for Tanks, made in China, Having good Quality, With better price. Our level measurement instruments are widely used in China, India, Pakistan, the US, and other countries.

The entire team at Sino-Inst’s has received excellent training, so we can ensure that every client’s needs are met. For assistance with your product requirements, whether it’s a diesel level sensors for Diesel Tanks, flow sensor, or other device, give us a call.

Request a Quote

Featured Non Contact Level Transmitters for Sale

Non Contact Level Transmitters Types

In order to choose the most suitable level sensor, we not only need to know the properties and state of the liquid being measured. It is also necessary to understand the advantages and disadvantages of different level sensors. in order to select the most suitable sensor. Next, let’s briefly introduce the common non-contact liquid level measurement methods and their characteristics.

Common non-contact measurement methods mainly include ray level meter, ultrasonic level meter, laser ranging sensor and radar level meter.

Radar Type Level Transmitter Working Principle

Very short microwave pulses with very low energy are transmitted and received through the antenna system. The radar wave runs at the speed of light. The operating time can be converted into level signals by electronic components. A special time extension method can ensure stable and accurate measurement in a very short time.

Electromagnetic waves propagate in the air at the speed of light. The distance between the radar level gauge and the surface of the material can be expressed by the following formula: 　　

D = (1/2)*CT

In the formula:

D ———the distance between the radar level gauge and the surface of the material; 　　

C ———Speed of light 　　

T ———Pulse time.

Then the liquid level is: 　　L = E-D

In the formula:

L — liquid level; 　　

E ———The total height of the tank; 　　

D ———Air height.

Even in the presence of false reflections, the new micro-processing technology and the unique ECHOFOX- software can accurately analyze the level echo. By inputting the size of the container, the distance value can be converted into a signal proportional to the level. The instrument can be debugged with empty positions.

Extended reading: Amazing Solutions for Continuous Liquid Level Measurement

Ultrasonic Level Transmitter Working Principle

The working principle of the ultrasonic level sensor is:

Ultrasonic transducer (probe) emits high-frequency pulse sound waves, and the surface of the measured level (material) is reflected back. The reflected echo is received by the transducer and converted into an electrical signal. The propagation time of the sound wave is proportional to the distance from the sound wave to the surface of the object.

The relationship between the sound wave transmission distance S and the sound speed C and the sound transmission time T can be expressed by the formula: S=C×T/2.

The probe part emits ultrasonic waves, which are then reflected by the liquid surface. The probe part is received again. The distance from the probe to the liquid (object) surface is proportional to the elapsed time of the ultrasonic wave:
hb = CT2
Distance [m] = time × speed of sound/2 [m]
The temperature compensation formula of sound velocity:
Ambient sound velocity = 331.5 + 0.6 × temperature

Read More about: List of Differences: Radar vs Ultrasonic Level Measurement

Non Contact Level Transmitters Industrial Applications

Sino-Inst’s Non Contact Level Transmitters, whether ultrasonic level meter or radar level meter, are widely used in various industries.

• Chlor-alkali
• Storage and transportation
• petrochemical
• Coal chemical industry
• oil refining
• Fluorine chemical
• fertilizer
• pesticide
• electricity
• liquid storage
• other industry

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

More Non-Contact Liquid Level Measurement Solutions

Read more about: River Water Level Monitoring System

Sino-Inst is Manufacturer of Non Contact Level Transmitters. We supply more than 20 kinds of Non Contact Level Transmitters. 40% ultrasonic level meters, 40% radar level transmitters and 20% other types of flowmeters.

Non Contact Level Transmitters are mainly used for level measurement of various liquids and solid particles.
It can measure even liquids such as water, seawater, oil, and slurry.

Non Contact Level Transmitters enable stable level measurement without tank modifications. This greatly meets the measurement needs of many applications. Can be used from small to large tanks.

Sino-Inst’s Non Contact Level Transmitters, made in China, Having good Quality, With better price. Our level measurement instruments are widely used in China, India, Pakistan, the US, and other countries.

The entire team at Sino-Inst’s has received excellent training, so we can ensure that every client’s needs are met. For assistance with your product requirements, whether it’s a Non Contact Level Transmitters, flow sensor, or other device, give us a call.

Request a Quote

Commonly used dielectric constant table

gas	temperature(℃)	Relative dielectric constant	liquid	temperature(℃)	Relative dielectric constant
water vapor	140~150	1.00785	solid ammonia	-90	4.01
gaseous bromine	180	1.0128	solid acetic acid	2	4.1
helium	0	1	paraffin	-5	2.0~2.1
hydrogen	0	1.00026	polystyrene	20	24~2.6
oxygen	0	1.00051	wireless porcelain	16	6~6.5
nitrogen	0	1.00058	UHF porcelain		7~8.5
Argon	0	1.00056	barium dioxide		106
gaseous mercury	400	1.00074	rubber		2~3
Air	0	1	hard rubber		4.3
hydrogen sulfide	0	1.004	Paper		2.5
vacuum	20	1	dry sand		2.5
ether	0	4.335	15% water wet sand		约9
liquid carbon dioxide	20	1.585	wood		2~8
methanol	20	33.7	amber		2.8
Ethanol	16.3	25.7	ice		2.8
water vapor	14	81.5	shellac		3~4
liquid ammonia	-270.8	16.2	Celluloid		3.3
liquid helium	-253	1.058	Glass		4~11
liquid hydrogen	-182	1.22	Yellow phosphorus		4.1
liquid oxygen	-185	1.465	sulfur		4.2
liquid nitrogen	0	2.28	carbon (diamond)		5.5`16.5
liquid chlorine	20	1.9	Mica		6~8
kerosene	20	2~4	granite		7~9
turpentine		2.2	marble		8.3
benzene		2.283	salt		6.2
paint		3.5	Beryllium oxide		7.5
glycerin		45.8

Dielectric constants of common liquids

The relative permittivity of common solvents is at room temperature and the test frequency is 1KHz.

• H2O (water) 78.5
• HCOOH (formic acid) 58.5
• HCON (CH3) 2 (N,N-dimethylformamide) 36.7
• CH3OH (methanol) 32.7
• C2H5OH (ethanol) 24.5
• CH3COCH3 (acetone) 20.7
• n-C6H13OH (n-hexanol) 13.3
• CH3COOH (acetic acid or acetic acid) 6.15
• C6H6 (benzene) 2.28
• CCl4 (carbon tetrachloride) 2.24
• n-C6H14 (n-hexane) 1.88
• n-C4H10 (No. 4 solvent) 1.78

Extended reading: Non contact level measurement

Influence of Dielectric Constant on Guided Wave Radar Level Meter

From the point of view of process conditions, the dielectric constant of the medium to be measured plays a very important role in the measurement of guided wave radar as a known condition.

According to the electrical properties of the dielectric constant, it is roughly divided into three categories: non-polar substances (εr<2.8), weakly polar substances (2.8≤εr≤3.6), polar substances (εr>3.6) .

For liquefied petroleum gas, petroleum, gasoline or other hydrocarbons in petrochemical plants, and petrochemical products, 1.4≤εr≤4.0.
Alcohol, organic solvent, oil-water mixture, etc., 4.0≤εr≤10.0.
Conductive liquids, such as water-based solutions, dilute acids and bases, εr>10.0.

The Guided Wave Radar Level Meter can measure gas/liquid, gas/solid, and liquid/liquid two-phase interfaces.

Ideal for measuring liquid/liquid interfaces, such as oil-water interfaces.

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

The Guided Wave Radar Level Meter emits low-energy pulsed microwaves that are sent down the probe at the speed of light. At the interface between the probe and the medium, a considerable proportion of microwave energy is reflected back to the transmitter through the probe to receive the first echo signal.

A certain percentage of the pulses will continue down the probe, traversing the upper low dielectric constant medium until it is reflected on the lower medium surface and the transmitter receives the second echo.

To measure the boundary, the minimum thickness of the upper medium is 10-20 cm, so that the echoes of the two liquids can be distinguished. The maximum thickness of the upper dielectric depends on its dielectric constant.

The dielectric constant of the liquid in the upper layer is relatively low, and the difference between the dielectric constants of the upper layer and the lower layer liquid is required to be greater than 10, and the upper layer medium εr<3, the lower layer medium εr>20. Only in this way can the obvious reflection effect be obtained. Both level and interface can be measured simultaneously.

The smaller the dielectric constant of the medium, the greater the amplitude of the reflected signal. For the medium with low dielectric constant (1.2≤εr≤2.5), the guided wave radar level gauge can be selected for powdery or volatile medium.

Some substances hinder or absorb electromagnetic waves in the gas phase, and there are substances in the gas phase that weaken electromagnetic waves. For example, dust, powder (graphite, iron alloy, etc.) with high conductivity, or volatile media. For example, the dielectric constant of liquid ammonia is at room temperature 25 ℃. It is 14.9, which is a conductive medium and can be measured effectively.

The advanced Guided Wave Radar Level Meter is especially suitable for measuring a variety of powders. And liquids with inclined liquid levels caused by vortices.

Because the reflected wave does not depend on a “flat” surface to reflect the echo, microwave safe transmission makes the medium surface condition less affected. Disturbed liquid surface or foam formation, as well as different curved surfaces or furnace outlet will not affect the measurement. Therefore the Guided Wave Radar Level Meter also has a good measurement effect in turbulent situations.

From the perspective of measurement range, the medium with higher dielectric constant has better reflection performance and is suitable for longer measurement range. Guided Wave Radar Level Meter adopts two-wire loop power supply, 24V (DC) or 220V (AC) liquid level transmitter, low energy consumption, and meets the control level process requirements.

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

Influence of Dielectric Constant on Radar Level Meter

The Radar Level Meter adopts the principle of transmit-reflection-receive. The antenna of the Radar Level Meter emits electromagnetic waves. These electromagnetic waves are reflected by the surface of the measured object and then received by the antenna. The time from emission to reception of electromagnetic waves is proportional to the distance to the liquid surface.

In the measurement of Radar Level Meter, the measured medium needs to provide sufficient radar reflection signal. In general, the higher the dielectric constant, the stronger the reflected signal. The farther away the target is, the greater the intensity of the reflection is required. In order to have sufficient signal back to the radar transmitter.

When the radar wave reaches the liquid level surface and is reflected. The radar wave will be absorbed and attenuated. When the attenuation is too much, the radar level gauge will not receive enough signal, resulting in inaccurate measurement. This is the dielectric constant of the measured medium. Effects of radar level gauge measurements.

From this point of view, the dielectric constant has an effect on the Radar Level Meter measurement. However, this problem has been well resolved.

The Radar Level Meter can also perform interface measurements, especially on oil-water interfaces.

Principle: When measuring the interface, the part of the pulse that is not reflected on the surface of the upper product will continue down to the surface of the lower product, and then be reflected back.

The requirements for the dielectric constant when the Radar Level Meter measures the interface are as follows:

(1) The dielectric constant of the upper product must be known and must not be changed;
(2) The difference between the dielectric constants of the two products must be greater than 6;
(3) Mainly used in the interface between oil-water liquid and water/water-like liquid with lower dielectric constant of the upper layer (<3) and higher dielectric constant of the lower product (>20).

Extended Reading: What is level transmitter working principle?

Related Level Sensors

Related Level Measurement Solutions

Sino-Inst offers over 50 level sensors for level measurement. About 30% of these are Radar level meters, 30% of these are guided wave radar level sensor, 40% is other tank level sensors.

A wide variety of liquid level meters options are available to you, such as free samples, paid samples.

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

Request a Quote

So why are we talking about liquid volume sensor here? Don’t worry, we don’t have a mature liquid volume sensor. However, we have A dozen ways for liquid level measurement, with different level sensors. Combined with Sino-Inst’s volume recorder. It can collect, display and convert the liquid level of various regular and irregular tanks in the industrial field into the corresponding tank volume. It is suitable for monitoring, controlling and collecting various process parameters.

Featured Level Sensors

Level Measurement Technologies

Liquid Volume Sensor

So far there is no sensor that can measure the volume of liquid. Because there are various shapes of liquid containers, such as cylinders, spheres, rectangles, cylinders and squares with hemispherical ends.

For rectangles, cylinders or squares, the volume and weight of the liquid can be calculated directly by multiplying the floor area of the container by the height of the liquid. And the corresponding relationship is linear. The hemispherical cylinder and sphere at both ends can be calculated by definite integral. The law of curvature change is the volume formula of the function. Calculate the volume and weight of the liquid according to the height of the liquid.

Monitoring liquid volume solutions

Most of our liquid level sensors can output liquid level signals, such as 4-20mA signal, 0-10V signal, RS485 and so on.

However, the liquid level transmitter alone cannot calculate the liquid volume of tanks of different sizes. It’s too complicated. A separate recorder is required to calculate it.

Therefore, the digital display volume meter can collect, display and convert the liquid level of various regular and irregular tanks in the industrial field into the corresponding tank volume. It is suitable for monitoring, controlling and collecting various process parameters.

So, How to measure volume of liquid?

After the liquid level gauge is installed in your tank, Sino-Inst’s volume display controller/recorder can collect, display and convert the liquid level of various regular and irregular tanks on the industrial site into the volume of the corresponding tank . It is suitable for monitoring, controlling and collecting various process parameters.

The volume meter is equipped with volume download software as standard. Form a liquid level volume comparison table. Import volume meter, suitable for volume conversion of various regular or irregular tanks.

The meter is equipped with RS232 communication interface as standard. Connect with the host computer. Through the volume download software, data writing for regular and irregular tanks can be realized. 1000 sets of data can be downloaded.

Volume Recorder

LCD Volume Display Regulator/ Recorder is specifically designed for industrial on-site regular and irregular canned liquid, volume and mass conversion.

It is based on a 32-bit ARM micro-processor and equipped with the secondary meter with high-speed AD and high-capacity storage unit.

The device has empowered by the surface mounting technology, featuring the design of multiple-layered protection and isolation, with a strong anti-interference capability and high reliability.

It has used the embedded operating system with USB data dump function.

The data storage time could reach up to 720 days.

By using U disk and host computer analysis software, one could call and view the historic curve of process variants and relevant historic data from time to time.

It also could match with various liquid sensors, such as ultrasonic liquid level meter. The device has sound anti-theft and anti-damage and other features.

Measurement Input
Input Signal	Current: 0~20mA, 0~10mA, 4~20mA, 0~10mA rooting, 4~20mA rooting
	Input impedance: ≤ 100Ω
	Maximum input current limit: ≤ 30mA
	Voltage: 0~5V, 1~5V, 0~10V (customized), 0~5V rooting, 1~5V rooting,
	Input impedance: ≥ 500KΩ
Output
Output Signal	Analog output: 4~20mA (load resistance ≤ 480Ω), 0~20mA (load resistance ≤ 480Ω), 0~10mA (load resistance ≤ 960Ω), 1~5V (load resistance ≥ 250KΩ), 0~5V (load resistance ≥250KΩ), 0~10 V (load resistance ≥4KΩ) (customized)
	Alarm output: relay control output – AC220V/2A, DC24V/2A (resistive load)
	Feed output: DC24V±1, load current ≤ 50mA
	Communication output: RS485/RS232 communication interface, configurable baud rate of 1200~9600bps, standard MODBUS RTU communication protocol, RS-485 communication distance of up to 1km, and RS-232 communication distance of up to 15m.
General Parameters
Measuring Accuracy		0.2%FS±1d
Setting Mode		Touch-panel-based key setting; password locking of parameter settings; permanent preservation of settings upon power failure.
Display		Backlit 3.5-inch 128*64 high-resolution dot-matrix FSTN LCD
		Support the display of Chinese characters, figures, curves and bar graphs, as well as screen page turning, historical data search and timescale changes of curves etc. through the panel keys
Recording Interval		1, 2, 4, 6, 15, 30, 60, 120, or 240 seconds, nine options available
Storage Length		3 days (with 1-sec interval) – 720 days (with 240-sec interval)
Printing Control		RS-232C printer interface, supporting SP-A40SH series serial printers
Operating Environment		Ambient temperature: 0~50℃; relative humidity: ≤ 85%RH; avoid strongly corrosive gas
Working Power Supply		AC 100~240V (switching power supply), 50/60HZ; DC 20~29V (switching power supply)
Power		≤5W
Structure		-Standard snap-in type

Related liquid level monitoring solutions

Sino-Inst offers over 10 level transmitters for Liquid level measurement.

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

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

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

Request a Quote

Featured water level transmitters for Sale

level transducer types

In various industrial production processes, many auxiliary safety products are used. Among them, level transducer, as one of the most common auxiliary products, has many names. The following are 20 common level transducers:

• Magnetic flap liquid level transducer
• Float level transducer
• Steel belt level transducer
• Radar level transmitter
• Magnetostrictive liquid level transducer
• RF Admittance Level Transducer
• Tuning Fork Level Meter
• Glass plate/glass tube level transducer
• Hydrostatic level transmitter
• pressure level transmitter
• Capacitive Level Transducer
• Intelligent electric displacer liquid level transducer
• Buoy Level Transducer
• Displacer Level Transmitter
• Electric contact level transducer
• Magnetic two-color electronic liquid level transducer
• External level transmitter
• Hydrostatic Level Transducer
• Ultrasonic Level Transducer
• Differential pressure level transmitter (double flange level transmitter)

Extended Reading: What is level transmitter working principle?

types of water level sensors

We can divide Water Level Sensors into two categories by measuring whether they are in contact with the water level.

One type is contact type. Including single flange static pressure/double flange differential pressure level transmitter, float type level transmitter, magnetic level transmitter, input type level transmitter, electric internal float level transmitter Sensors, electric float level transmitters, capacitive level transmitters, magnetostrictive level transmitters, service level transmitters, etc.

The second category is non-contact. Divided into the ultrasonic level transmitter, radar level transmitter, and so on.

Extended Reading: Chilled Water Flow Meter

How does a water level transducer work?

Water level transducer is an instrument that can convert the water level parameter of the measured point into the corresponding electric quantity signal in real time.

The working principle of the Water level transducer is that when it is put into a certain depth in the liquid to be measured. The pressure on the sensor’s front surface is converted into the liquid level height.

The calculation formula is Ρ=ρ.g.H+Po.

In the formula P is the pressure on the liquid surface of the sensor;
ρ is the density of the liquid to be measured;
g is the local acceleration of gravity;
Po is the atmospheric pressure on the liquid surface;
And H is the depth at which the sensor drops into the liquid.

Extended reading: How to convert a 4-20mA to 0-10V /1-5V signal?

industrial water level sensor advantages and disadvantages

At present, the Submersible Water Level Sensor is the most used one.

Submersible Water level transducers generally use the piezoresistive effect of diffused silicon or ceramic sensing elements. Convert static pressure into electrical signal. Temperature compensated and linearity corrected. Converted to 4-20mADC standard current signal output.

The Submersible Water level transducer is directly put into the liquid, and the transmitter part can be fixed by flange or bracket, which is extremely convenient to install and use.
​​
The benefits of water level sensors

• Good stability and high precision;
• The Submersible Water Level Sensor is put directly into the measured medium. It is very convenient to install and use;
• Input type, straight rod type, flange type, threaded type, inductive type, screw-in type, floating ball structure design. Anti-blocking design is available.
• Simple installation, convenient use and strong interchangeability. High-quality level gauges have high sensitivity.
• The response speed is fast, and it accurately reflects the subtle changes of flowing or static liquid level.
• High measurement accuracy.
• Solid-state structure, no moving parts, high reliability.
• Long service life High-precision measurements are possible from water and oil to more viscous pastes.
• A wide range of temperature compensation is not affected by the foaming, deposition, and electrical properties of the measured medium.
• The Submersible Water Level Sensor has power reverse polarity protection and overload current limiting protection.

The disadvantages of Submersible Water Level Sensor are:

• The measurement signal needs to be converted;
• Cannot measure the temperature of high temperature medium over 125℃;
• The density of the measuring medium must be uniform.

These points also limit its scope of use. But for water level measurement, Submersible Water Level Sensor is the perfect choice.

Extended Reading: 3 inch (3″) Water Meter

water level sensor applications

Uses of water level sensors include the following applications:

• Water level measurement in pools and tanks
• River and lake water level measurement
• Marine level measurement
• Level measurement of acid and alkali liquids
• Oil level measurement of oil trucks and mailboxes
• Swimming pool water level control
• Tsunami Warning and Sea Level Monitoring
• Cooling tower water level control
• Sewage pump level control
• Liquid level remote monitoring

Extended reading: Sludge Blanket Level Detector Appliactions

digital water level recorder

Paperless Recorder is an intelligent Digital chart recorder. Data can be remotely recorded, analyzed, stored, and signal output. LCD color screen, maximum 16 channels.

R7100 series color paperless recorder supports 1-16 channels of universal input. R7100 has a powerful display function, real-time curve display, historical curve recall, bar graph display, alarm list display, power-down list display.

Configurable and optional inputs: standard voltage, standard current, thermocouple, thermal resistance, frequency, switch value, pulse, etc. It can be equipped with 6 relay alarm outputs, 6 feed outputs, 4 transmitter outputs, and RS232/485 communication interface is optional. Bluetooth function, GPRS function Ethernet interface, micro printer interface and USB interface.

Sino-Inst offers a variety of digital water level recorder instruments for industrial control. If you have any questions, please contact our sales engineers.

Related Blogs

Sino-Inst offers over 10 Water Level Transducers About 50% of these are submersible liquid level meters, 40% is the others types.

A wide variety of Water Level Transducers for Liquid Level Measurement options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of Water Level Transducers for Liquid Level Measurement instrumentation, located in China.

Request a Quote

Featured Explosion Proof Ultrasonic Level Sensors

Intrinsically Safe/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 about: What Is the Difference Between Class 1 Div 1 and Class 1 Div 2 ?

Two-wire Explosion Proof Ultrasonic Level Sensor

• Measurement range: 5m, 10m, 15m, 25m (selected according to the actual measurement range)
• Blind area: 0.25m～0.8m
• Ranging accuracy: 0.25% to 0.5% (standard conditions)
• Ranging resolution: 1mm
• Pressure: Below 4 atmospheres
• Instrument display: Built-in LCD to display liquid level or space distance
• Analog output: 4～20mA
• Digital output: none
• Power supply voltage: DC24V/1W, built-in lightning protection device
• Ambient temperature: -20℃～+60℃ High temperature needs to be customized (customizable temperature resistance 90℃)
• Protection class: IP65 or IP68

Extended reading: Case Study: Automatic Sludge Blanket Level Detector

Four-wire Explosion Proof Ultrasonic Level Sensor

• Measurement range: 5m, 10m, 15m, 25m (selected according to the actual measurement range)
• Blind area: 0.25m～0.8m
• Ranging accuracy: 0.25% to 0.5% (standard conditions)
• Ranging resolution: 1mm
• Pressure: Below 4 atmospheres
• Instrument display: Built-in LCD to display liquid level or space distance
• Analog output: 4～20mA
• Digital output: RS485, Modbus protocol or custom protocol
• Relay output: two independent outputs
• Power supply voltage: DC24V/AC220V, built-in lightning protection device
• Ambient temperature: -20℃～+60℃ High temperature needs to be customized (customizable temperature resistance 90℃)
• Protection class: IP65 or IP68

More about Factors To Consider When Choosing Explosion Proof Ultrasonic Level Sensors.

External Explosion Proof Ultrasonic Level Sensor

• Range specifications optional: 3m, 5m, 10m, 20m, 30m
• Display resolution: 1mm
• Short time repeatability: 1mm
• Measurement error: ±1‰FS (too thick tank wall, unstable pressure and temperature may affect the accuracy)
• Migration amount: ±10 m
• Current output: 4～20mA, maximum load 750Ω
• Communication: RS-485, infrared interface
• The ambient temperature of the liquid level gauge host: -30℃～+70℃
• Ultrasonic probe using ambient temperature: -50℃～+100℃, (wide temperature probe can be provided according to customer needs)
• Operating environment humidity: 15%～100%RH
• Explosion-proof mark: Ex d IIC T6 Gb
• Shell protection: IP67
• Liquid level display: 6-digit OLED display (unit: m)
• Blind zone: There is a measurement blind zone in the ultrasonic level gauge

Extended reading: Non contact level measurement

Ultrasonic Level Sensor Working Principle

The working principle of the ultrasonic liquid level sensor is:

Ultrasonic transducer (probe) emits high-frequency pulse sound waves, and the surface of the measured level (material) is reflected back. The reflected echo is received by the transducer and converted into an electrical signal. The propagation time of the sound wave is proportional to the distance from the sound wave to the surface of the object.

The relationship between the sound wave transmission distance S and the sound speed C and the sound transmission time T can be expressed by the formula: S=C×T/2.

The probe part emits ultrasonic waves, which are then reflected by the liquid surface. The probe part is received again. The distance from the probe to the liquid (object) surface is proportional to the elapsed time of the ultrasonic wave:
hb = CT2
Distance [m] = time × speed of sound/2 [m]
The temperature compensation formula of sound velocity:
Ambient sound velocity = 331.5 + 0.6 × temperature

Extended reading: Amazing Solutions for Continuous Liquid Level Measurement

Ultrasonic Level Sensor for Tanks

Ultrasonic fuel tank level sensor, also called non-contact fuel meter. Ultrasonic level sensor measure continuous liquid level, fluid level, or oil level.

Ultrasonic level sensors measure the distance between the transducer and the surface. Using the time required for an ultrasound pulse to travel from a transducer to the fluid surface and back (TOF).  These sensors use frequencies in the tens of kilohertz range; transit times are ~6 ms/m.  The speed of sound (340 m/s in air at 15 degrees C, 1115 fps at 60 degrees F) depends on the mixture of gases in the headspace and their temperature.

More about Ultrasonic level measurement

Ultrasonic sensors work without the need to touch the medium being measured. Ultrasonic sensors are ideal for difficult or corrosive liquids such as acids, wastewater, and others. Ultrasonic level sensors are also ideal for continuous level measurement. While float switches and other sensors are adept at measuring when liquid levels are above or below a certain point. The nature of ultrasonic level measurement is such that levels can be sensed and displayed in real-time.

Read more about: Top 5 Ultrasonic Level Sensor Applications

Features of Ultrasonic Tank Level Sensor：

• Non-contact – nothing touches the liquid
• Easy to install at the top of the tank into standard fittings
• Use indoors or outside, in metal or plastic tanks
• Connects to other industrial equipment
• Measures a wide variety of liquids and liquid environments
• Accessories to display, alarm, and control liquid levels
• Wireless option sends tank levels to a LAN or the cloud
• MRO & OEM tank setup duplication without re-calibration

Read more about: Ultrasonic Tank Level Sensor-External Mounted

More Explosion Proof Transmitters

Related Blogs

Sino-Ins offers 20 Explosion Proof Ultrasonic Level Sensors products.

About 13% of these are ultrasonic level transducers, 4% are ultrasonic level indicators.

A wide variety of Explosion Proof Ultrasonic Level Sensor options is available to you, such as free samples, paid samples.

Sino-Inst is an Explosion Proof Ultrasonic Level Sensor supplier, located in China.

Explosion Proof Ultrasonic Level Sensor products are most popular in North America, Mid East, and Eastern Europe.

The United States, and India, which export 99%, 1%, and 1% of ultrasonic level transmitters respectively.

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

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Featured External Tank Level Indicators for Sale

Difficulties Existing in Liquid Level Measurement in Industrial Storage Tank Industry

Most liquid fuels used in industry, such as liquefied petroleum gas, gasoline, diesel, lubricating oil and other refined oils, as well as liquid chemical gases. For example: liquid ammonia, liquid chlorine, are stored in a high-pressure airtight container. In the production process, in order to ensure the safety of production, it is necessary to regularly measure the liquid level of the remaining liquid in the closed container.

Because these liquids are flammable and explosive. Using the traditional liquid level measurement method will cause damage to the tightness of the container. Safety accidents such as liquid leakage are prone to occur. In particular, after the storage tank has been built and put into service. It is hoped that another principle that is different from the existing level gauge will be added, and a level gauge with a different principle will be used. It’s hard for businesses to choose.

Extended reading: What is a capacitive liquid level sensor?

No holes – No damage the tank – External Tank Level Indicator

In response to the above problems, we designed and produced a new type of non-intrusive ultrasonic liquid level measurement system – externally attached liquid level gauge. This enables a truly non-invasive, non-contact measurement method.

Simply mount the measuring probe on the outer wall of the tank or container bottom. The reflection and transmission properties of ultrasonic waves are utilized. Realize the measurement of the liquid level inside the storage tank. The calculated liquid level value is displayed locally and a remote signal is output.

The meter can output measurement results to the control system via 4-20 mA analog signal, HART, RS-485 and other interfaces. At the same time, the data can also be sent to the Internet through wireless transmission via WIFI, GPRS and NBIOT.

Extended reading: Diesel Tank Level Monitoring System

External Tank Level Indicator Applications

External Tank Level Indicator has a wide range of applications. Especially the liquid level measurement application of flammable, explosive, strong corrosive, toxic and harmful pressure vessel storage tanks is more prominent.

Medium:
Liquid chlorine, liquefied gas, liquid ammonia, hydrofluoric acid, propylene, vinyl chloride, ethylene oil, butane, chlorosilane, butadiene, C5, C4, ethylene oxide, butylene oil, silicon tetrachloride, refrigerant , liquid Australia, xylene, hydrochloric acid, nitric acid, lye, isopropanol, ethylene glycol, other media.

Industry :
Chlor-alkali, storage and transportation, petrochemical, refrigeration, coal chemical industry, oil refining, chlorination industry, fertilizer, pesticide, electric power, military, oil depot, liquid storage, and other industries.

Extended reading: level sensors for fuel tanks

Externally Attached Ultrasonic Oil Level Sensor – Trucks

Ultrasonic oil level sensor is an external sensor used to measure the liquid level height in tanks and containers.
The sensor uses the ultrasonic detection principle to measure the oil level（liquid level）, and then converts the measured height value into the oil volume value through intelligent processing, and then transmits the fuel volume data to the background supervision system through GPS to achieve the purpose of real-time monitoring of vehicle fuel consumption.

At present, the products are mainly used in the field of the Internet of Vehicles to monitor the changes in the internal oil level of the tank in real time, so as to realize the detection of fuel volume. It can be used to prevent oil theft, optimize operating costs, optimize driver driving behavior, assist statistical decision-making, etc. At the same time, this product can also be used in fields such as chemical industry, water conservancy, storage tanks and other fields with liquid level detection needs.

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

Related Blogs

Read more about: Common River Water Level Measurement Methods

Sino-Inst offers over 10 External Tank Level Indicators and transmitters for level measurement. About 50% of these are ultrasonic liquid level meters, 40% is the level switches.

A wide variety of External Tank Level Indicators and transmitters options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of External Tank Level Indicators and transmitters instrumentation, located in China.

Request a Quote

Unique Technical Advantages of 80GHZ Radar Level Transmitter

80GHZ Radar Level Transmitter refers to frequency modulated continuous wave (FMCW) radar products operating at 76-81GHz. Four-wire and two-wire applications are supported. There are multiple models, the maximum range of the product can reach 120m, and the blind area can reach 8 cm.

Because the 80GHZ Radar Level Transmitter operates at a higher frequency. shorter wavelengths. So it is especially suitable for solid applications. The working method of transmitting and receiving electromagnetic waves through a lens. It has unique advantages in high dust and harsh temperature environment (+200℃).

80GHZ Radar Level Transmitter provides flange or threaded fixing, which makes installation convenient and easy.

The main advantages of 80GHZ Radar Level Transmitter are as follows:

• Based on self-developed CMOS millimeter-wave radio frequency chip. Enables a more compact RF architecture. Higher signal-to-noise ratio, smaller dead zone.
• The 5GHz operating bandwidth enables the product to have higher measurement resolution and measurement accuracy.
• The narrowest 3° antenna beam angle. Disturbances in the installation environment have less impact on the meter. Installation is more convenient.
• Shorter wavelengths and better reflection properties on solid surfaces. Therefore, there is no need for special use of universal flanges for aiming.
• Support remote debugging and remote upgrade. Reduce waiting time. Improve work efficiency.
• Support mobile phone Bluetooth debugging. It is convenient for on-site personnel to maintain work.

Extended reading: Non contact level measurement

Communication and debugging

The instrument can be debugged through the LCD in the field. It can also be debugged on the PC side with the optional host computer software.

The communication between the 80GHZ Radar Level Transmitter and the PC is as follows:

80GHZ Radar Level Transmitter Measurement Principle

The general principle of the FM continuous wave radar level gauge is that the radar emits electromagnetic waves on the top of the tank. And the electromagnetic waves are received by the radar after being reflected by the medium.

The frequency difference δf between the received signal and the transmitted signal is proportional to the distance R from the surface of the medium:

R=C (speed)*δf (frequency difference)/2/K (frequency modulation slope).

Because the speed of light C and the frequency modulation slope K are known.

The frequency difference δf can be estimated to obtain the distance R from the radar installation position to the material surface.

And then through the known total height of the tank. Subtract the spatial distance from the radar to the material surface (referred to as Empty height) to get the height of the material level.

Extended reading: Magnetostrictive Level Transmitter Working Principle

Terminology

Beam angle:
Beamwidth bounded by 3dB below the maximum value. The minimum beam angle of 80GHZ Radar Level Transmitter is 3°, as shown in the figure.

Distance Resolution:
Range resolution refers to the radar’s ability to distinguish between two objects that are very close together.

If the separation between the two objects is less than the range resolution of the level radar. Then the radar can only measure one distance value. This distance value is not equal to the distance value of any of the objects. It is a combination of the distance values ​​of the two objects.

The FM bandwidth of the 80GHZ Radar Level Transmitter is B=5.1GHz. Minimum distance resolution=C/2B≈3cm.

Measurement accuracy (Accuracy):
If there is only one object and this object has moved a small distance. Whether the level radar can detect distance changes. The indicator of how far a single object has moved is called accuracy.

The IF signal of the 80GHZ Radar Level Transmitter is analyzed by its own algorithm, and the measurement accuracy is 0.1mm.

Ambient temperature:
The temperature of the surrounding air in contact with the device enclosure.

Blind spot:
Refers to the measurement limit of the near end of the instrument, and the instrument cannot measure in the blind area.

dB (decibel):
Indicates the unit of signal amplitude.

Dielectric Constant (DK):
The ability of a dielectric to store electrical energy under the induction of an electromagnetic field. Often referred to as the relative permittivity.

The increase in the permittivity is directly proportional to the increase in the echo amplitude. The relative vacuum/dry air dielectric constant is 1.

Echo:
The reflected signal received by the radar.

Emission cone:
The extension of the antenna beam angle.

False echo:
Any echoes that are not generated by the desired target. Generally, false echoes are generated by obstructions in the container.

Multiple echoes:
The multiple reflection echoes appearing at the target echo distance may be 2 or 3 times.

Polarization:
Emitted electromagnetic wave properties, describing the direction and magnitude of the electric field vector that changes over time.

Range:
(1) Refers to the farthest measurement limit of the instrument
(2) Special, refers to the artificially set maximum distance. Outside this distance, the meter does not consider it when processing data.

Repeatability:
In the same test environment, measure the same reflective target multiple times to measure the deviation of the results.

Speed ​​of light:
Symbol C, the speed of electromagnetic waves. Includes electromagnetic waves and light in free space. The speed of light is 299,792,458 meters per second.

Threshold curve:
A time-varying curve that serves as a threshold beyond which echoes are considered valid.

Extended reading: Amazing Solutions for Continuous Liquid Level Measurement

Beam Angle

The beam angle is the beam angle when the radar wave energy density reaches half of its maximum value (3dB width). Microwaves emit signals outside the beam range and can be reflected by interference objects.

Lens antenna diameter	Φ32mmLens antenna	Φ42mmLens antenna	Φ78mmLens antenna
Beam angle	8°	6°	3°

The larger the antenna size, the smaller the beam Angle alpha, the less the interference echo will be generated.

For more accurate measurements, avoid installing any internal devices (such as limit switches, temperature sensors, bases, vacuum rings, heating coils, baffles, etc.) within the signal beam range.

Linear

Extended Reading: What is level transmitter working principle?

80GHZ Radar Level Transmitter Applications

80G high frequency radar level meter has the characteristics of high measurement accuracy, wide application range, non-contact measurement, etc. It can be widely used in material level and liquid level measurement of various highly corrosive and high dust media.

The 80GHz radar level meter can not only measure the liquid level, but also measure the solid material level. Including powder materials. It has a good application in different storage tanks. Process storage tanks (silo), reaction tanks, static storage tanks , Dome tank, flat-top tank, spherical tank, horizontal tank, stilling pipe, bypass pipe, tank with agitator.

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

Extended reading: Hydrostatic Level Measurement

More Featured Non-Contacting Radar Level Measurement

Read More about: List of Differences: Radar vs Ultrasonic Level Measurement

Related Blogs

Sino-Inst offers 80GHZ Radar Level Transmitters for level measurement.

A wide variety of 80GHZ Radar Level Transmitters options are available to you, such as free samples, paid samples.

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

Request a Quote