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 of solids such as powder, dust, pellets, granules, etc., which are pneumatically conveyed or in free fall (1nm-20mm). Solid flow meters are also called solid powder flow meters, intelligent electrostatic powder flow meters, solid dust flow meters, coal powder flow meters, mineral powder flow meters, lime flow meters, cement flow meters, flour flow meters, petroleum coke powder flow meters.

Solid Flow Meter

Sino-Inst supplies GTL/C powder flow meter. The intelligent electrostatic powder flow meter continuously measures bulk solid materials in a process. The ring sensor is used. It is suitable for the measurement of solid mass flow in a wide range of metal-enclosed pipelines from kgh to th. The system is suitable for online monitoring of solid flow such as powder and dust conveyed by pipeline pneumatic conveying. Also known as pipeline solid flowmeter, solid powder flowmeter, intelligent electrostatic powder flowmeter, solid dust flowmeter, microwave solid flowmeter, etc. Applicable to: coal powder, mineral powder, lime, cement, flour, petroleum coke powder, etc.

Solid Flow Meter Parameters

Pipeline gas pressure-0.1Mpa~2 Mpa
Pipeline gas flow rate1m/s~30 m/s
Pipeline gas temperature-50℃~260℃ (450℃ high temperature customized)
Outer diameter of pipe10mm~600mm
(Standard 5, 10, 15, 20, 25, 32, 40, 50, 65, 80, 100, 125, 150, 200, etc., special specifications can be customized)
Accuracy class±5% of full scale
Measuring range0-20/100/500/2000Kg/h (10kg measuring range customized)
Dust size0.1uM~200 uM
Sensor structureUnobstructed pipeline
Operating environment electromagnetic fieldHigh value at 50 Hz = 60A/m
Operating environment humidityNo condensation 90%
temperaturePTFE lining: -20+120℃
High temperature type PTFE lining -20-+260℃C
Operating environment vibrationHigh continuous oscillation, any direction, any frequency: root mean square value 2g (20m/s2)
Operational environmental protectionProtection grade: IP66/NEMA4 aluminum alloy shell
Transmitter power supply24V (available in the range of 15V~32V)
Transmitter output4~20mA isolated output
Response time1 second
Power consumptionBig 3W
Zero driftLess than 1%
Full scale driftLess than 1%

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

Solid Flow Meter Working Principle

The Solid Flow Meter is based on the theory of contact electrification of solid materials.

The powder will accumulate a certain degree of electric charge during the pneumatic conveying process. This phenomenon is caused by the continuous collision, friction, and separation process between the powder particles and the particles, and between the particles and the tube wall.

The sensor part of the Solid Flow Meter is composed of a short stainless steel tube, a ring electrode, and an insulating layer. The two ends of the short tube are connected to the pipeline through a flange. The grounded metal tube wall plays an electromagnetic shielding role.

When the charged particles pass through the measuring pipe section, based on electrostatic induction, the sensor senses the charge number of the charged particles. The front-end circuit is connected to the sensor and the signal is amplified. Then it is calculated and processed by a converter with a high-speed central processing unit core. The flow rate is calculated and processed. The signal is converted into a standard current signal linearly related to the powder flow rate. It is used for flow control and adjustment.

Extended reading: Stainless steel flow meters|304-316 optional

Solid Flow Meter Features

  1. Suitable for the conveying process of pneumatic conveying device;
  2. Intelligent design, can measure almost all solid materials;
  3. Integrated design, sensor, transmitter and display are integrated;
  4. No throttling parts, no pressure loss during measurement;
  5. Non-contact measurement, not affected by temperature, pressure, and vibration.

Solid Flow Meter Advantages

  1. Advanced toroidal charge sensor has the advantages of fast response, high sensitivity and accurate measurement;
  2. The measurement speed is very fast and the static repeatability is good;
  3. Static particles such as sediments have no effect on the work of the product;
  4. The stainless steel shell is firm and durable, and the PTFE lining is resistant to high temperature and pressure;
  5. Easy installation and maintenance-free.

Solid Flow Meter Application

  1. Power plant boiler coal injection, pulverized coal quality, concentration, flow measurement;
  2. Activated carbon flow detection of waste incineration power generation in power plants;
  3. Limestone powder flow measurement during pneumatic conveying;
  4. Sodium phosphate flow monitoring;
  5. Blast furnace coal injection flow detection.

Application industry:
Chemical, chemical fiber, glass manufacturing plants, food, papermaking, mining and metallurgy, environmental protection, steel, power stations, petroleum, cement manufacturing, and other industrial fields.
It is used to measure the volumetric flow of various small particles such as coal powder, mineral powder, lime, cement, flour, petroleum coke powder. etc.

Read More about Chemical Flow Meter Guide

How Do You Measure the Flow of Solids?

The Solid Flow Meter is based on the theory of contact electrification of solid materials. The powder material will accumulate a certain degree of electric charge during the process of pneumatic conveying or free fall.

Solid Flow Meter uses today’s advanced ring sensor. It can effectively capture every charged powder particle signal that passes through the ring sensor. It is amplified, shaped, and filtered by an amplifier circuit, and then processed by a high-speed processor. The final output is linear with the powder flow The standard current signal of the relationship.

The GTL/C powder flow meter is suitable for the measurement of solid mass flow in metal-enclosed pipelines with a wide range from kg/h to t/h. The system is suitable for online monitoring of the flow of solids such as powder and dust conveyed by pneumatic conveying. It can be widely used in electric power, metallurgy, cement, pharmaceutical, chemical, food manufacturing, and other industries.

Solid Flow Meter Selection Guide

When looking for a solid flow meter suitable for your process, Sino-Inst recommends that you make the best choice based on the following conditions:

  • Maximum flow
  • Material particle size
  • Material temperature
  • Bulk density/bulk density

After finding a solid flow meter suitable for your process according to the application conditions and material characteristics, you should also consider the following influencing factors:

  • Wear: Wear will affect the life of the measuring piece. It is worth noting that changes in material flow will also cause significant wear.
  • Adhesion: Materials should not adhere or accumulate on the surface of the measuring piece, as this will cause calibration deviations due to the buffering effect of adhered or accumulated materials.
  • Corrosive: Corrosive materials will damage the flowmeter components. Corrosive gases are also worth noting.
  • Airflow: Unstable and unpredictable airflow will affect the accuracy of airflow.
  • Unsteady material flow: For uneven material flow, please choose a displacement sensor type solid flowmeter. Because the displacement sensor type solid flowmeter has the characteristics of mechanical hydraulic buffering.

Selection of the capacity of solid flowmeter draft tube:

Sino-Inst prompts you to select the diameter of the draft tube. Regardless of any angle, the material must not exceed 1/2 the filling height of the draft tube.

Extended reading: GWR Solid Level Sensor-for Cement silo-Ash powder measure

Impact Plate Solid Flow Meter

Impact Plate Solid Flow Meter is used for metering equipment for powdery and granular materials with strong fluidity. Mainly suitable for closed material flow. Installation is restricted. Other occasions where similar products cannot be adapted. It is widely used in building materials, cement, chemical industry, coal, mining, ceramics, glass, metallurgy, grain, fertilizer, feed, port, electric power, coking, environmental protection and other industries.

  1. All-steel frame structure, with sufficient rigidity and strength.
  2. The special measuring chute is used to ensure wear resistance, non-sticking of materials, and measurement accuracy
  3. Adopting high-precision digital weighing module, digital transmission technology, with simple circuit, no adjustment and section parts, high resolution, no signal attenuation, and strong anti-interference.
  4. The controller adopts touch display technology, Chinese and English graphical display, guided operation mode, simple operation, no need to remember.
  5. It can be connected to 485 communication, CAN communication, DCS, PLC and other interfaces.
  6. GPRS wireless data transmission function is adopted, which can provide functions such as short message report, remote diagnosis, and scale calibration.

  1. Measuring accuracy: ≤±1%
  2. Feeding capacity: 2-1000T/H
  3. Power supply: 220V/AC±15%, 50Hz±2%
  4. Use environment:
    Scale body: –45~60℃
    Control cabinet: 0℃~45℃
  5. Relative humidity: ≤90%

The solid flow meter sends the measured material flow signal to the microprocessor control system. Automatically calculate the instantaneous flow of materials and the cumulative output of materials. The microprocessor controller constantly compares the actual flow with the set flow. And control the position or speed of the pre-feeding device. So as to change the feed-forward quantity of the material. In order to achieve the purpose of constant feeding.

The function of the calibration chamber is to perform irregular calibration on the feeding part. The feeding part is constantly corrected for errors. To ensure the accuracy of feeding.

Flow Meter Selection Guide 101: Find the Perfect Fit for Your Application

Microwave Solid Flowmeter-Gas Powder Explosion-Proof

The microwave solid flow meter uses the latest microwave technology. It is suitable for the measurement of solids in metal pipes.
Online flow measurement. All powder, dust, crumbs, and particulate matter can be measured repeatedly. The measurement range is as small as kilograms per hour and as large as tons per hour.
A microwave solid flowmeter is suitable for online measurement during pneumatic conveying or free fall. Therefore, it is an alternative product of a cost-effective weighing system.
MONITOR level monitor and display can be used on various occasions to detect the flow/non-flow state of powder and solid particles. Choose SFD-2 solid level monitor or SFI solid level display. Mainly based on the output type (relay or analog Quantity) requirements.

The microwave solid flowmeter uses a 24GH high-frequency microwave. Through the coupling of the electromagnetic field between the sensor and the pipeline, a measurement field is generated.
When the detected medium passes through the microwave detection field, the sensor transmits low-power microwaves and receives the energy reflected by the object. There is a frequency difference between the received microwave reflection frequency and the transmission frequency. A low-frequency AC voltage is generated at the output end. That is, the microwave sensor detects the quantity and flow rate of the moving medium.
The microwave energy of the measuring field is reflected by the solid particles and received by the receiver. According to the Doppler principle, only the flowing particles can be measured by the microwave solid flowmeter. The flow rate (mass) can be calculated by combining the number and state of the particles recorded.

  • Non-contact mass flow online measurement
  • Compact structure and no need for armor protection
  • Easy, fast and cost-effective installation and start-up
  • Adjustable sensitivity
  • With RS485-interface can be connected to the system
  • The most advanced microwave technology
  • Robust and durable stainless steel housing
  • Wearable
  • Maintenance-free
  • The following are the main features of the microwave solid flow meter 17-8511-11:
    • Non-plug-in quick installation, no direct contact with the measured medium
    • SFD-2 can provide relay output and convenient electronic remote control
    • SFI solid flow display provides adjustable analog signal
    • Has passed CSA CLASS II, DIVISION I certification for use in hazardous situations

  • Suitable for pneumatic conveying device and free fall conveying process
  • Suitable for all solid materials, ranging from several kg/h to several t/h
  • No need for armor protection inside the tube, internal fittings are flush assembled
  • Non-contact measurement, not affected by temperature, pressure, and vibration
  • Very fast measurement speed, good static repeatability
  • Static particles such as sediments have no effect on this
  • Sensor-transmitter distance up to 2,000 meters
  • Limit alarm monitoring, with alarm contact
  • Highly sensitive type MF3000-S suitable for very small flow
  • MF3000-D suitable for high pressure
  • Suitable for ATEX area type 20 and type 2

  1. Coal injection in iron-making blast furnaces and coal injection in power plant boilers (the instantaneous pulverized coal concentration of the coal injection main pipe and each branch pipeline can be monitored online, and the working status of each tuyere can be judged.
  2. Monitoring of soot emission concentration of various fuel boilers
  3. Widely used in various industrial applications, including: steelmaking, power generation, petroleum, chemical, pharmaceutical, building materials processing, coal mining and mining, cement manufacturing and packaging industries.
  4. It can detect all dusty objects, such as sand, gypsum, wood chips/craft wood chips, cement, coal ye/brown coke powder, flour, calcium carbonate powder, talcum powder, crushed stone, lime powder, limestone powder…

A microwave solid flow meter monitors the blockage of a part of the transportation line or the entire line. Monitors the bridging status of the upstream medium in the storage tank. Monitors the inappropriate or inadequate flow of the medium due to the failure of the upstream equipment. Monitors the flow state of the medium. Control Start/stop of equipment. Control downstream processes.

More Featured Flow Meters:

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Sino-Inst offers over 50 flow meter for flow measurement. About 50% of these are differential pressure flow meters, 40% is the liquid flow sensor, and 20% are Ultrasonic Level Transmitter and mass flow meter.

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

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

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Differential Pressure Flow Meter Calculation Formula and Calculation Examples

Differential pressure flow meters can measure all single-phase fluids. It can measure liquid, gas, and steam. Such as gas-solid, gas-liquid, liquid-solid, etc. can also be applied.

The calculation work in the use and maintenance of the differential pressure flow meter is indispensable for the instrument person. In this article, Sino-Inst shares the commonly used flow calculation formulas and calculation examples of differential pressure flowmeters. Mastering these technologies will have a multiplier effect on the use of differential pressure flow meters.

The differential pressure flow meter consists of a primary device and a secondary device.

The primary device is called the flow measuring element. It is installed in the pipeline of the fluid to be measured. It produces a pressure difference proportional to the flow (velocity). It is used for the secondary device to display the flow.

The secondary device is called a display instrument. It receives the differential pressure signal generated by the measuring element and converts it into the corresponding flow rate for display. The primary device of the differential pressure flow meter is often a throttling device or a dynamic pressure measuring device (pitot tube, velocity tube, etc.).

The secondary device is a variety of mechanical, electronic, and combined differential pressure meters equipped with flow display instruments. The differential pressure-sensitive components of differential pressure meters are mostly elastic components.

Since the differential pressure and the flow have a square root relationship, the flow display instruments are equipped with a square root device to linearize the flow scale.

Most meters are also equipped with flow totalizers to display the cumulative flow for economic accounting. This method of using differential pressure to measure flow has a long history and is relatively mature. Countries around the world are generally used on more important occasions. It accounts for about 70% of various flow measurement methods.

Extended Reading: Differential Pressure (DP) Flow Meters Technology

Extended reading: What Is Flush Diaphragm Pressure Sensor?

The advantages of throttling differential pressure flow meter:

  • The structure is simple, firm, stable, and reliable, long service life, and low price.
  • The measurement accuracy can reach +-1~2%.
  • It can be applied to high temperature and high-pressure occasions.
  • There are large-caliber products.

The throttling differential pressure flow meter makes the fluid lose its ideal state in throttling. The disadvantages are as follows:

  • The narrower 1:3 range ratio is only suitable for the occasions where the steam consumption of heating network users is relatively stable.
  • Longer front and rear straight pipe sections are required for installation to ensure a stable pipe flow at the inlet end of the throttle, which is generally difficult to meet.
  • The pressure loss of the orifice plate and nozzle is large.
  • There are too many factors that affect the measurement accuracy, from design, manufacturing to installation, the requirements are strict. Any link that does not meet the requirements of the standard documents will bring about greater measurement errors.

The biggest disadvantage of the throttling flow meter is that it requires a long straight pipe section to obtain higher accuracy, and it has greater limitations in practical applications.

Extended reading: Featured Diaphragm Seal Pressure Transmitters

Featured Differential Pressure Flow Meters

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

Differential pressure flow meter calculation

Calculation formula 1: Conversion of differential pressure and flow rate of differential pressure flow meter

The differential pressure of a differential pressure flow meter is proportional to the square of the flow, or the flow is proportional to the square root of the differential pressure. Expressed by the following formula:

The scale unit of the flow meter is the flow percentage, and when the lower limit range of the differential pressure is 0, we get:

In the above formula:
△P is any differential pressure;
Q is any flow;
△Pmax is the upper limit of differential pressure;
Qmax is the upper limit of flow;
n is any percentage of flow

Extended reading: Measuring Flow With Pressure Sensors

[Calculation example 1]

The range of a certain differential pressure transmitter is 0-40kPa. The corresponding flow rate is 0-1603/h. The output signal is 4-20mA. What is the flow rate when the output current of the differential pressure transmitter is 8mA? What is the differential pressure?


①Calculate the flow rate of the differential pressure flow meter according to the flow calculation formula

When the output is 8mA, the flow rate is 80m3/h.

②When the differential pressure transmitter is known to output 8mA. The flow rate is 80m3/h. The flow rate is 50% of full scale. Calculate the differential pressure value of the differential pressure transmitter according to the flow calculation formula

When the output current is 8mA, the differential pressure is 10kPa.

Extended reading: Industrial Pressure Transmitters|Buy from the manufacturer

Calculation formula 2: Conversion of volume flow in standard state and working state

The conversion formula of volume flow between standard state and working state is as follows:

In the formula,

qv is the volumetric flow rate under working conditions, in m3/h;
qn is the volume flow under standard conditions, in m3/h;
P is the absolute pressure under working conditions, the unit is Pa;
Pn is the absolute pressure in the standard state, in Pa;
T is the thermodynamic temperature under working conditions, in K;
Tn is the thermodynamic temperature in the standard state, in K;
Z is the gas compression coefficient under working conditions;
Zn is the gas compressibility coefficient under standard conditions;

Extended reading: how to calibrate a pressure transmitter

[Calculation example 2]

The design range of an airflow meter is 0-2000m3/h (at 20℃, 101.325kPa state). The pressure under working conditions is 0.5MPa. The temperature is 60°C. Find the volume flow under working conditions.

Solution: Substitute the data into the formula to calculate the volume flow under working conditions

The volume flow range of this flow meter is 0-460m3/h under working conditions.

Extended reading: Vortex Steam Flow Meter

Calculation formula 3: Calculation of changing range of standard orifice plate

Sometimes it is encountered in the field that the measured flow exceeds the maximum range of the orifice plate, or the flow is too small and can only be displayed below 30% of the maximum range. The emergency can be met by expanding or reducing the differential pressure range. The basis for changing the range is the formula. The maximum differential pressure and maximum flow rate of the flow meter in use are known. With these two parameters combined with the flow calculation formula, the calculation work for changing the range can be carried out.

Extended reading: wireless pressure transmitter working principle

[Calculation example 3]

There is an orifice flow meter, the original design differential pressure range is 0-60kPa. The flow range is 0-10000kg/h. The process flow of the expansion of production scale has exceeded the maximum flow of the orifice, and the range is planned to be expanded to 0-15000kg/h.

Solution: Calculate the corresponding maximum differential pressure according to the formula

The differential pressure value simply calculated above will have a certain error and is not a trade settlement. It can be used in general production sites. Uncertainty will not be a problem, but the pressure loss will increase. When changing the range of the orifice plate, the influence of many parameter changes should be considered comprehensively, and the iterative calculation method should be selected for the formal.

What is the difference between iterative calculation and simple calculation? The following is a comparative example

Extended reading: Liquid Bitumen/Asphalt Flow Meter

[Calculation example 4]

The original maximum flow rate of a certain steam flow meter was 70,000 kg/h, and the maximum differential pressure was 100 kPa. Because the actual flow is too small, the proposed maximum flow is 35000kg/h. The result of iterative calculation by computer is 35000kg/h, and the corresponding maximum differential pressure is 24.837kPa.

Solution: According to the formula, use a simple method to calculate the maximum differential pressure corresponding to 35000kg/h as 25kPa

If the result of the iterative calculation is taken as the standard value, the error of the simple calculation is:

Compared with the two methods, the error generated by the simple calculation method is 0.656%. Many production sites are still acceptable, especially for emergencies. Because the replacement of the orifice plate needs to be ordered and stopped. In order to reduce errors, some parameters (such as outflow coefficient, expansion coefficient, fluid density, etc.) can be indirectly corrected in the flow totalizer or DCS.

Change the range of the standard orifice plate by yourself, and first calculate it according to the flow calculation formula. Then set the range of the differential pressure transmitter according to the calculation result and calibrate it. Set the new parameters of the flow totalizer and DCS, then it can be put into use.

Changing the range of the orifice plate by yourself is restricted by conditions, that is, the newly changed range cannot exceed the 3:1 adjustable range of the standard orifice plate. The iterative calculation method is used when conditions permit. Or redesign the orifice plate.

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

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Sino-Inst, Manufacturer for differential pressure flow meter. Including an Orifice plate, Venturi, Annubar, etc. Suitable for liquid, gas, and steam flow measurement.

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

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Sludge Flow Meter for Return Activated Sludge

A sludge flow meter refers to a flow meter that can be used to measure the flow of sludge.

What kind of flowmeter can be used for sludge flow measurement?

According to the characteristics of the sludge medium, the flow rate of the sludge can be measured by using an electromagnetic flowmeter. The electrode material uses a tantalum electrode. The lining material uses a ceramic material or tetrafluoroethylene. This can solve the flow measurement condition of the sludge.

Sludge treatment (sludge treatment) refers to the reduction, stabilization, and harmless processing of sludge such as thickening, tempering, dewatering, stabilization, drying, or incineration. The higher the degree of sewage treatment, the more sludge residues that need to be treated.

Why use an electromagnetic flowmeter to measure the sludge flow rate?

The main reason for using an electromagnetic flowmeter to solve the flow of sludge is its low cost, high measurement accuracy, and good stability. Many flows measuring instruments can meet this requirement.

Featured Sludge Flow Meters

Read more about: Different Types of Flowmeters – Technical and Application Analysis

Return Activated Sludge

The wastewater treatment plant uses a secondary treatment process called activated sludge. This process converts non-sedimentable substances into biological flocs. This substance is produced in the aeration tank and settled in the final sedimentation tank.

Activated sludge is an aerobic process. It can promote the health of microorganisms and ensure effective treatment. The balance between food and oxygen and microorganisms must be maintained for optimal treatment. An element of maintaining biomass is to return a part of the sedimentation sludge from the final sedimentation tank to the aeration tank to maintain the balance of the biological system. This part of activated sludge is called RAS (Returned Activated Sludge).

The RAS is returned to the aeration tank via a variable-speed centrifugal pump. Accurate flow rate measurement is essential to ensure that the proper ratio of “food to microorganisms” is maintained. The RAS flow rate is determined by a microbiological health laboratory analysis, and the flow rate is adjusted accordingly.

Extended reading: Insertion Ultrasonic Water Flow Meter – Designed for Agricultural Irrigation, Garden Management

Sludge Flow Measurement of Return Activated Sludge Pipe

1 Project background

  • DN 400mm stainless steel pipe;
  • Full tube
  • High pollution load, suspended solids content as high as 1%.

2 Measurement requirements

  • Trouble-free and stable measurement of the horizontal conveying pipe of the return sludge conveyed by the screw pump lifting equipment;
  • Due to high pollution load and gas load. The two existing measurements. Electromagnetic flowmeter + external clamp ultrasonic time difference method. Neither can work reliably or at all;
  • The installation cost is low.

3 Solution

  • Use NFP type cross-correlation flow measurement system;
  • A hole was drilled upstream of the existing electromagnetic flowmeter. The NFP mounting piece was welded to the existing pipeline;
  • Install a ball valve that can remove the sensor during operation, adjust and fix the cross-correlation sensor.

4 Advantages

  • Simple and fast upgrade and transformation of existing facilities;
  • The old flow measurement equipment does not necessarily need to be dismantled;
  • Although the concentration of suspended solids in the water is high, the flow measurement is still reliable.

Read more about: Shop 101: Key Factors In Selecting A Pipe Flow Meter

Extended reading: Micro flow meters for low flow liquids

Advantages of electromagnetic flowmeter in sludge measurement

  1. The electromagnetic flowmeter has no mechanical inertia. Responsive. Can measure instantaneous pulsating flow. It can also measure the flow in both directions.
  2. The output of the electromagnetic flowmeter is only proportional to the average flow rate of the measured medium. It has nothing to do with the flow state (laminar or turbulent) under symmetrical distribution. Therefore, the electromagnetic flowmeter has a very wide range. The measurement range can reach 100:1, and some even reach the operable flow range of 1000:1.
  3. The sensor structure of the electromagnetic flowmeter is simple. There are no moving parts in the measuring tube, nor any throttling parts that hinder fluid flow. So when the fluid passes through the flow meter, it will not cause any additional pressure loss. It is one of the flow meters with low energy consumption in the flowmeter.
  4. The industrial electromagnetic flowmeter has a very wide caliber range. From a few millimeters to a few meters. Moreover, there are real-flow calibration equipment with a diameter of 3m in China. Laid a foundation for the application and development of electromagnetic flowmeters.
  5. The electromagnetic flowmeter is a volume flow measuring instrument. During the measurement process, it is not affected by the temperature, viscosity, density and conductivity (in a certain range) of the measured medium. Therefore, the electromagnetic flowmeter only needs to be calibrated by water. It can be used to measure the flow of other conductive liquids.
  6. It can measure the flow of dirty medium, corrosive medium and suspended liquid-solid two-phase flow. This is because there are no obstructing flow parts inside the meter measuring tube. The fluid to be measured is only in contact with the inner lining of the measuring tube and the electrode, and the material can be selected according to the nature of the fluid to be measured.

For example, use polytrifluoroethylene or polytetrafluoroethylene as the lining. It can measure various corrosive media such as acid, alkali and salt. The use of wear-resistant rubber as the inner lining is particularly suitable for measuring liquid-solid two-phase flows such as mineral slurry and cement slurry with solid particles and greater wear, as well as various suspended liquids such as fiber-containing liquids and pulps.

Extended reading: Orifice Plate Flow Meter

Can electromagnetic flowmeter measure sludge fluid with 85% moisture content?

Yes, there is no problem at all. I am the technology of the electromagnetic flowmeter manufacturer, and the measurement is no problem. It is only when the density of the sediment particles reaches a certain level. There will be peak fluctuations. However, the measurement is no problem.

Extended reading: ultrasonic sludge level meter

Which lining material electromagnetic flowmeter is used for sludge flow meter?

What kind of flowmeter can be used for sludge flow measurement. According to the characteristics of the sludge medium, the flow rate of the sludge can be measured by using an electromagnetic flowmeter. The electrode material uses tantalum electrode, and the lining material uses ceramic material or tetrafluoroethylene. In this way, the sludge flow measurement conditions can be solved.

More about:

Learn More about Sludge Treatment

Before sludge treatment, we must first understand the classification of sludge:

  1. Treatment of physicochemical sludge discharged from sedimentation tank or thickening tank of waterworks. It is a medium and fine-grained organic and inorganic mixed sludge. The compressibility and dehydration performance are average.
  2. The remaining activated sludge discharged from the secondary settling tank of the domestic sewage plant is hydrophilic, fine-grained organic sludge, with poor compressibility and poor dehydration performance.
  3. Treatment of physicochemical and biochemical mixed sludge discharged from the thickening tank produced by industrial wastewater treatment. It is a medium-fine-grained mixed sludge. The dewatering performance of the fiber-containing body is better. The other compressibility and dewatering performance are average.
  4. The physical and chemical fine-grained sludge produced by the physical method and chemical method discharged from the thickening tank from the industrial wastewater treatment. It belongs to the fine-grained inorganic sludge. The compressibility and dewatering performance are general.
  5. Physical and chemical precipitation of coarse-grained sludge produced by industrial wastewater treatment. It belongs to coarse-grained hydrophobic inorganic sludge. It has good compressibility and dewatering performance.

Extended reading: Stainless steel flow meters|304-316 optional

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Sino-Inst offers Sludge flow meter products. About 85% of these are Magnetic flow meters, 3% are Ultrasonic water meters. A wide variety of Sludge flow meter options are available to you, such as free samples, paid samples.

The top-selling countries or regions are China, India, and Israel, which supply 99%, 1%, and 1% of sewage flow meter respectively. Sludge flow meter products are most popular in Domestic Market, Mid East, and North America. You can ensure product safety by selecting from certified suppliers, with ISO9001, and Other certifications.

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

4-20mA to 0-10v voltage, this is I/V conversion. That is current-voltage conversion, usually used for long-distance signal transmission in the industry.

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

There are two methods: one is to do it yourself with an operational amplifier. The other is to buy ready-made products, such as a 4-20MA/0-10V current-to-voltage isolation converter.

4-20mA is the standard output of our measuring instrument. Such as pressure transmitter, temperature transmitter, flow meter, liquid level transmitter, and so on.

In the field of industrial measurement and control, we often encounter the following problems:

How to convert 0-5V to 4-20mA, 0-20mA or 4-24mA?

How to convert 0-10V to 4-20mA, 0-20mA or 4-24mA?

How to transform ±5V, ±10V AC voltage signal into 4-20mA, 0-20mA, or 4-24mA DC current signal?

4-20mA means that the minimum current is 4mA and the maximum current is 20mA.

The industry generally needs to measure various non-electrical physical quantities, such as temperature, pressure, speed, angle, etc. They all need to be converted into analog electrical signals before they can be transmitted to the control room or display equipment hundreds of meters away. This device that converts physical quantities into electrical signals is called a transmitter. The most widely used in the industry is to use a 4-20mA current to transmit analog quantities.


  • The general input impedance of 4-20mA is 250-300 ohm, which is not easy to have interfered. But maintenance measurement is more troublesome;
  • 4-20ma DC signal can provide power. In addition, it is not affected by the load size within a certain range, and has strong anti-interference ability.
  • 4-20mA can realize two-wire transmission, saving wires.
  • The current signal is suitable for long-distance transmission, but the current signal has weak anti-interference ability, and shielded wires are generally used.


  • 0-10v are generally high-impedance inputs and are susceptible to interference. But maintenance, measurement and calculation are all very convenient.
  • 0-10V, is active, three-wire system, or four-wire system.
  • The voltage signal is stable and anti-interference is strong, but it is not suitable for long-distance transmission (with voltage drop);

The 4~20ma signal is the sensor transmission signal commonly used in industrial transmitters. It does not have a fixed-line voltage. The current is constant during transmission and the voltage changes with the load.

For our measurement and control instruments, it depends on whether your instrument wiring is a four-wire system or a two-wire system.

The four-wire system may be AC220V or DC24V;
Two-wire system or three-wire system, generally DC24V.

Read more about: What Is 0-10V Signal Output?

4-20mA standard signal conversion

Common standard analog signals are: 0-5V, 0-10V, ±5V, ±10V, 4-20mA, 0-20mA or 4-24mA. Common transmitters or sensors use one or more of the above formats to output standard signals.

Common secondary meters or acquisition cards generally accept input signals of one or more of the above formats.

When the output signal of the transmitter or sensor is different from the input signal format of the secondary instrument or acquisition card, we need to add a converter between them.

Because the 4-20mA standard signal has the advantages of strong anti-interference ability and no attenuation in the transmission process, it has been widely used in the field of measurement and control.

Often in order to achieve interface compatibility or improve electromagnetic compatibility, it is necessary to convert 0-5V, 0-10V and other standard voltage signals into 4-20mA standard current signals. Or the 4-20mA current signal needs to be converted into a 0-5V or 0-10V standard voltage signal suitable for the input of the acquisition card.

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

I have a pressure transmitter here that outputs a current of 4-20mA. As the input signal of the inverter. Now it is required to change the input signal of the inverter to a voltage signal. That is, the current of 4-20mA should be replaced with a voltage of 0-5V or 0-10V. The inverter has two inputs: 0-5V and 0-10V. Excuse me, how can it be transformed?

Answer: There are two schemes to achieve:

1.Use a hardware circuit to convert the input 4-20mA current signal into 0-5V or 0-10V voltage signal. See the circuit diagram below:


  1. Select the A input port: connect A+ and RA together, connect an external 4-20mA current input signal, and connect the A- terminal to the PLC common point M. A input port is set to 0~20mA current input mode.
  2. The analog output port uses voltage output port V0, its M0 port is connected to the common terminal M, and the output port is set to voltage output mode: 0~10V (or 0~5V).

2.Use a signal converter

The signal converter converts the DC current or voltage signals of various devices on the site into the required DC signals for isolation and transmission and then outputs them to other instruments. The signal isolator can effectively eliminate ground return. Solve the problems of industrial field interference and signal conversion, transmission, and matching.

It is widely used in data acquisition, signal transmission and conversion, PLC, DCS, and other industrial measurement and control systems in electrical, power, telecommunications, steel, petrochemical, sewage treatment, environmental protection engineering, aerospace, building automation, and other fields. It is used to complete and supplement the system simulation I/O plug-in function. Increase
The applicability of the system and the reliability of the on-site environment.

Main Specifications

  • Measurement: DC current, DC voltage, etc.
  • Accuracy: ≤±0.1% F·S
  • Power consumption: <1W (when 24VDC power supply)
  • Impedance: current input ≤100Ω, voltage input ≥500KΩ
  • Power supply: DC24V, AC220V or customized
  • Isolation: Input, output, and power supply are completely isolated
  • Support live hot swap operation. Easy to unload, high precision, high linearity, strong anti-interference
  • Long-term work stability
Input signalEnter parameter codeOutput 1Output 2Power supply
A DC power supply
V DC voltage
Current Range
A420 4-20mA
A020 0-20mA
A010 0-10mA
T customer self-determined;

Or voltage range
V15 1-5V
V075 0-75mV
T customer self-determined
V010 0-10V
V15 1-5V
T customer self-determined
A420 4-20mA
T customer self-determined
No input
A AC220V
T customer self-determined

No matter which WaterFlow Meters you choose. The signal output by WaterFlow Meters, such as 4-20mA. The flow signal can be connected to a paperless recorder. Carry out multi-channel flow signal monitoring.

Our paperless recorder, also known as Digital Chart Recorder. also has such a function. Support signal input and output. You can configure appropriate functions according to your own needs. What Is A Digital Chart Recorder?

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Sino-Instrument offers a variety of transmitters and sensors that support signal output. Including 4-20mA, 0-10V, 1-5V, etc.

About 30% of these are 4-20ma Pressure Transducers, 30% are Flow Meters, and 20% are Level Transmitters, 20% are 4-20ma Temperature transmitters.

Sino-Instrument is a globally recognized supplier and manufacturer of Pressure Transducers, located in China.

The top supplying country is China (Mainland), which supply 100% of Pressure Transducers respectively.

Sino-Instrument sells through a mature distribution network that reaches all 50 states and 30 countries worldwide.

Low-Pressure Transducers products are most popular in Domestic Market, Southeast Asia, and Mid East.

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

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Laser Level Transmitter

What is a laser level transmitter?

A laser level transmitter is also called a laser level meter. Industrial Accurate, non-contact, and uninterrupted real-time monitoring of material height. Designed for material level and liquid level. A laser level transmitter is a continuous or high-speed pulsed laser beam emitted by a semiconductor laser.

The laser beam meets the surface of the object to be measured and reflects. The light return is received by the laser receiver. And accurately record the time difference between laser emission and reception. In order to determine the distance from the laser radar to the measured object. Laser level transmitter is similar to radar/ultrasonic level sensor.

The laser level transmitter is a non-contact level gauge. The product is powerful, sturdy and durable. It has excellent accuracy and high stability. It achieves accurate, non-contact and uninterrupted real-time monitoring of material height. Industrial site and process, river water level monitoring, material height monitoring and other occasions have very broad applications.

Laser level transmitter Main features:

  • Abundant output interfaces: TTL, RS232, RS485, 4~20mA, CANBUS, ModBus, 0~5V, 0~10V;
  • Ultra-wide power supply voltage: 6~36V DC;
  • The resolution is 0.1mm, and the single acquisition accuracy is better than 1mm;
  • Protection grade: IP67 (anti-salt fog, mildew, anti-collision treatment);
  • Built-in over-current automatic recovery, anti-reverse connection, anti-surge and lightning protection;
  • Non-contact measurement technology, less affected by the working environment, easy to install, layout and back-end control;
  • In an outdoor environment, it can still maintain high measurement accuracy and reliability;
  • The sensor can be processed into a fully sealed, convenient to use in harsh environments;
  • It can be powered by vehicle power supply and industrial DC power supply;
  • Stable power consumption, very low power consumption (when there is no current alarm, the power consumption is less than 1W);
  • Standard industrial bus interface, with operating software to realize all-round industrial automation control;
  • Liquid level and material level height monitoring;
  • It can be equipped with Bluetooth, GPRS, WIFI, rechargeable lithium battery and other functions.

Extended reading: Float Level Sensors – Single and Multipoint

Laser level transmitter data:

Shortest distance0.05m
The longest distance [indoor]10m  20m  40m  80m  200m
Precision±1mm; single measurement accuracy is better than 1mm
Output frequencyUp to 8Hz
laserVisible laser
Laser classClass Ⅱ safety laser
Laser wavelength635nm~650nm
Spot diameter10m@10mm
Laser life>50000h
AnnotationPlease do not stare into the beam, avoid contact with the laser, according to EN60825-1:2003-10 standard
Input voltageDC6-36V
Whole machine power consumption<1W
Digital outputRS485, RS232, TTL, CANBUS, ModBus
Analog output4-20mA, 0~5V, 0~10V
Instrument size80mm*63.4mm*32mm
Shell materialAluminum black anodized
Protection levelIP67
Operating temperature-15℃…+50℃
storage temperature-30℃……+70℃

Laser level transmitter Applications:

Application range:

  • Liquid asphalt, polymerization reactor vessel (high pressure),
  • Reactor vessel (vacuum), molten glass, ferrous and non-ferrous metals,
  • Alloy polystyrene, nylon, polychloride and other core blocks, talcum powder or lime powder,
  • Ore, waste rock in ore chute, wet or dry wood chips;
  • Mining, chemical industry;
  • High-risk areas such as pharmaceuticals, papermaking, plastics, oil and gas, etc.

Restrictions on use: poor accuracy or uselessness under foggy conditions

ElementFactors that extend the measuring rangeFactors that shorten the measuring range
Target surfaceThe brightly reflective surface, such as reflectorDim and matte surface, green and blue surface
Air particlesClean airDust, fog, heavy rain, blizzard
Daylight intensityDark environmentThe target is brightly illuminated
  • Rough surface: When measuring rough surfaces (such as plaster walls), aim at the center of the shiny area.
  • Transparent surface: Please do not measure on the surface of transparent objects, such as colorless liquids (such as water) or glass (no dust).
  • Oblique round surface: The measurement can only be performed when the target area is large enough to accommodate the laser spot.

Extended reading: Hydrostatic Level Measurement

Extended reading: What is Modbus Protocol?

Laser level transmitter working principle

The laser level transmitter adopts the phase method laser ranging technology. Using the frequency of the radio band, the laser beam is amplitude modulated and the phase delay produced by the modulated light going back and forth to the measuring line is measured. Then according to the wavelength of the modulated light, the phase delay represented by this is converted distance. That is, the indirect method is used to measure the time required for the light to pass through the measuring line.

The distance D from the surface of the material is proportional to the time travel T of the pulse:


Where C is the speed of light

Since the distance E of the empty tank is known, the level L is:


According to the range and full scale information set by the user, the processor calculates the percentage of the current material level, and then outputs 4-20mA or 0-5V analog signals, RS485 Modbus digital signals, and warning alarm relay switch signals in proportion.


  • The measuring beam has a small divergence angle and good directivity;
  • Large range, long-distance measurement, minimum blind spot;
  • Not affected by the temperature of the medium;
  • Non-intrusive measurement, non-contact measurement;
  • Fast measurement speed, suitable for fast-changing liquid level and material level measurement;
  • Easy to use, programmable measurement;
  • Accurate measurement and high precision are suitable for high-demand projects;
  • The resolution is ten times higher than the general table;
  • The beam angle is small, suitable for long-distance positioning and avoiding obstacles.


  • Easy to be interfered by the light source in the test band and absorbed by the dark object;
  • Slightly more expensive

Extended reading: Ultrasonic Level Switch-External Mounted

Extended reading: Magnetostrictive Level Transmitter Advantages And Disadvantages

Laser-level measurement has gained popularity in industrial applications. The advantage of laser level measurement is an accurate and simple measurement without contact with the measured material. Even materials with a low dielectric constant can be easily measured with a laser transmitter.

The laser beam is very narrow (divergence <0.3°), and a small spot is formed on the surface, which is usually less than 30cm even at a long distance. The figure below shows a typical installation on the storage bin. The laser transmitter is mounted on the reel using a rotating flange to ensure precise alignment to the bottom of the silo. In order to strengthen the protection, a dustproof tube is also used. For plastic applications, it is important to use metal mounting plates or flanges and ensure that they are properly grounded to the silo to help eliminate static buildup.

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

Extended reading: Radar Level Sensor Advantages and Disadvantages

In order to use water resources rationally, real-time detection of the water level of various water areas is particularly important, so the demand for water level gauges is huge.

The laser level meter is a new type of distance measuring equipment with the advantages of high accuracy, fast response, large range, non-contact measurement, etc. It is suitable for my country’s rivers, lakes, reservoirs, hydraulics, ship locks, rivers, urban water and other liquid level monitoring occasions.

Extended reading: Ultrasonic level transmitter for Hazardous Liquids

Extended reading: Capacitive water level sensor

There are many different ways to measure the level of liquid in a tank, but laser tank level measurement is becoming increasingly popular. This is because laser tank level measurement is more accurate than other methods, and it is also much easier to install and maintain.

Laser tank level measurement works by sending a laser beam across the surface of the liquid in the tank. The laser beam is reflected off the surface of the liquid, and the time it takes for the laser beam to return to the sensor is measured. This time can then be used to calculate the level of the liquid in the tank.

One advantage of laser tank level measurement over other methods is that it is not affected by the temperature or density of the liquid. This means that it can be used to measure the level of liquids with very different properties, such as water and oil.

Another advantage of laser tank level measurement is that it is not affected by the build-up of sediment on the bottom of the tank. This can be a problem with other methods, such as ultrasonic level measurement, which rely on sound waves to measure the level of liquid.

Laser tank level measurement is also much easier to install than other methods. This is because there are no moving parts, and the laser beam can be directed through a small hole in the top of the tank. This means that laser tank level measurement can be used in tanks that are difficult to access, such as those in underground storage facilities.

If you are looking for a reliable and accurate way to measure the level of liquid in a tank, laser tank level measurement is the ideal solution.

Extended Reading: Silo/Bin material level measurement system

Read More About: Ultrasonic tank level bottom sensor

More Featured Liquid Level Sensors and Measurement Solutions

More Featured Solids Level Sensors and Measurement Solutions

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

Laser Level Transmitter is a large-range, high-accuracy explosion-proof level measurement product supplied by Sino-Inst. It has the functions of level measurement, average temperature measurement, switch alarm output, and can be displayed beside the tank. The product structure is reasonable, the precision is high, and the maintenance rate is low.

Laser Level Transmitter can measure media and application methods: particles, lumps, viscosity, water conservancy, distance measurement, liquid level measurement, material level measurement and other working conditions.

Laser Level Transmitter application scale:
Liquid asphalt, polymerization reactor vessel (high pressure), reactor vessel (vacuum), molten glass, black and non-ferrous metals, alloy polystyrene. Pellets such as nylon, polyvinyl chloride, talc or lime powder, ores, waste rock from draw chutes, wet or dry wood chips. Mining, chemical. High-risk areas such as pharmaceuticals, paper, plastics, oil and gas.

Sino-Inst offers over 50 level transmitters for 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.

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Type k thermocouple chart

A thermocouple chart is a practical tool for the electronic query of temperature index. It is used by technicians who are engaged in automatic control of the production process.

To simply look at it means: when 0 is the reference temperature and the measured temperature is the sum of the row and column temperatures, the measured thermoelectric potential is the value.

How do you read a K type thermocouple table?

In the thermocouple chart, the first row and the first column are all temperature values.
The rows are incremented by 10 degrees per grid.
The columns are incremented by 100 degrees per grid.
The intersection of the row and the column is the thermoelectric potential value at the current temperature.

Take the S-type couple to read the thermoelectric potential value at 280 degrees Celsius for example: first find 200 degrees from the first column, and draw a straight line to the right.
Then find 80 degrees from the first line and draw a straight line down. Where the two lines meet, the thermoelectric potential value at 280 degrees is 2.141 millivolts.

Type K thermocouple chart

K Reference terminal temperature: 0℃, 10 degrees μν value



Type N thermocouple chart

N reference terminal temperature: 0℃, 10 degrees μν value









Type E thermocouple chart

E Reference terminal temperature: 0℃, 10 degrees μν value










Type J thermocouple chart

J Reference terminal temperature: 0℃, 10 degrees μν value










Type T thermocouple chart

T reference terminal temperature: 0℃, 10 degrees μν value





Type S thermocouple chart

S Reference terminal temperature: 0℃, 10 degrees μν value


Type R thermocouple chart

R Reference terminal temperature: 0℃, 10 degrees μν value




Type B thermocouple chart

B reference terminal temperature: 0℃, 10 degrees μν value








Download: K thermocouple chart

The working principle of thermocouple (thermocouple principle)

What is a thermocouple?
This is to start with the principle of thermocouple temperature measurement. The thermocouple is a kind of temperature sensing element and a primary instrument. It directly measures temperature and converts the temperature signal into a term electromotive force signal. It is converted into a term electromotive force signal by an electrical instrument (secondary instrument). The temperature of the measured medium.

The basic principle of thermocouple temperature measurement is that two different components of material conductors form a closed loop. When there is a temperature gradient at both ends, there will be a current passing through the loop, and then there is Seebeck electromotive force-term electromotive force between the two ends. This is the so-called Seebeck effect.

Two homogeneous conductors with different compositions are term electrodes, the end with a higher temperature is the working end, and the end with a lower temperature is the free end, which is usually at a certain constant temperature. According to the functional relationship between term electromotive force and temperature, a thermocouple index table is made. The index table is obtained when the free end temperature is at 0℃. Different thermocouples have different index tables.

When the third metal material is connected in the thermocouple circuit, as long as the temperature of the two junctions of the material is the same, the thermoelectric potential generated by the thermocouple will remain unchanged, that is, it will not be affected by the third metal in the circuit. Therefore, when the thermocouple measures the temperature, it can be connected to the measuring instrument, and after the term electromotive force is measured, the temperature of the measured medium can be known.

The working principle of thermocouple:

Two conductors with different components (called thermocouple wires or thermoelectrodes) are connected at both ends to form a loop. When the temperature of the junction is different, an electromotive force will be generated in the loop. This phenomenon is called the thermoelectric effect. And The electromotive force is called thermoelectric force.

Thermocouples use this principle for temperature measurement. One end that is directly used to measure the temperature of the medium is called the working end (also called the measuring end), and the other end is called the cold end (also called the compensation end). The cold end and the display instrument or When the matching instrument is connected, the display instrument will point out the thermoelectric potential generated by the thermocouple.

A thermocouple is actually a kind of energy converter, which converts heat energy into electrical energy. Use the generated thermoelectric potential to measure temperature. Regarding the thermoelectric potential of a thermocouple, you should pay attention to the following issues:

  1. The thermoelectric potential of a thermocouple is a function of the temperature difference between the two ends of the thermocouple. It is not a function of the temperature difference between the two ends of the thermocouple;
  2. The size of the thermoelectric potential generated by the thermocouple. When the material of the thermocouple is uniform, it has nothing to do with the length and diameter of the thermocouple, but is only related to the composition of the thermocouple material and the temperature difference between the two ends;
  3. When the two thermocouple wires of the thermocouple have determined the material composition. The thermoelectric potential of the thermocouple is only related to the temperature difference of the thermocouple. If the temperature of the cold junction of the thermocouple remains constant, the thermoelectric potential of the thermocouple is only Single-valued function of working end temperature.

Sino-Inst, Manufacturer for Thermocouples, like: Armoured thermocouple, assembly thermocouple, explosion-proof thermocouple, etc.

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

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Paddle wheel flow meter technology

What is a Paddle wheel flow meter?

Paddle wheel flow meter is a mechanical flow meter that uses an impeller as a flow sensor component. The impeller-type flow meter is a meter that measures flow according to the principle of fluid momentum moment. Paddle wheel flow meter is also called an impeller flow meter, rotary wheel flow meter, etc. Typical Paddle wheel flow meters are water meters and turbine flow meters. It can be a mechanical transmission output type or an electric pulse output type. It is suitable for the measurement and control of industrial process clean water pipelines or low-concentration acid-base, low-viscosity single-phase fluid non-trade settlement process.

Paddle wheel flow meter Features

  1. Has good anti-interference
  2. Strong signal transmission capability (the farthest transmission is 300 meters)
  3. Stable quality and low failure rate
  4. Superior performance-price ratio
  5. Wide range measurement.
  6. All measurement parameters can be adjusted independently.
  7. Output 4-20mA or RS485 communication output, two pairs of alarm output contacts.
  8. Display real-time flow and cumulative flow.
  9. Insertion installation.

Application range of impeller flowmeter

  • Flow monitoring of industrial water treatment process
  • Industrial circulating cooling water and make-up water flow monitoring
  • Reclaimed water flow monitoring
  • Process flow monitoring after wastewater treatment
  • Agricultural irrigation water flow measurement
  • Multi-way valve and multi-valve system flow monitoring for softening, filtering, etc.
  • Other water flow detection and control

Extended reading: Insertion Ultrasonic Water Flow Meter – Designed for Agricultural Irrigation, Garden Management

Paddle wheel flow meters parameters

ModelKF11 Corrosion-resistant flow sensorKF11 series impeller flow meter
DescriptionSuitable for highly corrosive fluids, sulfuric acid, nitric acid, hydrofluoric acid, hydrochloric acid, mixed acid, strong alkali and other places;
The flow parts are made of corrosion-resistant materials such as PVDF·PTFE·Hastelloy·Titanium alloy; there is almost no pressure loss and maintenance-free;
Flow velocity range 0.3-6m/s, can measure fluid with flow velocity greater than 0.3m/s;
Not applicable to media containing particles and fibrous impurities;
The impeller adopts a five-piece runner design
PP/PVDF/PTFE material
Better guarantee the dynamic balance characteristics, greatly improving the linear accuracy and repeatability accuracy of the sensor;
The minimum flow rate is 0.1m/s; NPN open collector output, which can be directly transmitted to a flow transmitter or PLC, a standard square wave signal and a maximum distance of 300m;
Applicable caliber: DN25-DN600 (1″-24″);
Not suitable for particles and fibrous impurities
The medium;
Caliber rangeDN25-DN600(1″-24″)DN25-DN600(1″-24″)
Flow rate range0.3-5m/s0.1-8m/s
Output signalSquare wave pulse signal: (40-45Hz) nominal flow rate per m/sSquare wave pulse signal: (40-45Hz) nominal flow rate per m/s
Equipped with pulse conversion components can output 4-20mA
CharacteristicHall pulse output, open collector NPN, strong driving ability
Has high chemical resistance
Minimum flow rate 0.3m/s
IP68 protection grade suitable for harsh on-site environment
Hall pulse output, open collector NPN, strong driving ability
Has high chemical resistance
IP68 protection grade suitable for harsh on-site environment
Plug-in type, easy installation, good reliability, almost maintenance-free
Linear accuracy L
Repeatability accuracy R
OntologyPVDF/PTFEPP plus glass fiber/CPVC
Shaft and bearingHastelloy C/Titanium Alloy/ZrO2Al2O3/ZrO2/SS316L/Hastelloy C/Titanium Alloy
O-ringfluororubberFPM/EPDM/Fluorine rubber
Temperature and pressurePVDF body: 12.5bar@25℃-2.5bar@100℃
PTFE body: 12.5bar@25℃-2.5bar@100°
PP body: 12.5bar@25℃-1.7bar@80℃
CPVC body: 12.5bar@25℃-1.7bar@80℃
Power supply systemDC 5-24VDC5-24V
Protection levelIP68IP68
Application fieldSulfuric acid ratio and delivery flow monitoring
Copper sulfate monitoring in electroplating bath
Nitric acid mixture
Chemical waste
Pure Water Process/Reverse Osmosis/Ultrafiltration/EDI
Water purification and filtration system
Cooling water and boiler water monitoring
Chemical industry
Agricultural irrigation
Cleaning system and single crystal silicon cleaning
Pump protection

Check more Choosing The Right 1 Inch Flow Meter.

Paddle wheel flow meter working principle

The sensor is divided into two parts: the transmitter and the impeller. The impeller is in direct contact with the fluid, and the transmitter is isolated from the fluid. The liquid flow drives the impeller to rotate, and there are four evenly distributed magnetic blades on the impeller. The rotating magnetic blade induction Hall switch generates a frequency signal proportional to the flow rate, and the transmitter converts the frequency signal into a 4-20mA current signal.

Typical Paddle wheel flow meters are water meters and turbine flow meters. The structure can be a mechanical transmission output type or an electric pulse output type.

The accuracy of water meters with general mechanical transmission output is low, with an error of about ±2%. However, the structure is simple and the cost is low. It has been mass-produced in China, and is standardized, generalized and serialized. The accuracy of the turbine flowmeter output by the electric pulse signal is relatively high, and the general error is ±0.2%-0.5%

The five-piece impeller design is in line with the principle of fluid mechanics, and the uniform force angle produces a better dynamic balance, ensuring better linear accuracy and repeatability accuracy

Various shafts and bearings:
Shaft and bearing: ZrO2, SS316L, Hastelloy C
Impeller material: PTFE, PP, PVDF, ABS
Body material: PP plus glass fiber, ABS, CPVC, PTFE, SS316L, brass

Real flow calibration
Calibration range: DN10-DN1000
Each sensor has undergone strict calibration and quality inspection. When leaving the factory, each sensor guarantees that the K factor is 2% of the standard value, and the repeatability accuracy is 0.5%;

Read more about: What is an inline flow meter?

Paddle wheel flow meter advantages and disadvantages


  • Excellent reproducibility and responsiveness.
  • Simple structure and low price.
  • Small size, large-capacity measurement is possible.


  • Extremely sensitive to foreign objects. (Causing blockage)
  • Due to the high-speed rotation of the impeller, regular maintenance is required to cope with axial wear or to replace the impeller.

Extended reading: How to Select the Right Agriculture Flow Meter

Paddle wheel flow meter installation

  • The straight section behind the flange must meet the measuring distance of the first 10 and the rear 5 times the pipe diameter;
  • After reducing the diameter (only allowed to change from large to small, but not allowed to change from small to large), the straight line segment needs to meet the measurement distance of the first 15 and the back 5 times the pipe diameter;
  • The straight section behind the first-level equal-diameter elbow needs to meet the measuring distance of the first 20 and 5 times the pipe diameter;
  • The straight section behind the two-stage continuous equal-diameter elbow on the same plane must meet the measurement distance of the first 25 and the rear 5 times the pipe diameter;
  • The straight section behind the non-coplanar two-stage continuous equal-diameter elbow needs to meet the measuring distance of the first 40 and the back 5 times the pipe diameter;
  • The straight section behind the valve must meet the measurement distance of the first 50 and the last 5 times the pipe diameter;
  • The probe is recommended to be installed perpendicular to the pipe, and not at the bottom of the pipe;
  • The probe can be installed on a vertical pipe where the liquid flows upward, but it must also meet the requirements of the above-mentioned straight section;
  • The probe is not allowed to be installed on a vertical pipe where the liquid flows downward;
  • The liquid in the tested pipeline must be full of flow, and no gas and liquid can flow at the same time;
  • The cost of the body must be consistent with the bayonet (open slot) to ensure the correct installation position;
  • The O-ring has a good sealing effect. When the installation is tight, it needs to be wetted with silicone oil or water for installation;
  • The sensor locking cap must be tightened to prevent excessive pressure in the pipeline from leaking or ejecting;
  • When installing outdoors, pay attention to waterproof treatment; keep the cables dry to avoid moisture damage;
  • Do not lay the sensor cable and AC power cable in the same protective tube to avoid electrical interference

Extended reading: Industrial VS Residential inline water flow meters

More Featured Paddlewheel flowmeters

You may like:

Sino-Inst, paddle wheel flow meter manufacturer. It can measure a single sound-conducting liquid medium of Velocity range: 0.1~6m/s; Pipe diameter: DN15 to DN600.

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

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How Does a Piston Flow Meter Work?

What is a piston flow meter?

A piston flow meter is a positive displacement flowmeter, which is mainly used to measure liquid flow. The piston flow meter is composed of a shell, piston mechanism, and other parts. The measured fluid fills a space with a certain volume, and these volume increments are counted and accumulated. It has the advantages of simple structure, reliable work, high accuracy, large range ratio, and little influence on viscosity. It is mostly used for measuring non-corrosive liquids, such as heavy oil or other oils, on small-diameter pipelines.

Piston flow meter technology

Piston-type flowmeters are commonly used for flow measurement of fuel dispensers. Its structure includes a housing, an upper cover, a lower cover, a piston, a crankshaft, and a distribution valve. The inner cavity of the housing is equipped with four-piston cylinders that cooperate with the piston dynamic seal. The four-piston cylinders are evenly distributed in the circumferential direction on the vertical plane of the crankshaft rotation centerline.

The piston is connected to the crankshaft by a connecting rod. The piston rodless cavity is connected to the inlet and outlet on the upper cover through the distribution valve. A side cover is installed on the casing outside the piston cylinder. The upper cover is equipped with an output shaft that rotates synchronously with the crankshaft. By right Count the number of revolutions of the output shaft to achieve flow measurement.

  • The main disadvantages are:
  • The outer circular surface of the output shaft of the existing piston flowmeter and the upper cover adopts O-ring dynamic sealing cooperation.
  • The high-speed rotation of the output shaft is likely to cause wear to the sealing ring, resulting in a decrease in sealing performance and even leakage.
  • In addition, there are errors in the machining dimensions of the inner cavity of the piston-cylinder of each product. Lead to the measurement error of the piston flowmeter.

Read more General-purpose Flow Totalizer for Data collection and calculation

Features and applications of Piston flow meter

The piston flow meter has a simple structure, reliable work, and a large measuring range.
The measurement accuracy is high and is not affected by viscosity. It can be changed remotely and other advantages.

However, the main components of the measurement part are not corrosion-resistant. Therefore, it can only measure non-corrosive media, such as heavy oil and other petroleum products.

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

Piston flow meter working principle

A piston flow meter is a positive displacement flow meter, which is based on the fact that the piston and the metering chamber have been kept in a tangential sealed state. And there is a fixed eccentric distance metering element piston.

Under the action of the pressure difference, a rotational torque is generated on the piston, which makes the piston perform an eccentric rotation movement.

The number of revolutions of the piston is proportional to the flow rate of the fluid. The piston revolution ratio is recorded by the counting mechanism. Then the total flow of fluid can be measured.

The inlet and outlet of the Piston flow meter are separated by a partition. When the measured fluid enters the metering chamber from the inlet, a pressure difference is formed at the inlet and outlet, forcing the piston to rotate counterclockwise as shown in the figure.

The continuous flow of fluid forces the piston to rotate as shown in the figure, forming two and a half-crescent cavities. The piston is forced to rotate under the action of the pressure difference as shown in the figure. V2 fluid is discharged from the outlet. Rotate under the action of pressure difference. V1 fluid is discharged from the outlet, and the fluid bursting out every revolution of the piston is equal to the sum of V1+V2.

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

Piston flowmeter output signal, such as 4-20mA. The flow signal can be connected to a paperless recorder. Carry out multi-channel flow signal monitoring. What Is A Paperless Recorder?

Piston flowmeter VS gear type flowmeter

Gear flow meters are a type of positive displacement flow meters, used for precise continuous or intermittent measurement of the flow or instantaneous flow of liquid in the pipeline. It is especially suitable for the flow measurement of heavy oil, polyvinyl alcohol, resin, and other high viscosity media.

Piston type flowmeter is an online installation, mechanical flow switch, used for liquid or gas medium. Very small pressure loss, good repeatability, anti-fouling ability, mechanical part, and electronic part are completely isolated, suitable for small flow economy type.

If the flow rate you want to measure is not large, the piston type is better.
If you want to measure a large flow rate, just use a gear type.
If the gas flow is measured, only the piston type can be used

Extended reading: Positive displacement flow meter working principle.

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A Piston Flow Meter is an innovative device that accurately measures fluid flow in pipelines. Sino-Inst, a well-established manufacturer and supplier of Piston Flow Meters, boasts a wealth of experience in the field.

With our top-notch product line, Sino-Inst is the perfect partner for all your flow measurement needs. If you’re in the market for a reliable and efficient Piston Flow Meter, look no further! Contact Sino-Inst today and let them show you what they can do.

And that’s not all, Sino-Inst also offers a range of other flow meters, including turbine flow meters, magnetic flow meters, and more. Let Sino-Inst help you find the perfect flow meter solution for your specific application!

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Powder Silo/Bin Level Measurement and Control System

The Silo/Bin level measurement and control system solves the problem of frequent dumping accidents in the powder silo of the mixing station during the feeding process. It avoids the problems of dust flying, waste of cement, and environmental pollution. It reduces the equipment damage caused by the collapse of the dust removal hood of the mixing station Other issues and prevents the safety issues of the workers present.

The importance of Silo/Bin level monitoring

In the production process of the mixing station, the material in the powder silo is replenished in time by means of pneumatic conveying. Most of the dust collectors on the top of the powder silo of the mixing station lack normal maintenance. During the replenishment of the tank body, the pressure of the powder silo is too high, causing “roof fall”. Cement overflows from the dust collector or safety valve. Or “lift the top”, the separation of the top cover of the powder silo from the body of the powder silo occurs.

The intelligent safety system of the powder silo passes through the intelligent detection equipment installed on the silo. achieve:

  • Predict the amount of storage in the warehouse and control the amount of feed;
  • Three-level protection to prevent the occurrence of “top falling” and “lifting top” accidents;
  • Prevent the wrong storage of cement, fly ash, and mineral powder, and prevent construction quality accidents;
  • Cloud platform monitoring platform, real-time monitoring of the status parameters of the powder silo;

Extended Reading: What is level transmitter working principle?

Silo/Bin material level measurement system

System Features

  • Instead of “manual hammering”, the remaining amount of materials in the warehouse can be controlled at any time to provide a basis for procurement and inventory;
  • The resistance rotary switch is intelligently controlled, and the signal is incorporated into the material level measurement system, which greatly extends its service life;
  • Real-time alarm on the feeding surface when feeding, to prevent the occurrence of “roof fall” accidents;
  • The application of product intelligent diagnosis algorithm solves the difficulties of heavy hammer level gauges in the industry that it is too faulty and difficult to maintain;
  • The control system adopts a distributed network system, wireless transmission, stable and reliable, and fast wiring;
  • Reserved information interface to meet the needs of remote control and ERP management system;
  • Distributed control system layout, display the working status of the entire system and equipment parameters on the touch screen;

Extended reading: PID Controller Working Principle

Important components of the system

  1. High-altitude material level detector

Installed on the top of each silo, it is the main measuring equipment of the material level measuring system. It can more accurately monitor the amount of storage in the warehouse in real time, and has the characteristics of resistance to heavy dust and long service life.

  1. High-performance anti-rotation level switch

The anti-rotation material level switch is installed vertically downward to detect whether the motor is working. Through the safety feeding valve to start and stop the rotation resistance, the service life is extended to 3-5 years; with the central control touch screen alarm and the ground terminal alarm, it can effectively prevent the occurrence of “top falling” accidents.

  1. Central control system

It adopts a 15-inch touch LCD screen, an embedded operating system, and is equipped with the material level measurement system software independently developed by the company. The equipment adopts 485 communication interface, which has the characteristics of fast transmission rate, high signal strength, and low failure rate.

  1. Ground display terminal

One set is equipped at the bottom of each silo, which is used for sound and light alarm when the material level triggers the anti-rotation switch alarm (synchronized with the weighing room alarm), real-time display of material weight and percentage, promptly reminding the operator to take measures to avoid accidents.

  1. Safety feeding valve

The safety feeding valve is installed at the feeding port of the powder silo, which can effectively prevent the wrong silo from loading, reduce management costs, ensure the quality of concrete, and prevent production accidents.

  1. Remote display

Remote monitoring shows whether the current silo can be loaded, and guides the vehicle to load the corresponding silo.

Featured Silo Level Sensors

Extended reading: Magnetostrictive Hydraulic Cylinder Position Sensor

Advantages of Radar Silo Level Sensors

High frequency radar Silo Level Sensor is currently the mainstream product for measuring solid level in the world. When measuring solid material level, compared with low frequency radar, high frequency radar has the following advantages:

1) High-frequency radar level gauges (mainly 26GHz and 24GHz) have the advantages of high energy, small beam angle and high precision. However, low-frequency radars have low energy and scattered energy, so all launch angles are large and the directivity is poor. When the diameter of the horn antenna of the low-frequency pulse radar is Φ246, the beam angle is only 15°).

2) The wavelength of 26GHz radar is 11mm, and the wavelength of 6GHz radar is 50mm. When the radar measures the bulk material level, the radar wave reflection mainly comes from the diffuse reflection of the material surface. The intensity of diffuse reflection is proportional to the size of the material and inversely proportional to the wavelength. That is to say, for the same material, the shorter the wavelength is, the easier it is to be reflected, so the echo signal is better during radar measurement. The diameter of most bulk materials is far less than 50mm, which is why 26GHz radar is currently the best choice for bulk material level measurement.

3) Due to the harsh environment on site, dirt, water vapor, etc. will accumulate on the radar antenna over time. The 26GHz radar antenna is small, adding a radome can greatly improve the impact of dirt and water vapor. The 6GHz radar antenna is large, and it is very difficult to add a radome. The overall instrument is large and difficult to clean.

4) When the low-frequency radar (6GHz) measures solids, the measurement range will not exceed 30m. It cannot meet all level measurements of cement lines above 2500T/d scale. The general measurement range of high-frequency radar can reach 70 meters, or even 100 meters. It can fully meet all silos of cement production lines of all scales at present.

5) Because the high-frequency radar level gauge has good directivity and small launch angle. Strong anti-interference ability and so on. It is determined that it is very suitable for the measurement of silos with large aspect ratios. Especially such as calcium carbide furnace material level, converter silo and other material level measurement. Neither of these situations can be measured with low frequency radar.

6) Low frequency radar compared to high frequency radar. Due to its low frequency, the energy is scattered and the energy is not concentrated enough. Therefore, the ability to fight against dust is far inferior to high-frequency radar.

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

Safe feeding system for powder silo

The remote display of the weighing room shows the warehouse number and the material is allowed to be loaded. The driver holds the card to the ground display terminal and swipes the card if the warehouse allows loading. When the card number is the same as the warehouse number. Only then can the feeding valve be automatically opened.

After the card is valid, the access control baffle is automatically fully opened within 15 seconds. After swiping the card again, the access control shutter will automatically be fully closed within 15 seconds.

The powder safety feeding valve system comes with a closed door detection. Real-time detection of closed door status.

The feeding valve cannot be opened without swiping the card or reading the correct ID information

After loading, the driver needs to swipe his card to close the access control. Then go to the weighing room to hand in the card, otherwise the system prompts that the access control is open. The weighing house will not weigh the vehicle.

At present, the loading port of the cement silo of most mixing plants adopts simple mechanical locking methods. In actual production, it is easy to cause the wrong material to enter the silo, and the loading is not closed and locked. The intelligent material level system for powder silo developed by our company. It has the advantages of easy installation and maintenance, accurate measurement, high safety in use, and no need to stop production during installation. It is currently the preferred solution for real-time measurement of the powder silo level on the market.

Extended reading: 5 Industrial Propane Tank Level Indicators

Solid flow meter | For bulk solids-powder-soybean-cement 

In fact, in addition to monitoring the material level of the bin, we can also know the material level of Silo/Bin by monitoring the flow of solid particles or powder.

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 of solids such as powder, dust, pellets, granules, etc., which are pneumatically conveyed or in free fall (1nm-20mm). Solid flow meters are also called solid powder flow meters, intelligent electrostatic powder flow meters, solid dust flow meters, coal powder flow meters, mineral powder flow meters, lime flow meters, cement flow meters, flour flow meters, petroleum coke powder flow meters.

Read more about: Solid Flow Meter Parameters

More Featured Level Measurement Solutions


Simply put, silo levels measurement is divided into contact and non-contact measurement. Technical measures are taken to detect the accumulation height and surface position of granular materials in coal storage bins (raw coal bins, buffer bins, product bins, etc.) in the coal preparation plant. The equipment for detecting the grain position is called the level gauge.

Extended reading: GWR Solid Level Sensor-for Cement silo-Ash powder measure

The point level sensor can indicate whether the fluid level is higher or lower than a specific point. Usually the point level switch is used as a warning indicator. When the liquid level is too high or too low, an alarm is triggered and the liquid level is kept between two points.

Point level sensors have a wide range of types and are suitable for many applications and materials. The float level sensor is a common point level sensor. The float level switch is composed of a fixed rod and afloat; the float has a built-in permanent magnet that moves freely along the fixed rod as the liquid level rises and falls. The magnetic field of the permanent magnet acts on the reed switch. The closer it is to the reed switch, the stronger the force will be. After the threshold, the reed switch is closed. The float level sensor has a sturdy and durable structure and the measurement deviation is less than 1%.

When every possible intermediate level of a tank or container needs to be measured, a continuous level sensor is required, also known as continuous level measurement. This means that the sensor will provide feedback regardless of the liquid level.
For applications that require continuous level measurement such as fuel tanks and storage tanks, the continuous level sensor can indicate the fluid level in a given container that is within the range.

The radar level sensor is a radar level gauge based on the principle of time domain reflection (TDR). The electromagnetic pulse of the radar level gauge propagates along the steel cable or probe at the speed of light. When encountering the surface of the measured medium. Part of the pulse of the radar level gauge is reflected to form an echo and returns to the pulse transmitter along the same path. The distance between the transmitting device and the surface of the measured medium is proportional to the propagation time of the pulse between them. The height of the liquid level is calculated.

Read more: Non-Contacting Radar Level Measurement

Sino-Inst offers more than 40 powder silo/silo level measurement and control systems. About 50% of them are level gauges and 50% are silo level sensors. Suitable for highest and lowest level product detection, they can be installed in flat bottom silos and hopper silos to prevent silos from overflowing or emptying.

There are various powder silo/silo level measurement and control systems for you to choose, such as free samples, paid samples.

Sino-Inst is a globally recognized powder silo/silo level measurement and control system instrumentation supplier and manufacturer, located in China.

Sino-Inst offers a wide range of high-quality silo level sensors designed for various environments at competitive prices. Helps operators accurately monitor and measure liquid level and flow in silos. A range of non-contact solutions means that the operator does not have to come into direct contact with any substance. It also means that the process is not interrupted.

Sino-Inst’s entire team is well trained, so we can ensure that each customer’s needs are met. If you need any help with your product requirements, whether it is a silo level sensor, level sensors, or other equipment, please give us a call.

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Bidirectional Flow Measurement

What is bidirectional flow?

Bidirectional flow refers to forward and directional flow. Bi-directional flow lines are not common in most process plants. The measurement of unidirectional flow is easy to understand and is applicable to all types of flow technologies. However, most flow technologies cannot accurately measure two-way flow.
They always cause difficulties for process and instrument designers. For two-way flow, the pipeline scheme uses the same pipeline to achieve the transport and/or control function of the opposite flow (forward or reverse flow) according to the process conditions and goals.

Can the flow meter perform bidirectional measurement?

If the flow direction of the medium in the pipeline is reversed. Does the flow meter need to be installed with a flow meter for forwarding use and a flow meter for reverse use accordingly? Is there a flow meter for normal measurement that does not consider the flow direction?

  1. If you just look at the flow rate, you can. For example, an electromagnetic flowmeter. It doesn’t matter if you measure in the whole direction or in the reverse direction. Change the reverse measurement to allow in the prerequisite electromagnetic flowmeter settings.
  2. It’s hard to say if you still need a cumulative amount. How do you convert the cumulative amount you measured forward and the cumulative amount you measured backward? Whether to subtract or add depends on your actual situation.

Extended reading: Insertion Ultrasonic Water Flow Meter – Designed for Agricultural Irrigation, Garden Management

How does the ultrasonic flowmeter realize bidirectional flow measurement?

The principle of the ultrasonic flowmeter is to calculate the fluid flow rate using the difference in sound velocity. And multiply the fluid velocity by the area to calculate the volume flow.

Usually, there is an incident angle between the probe of the ultrasonic flowmeter, that is, the transducer and the meter body. From 60 degrees to 45 degrees. Ultrasonic waves propagate between a pair of probes if there is no fluid, that is, at zero flow. The travel time back and forth is the same. It is equivalent to a zero flow rate.

Extended reading: Ultrasonic Flow Meters Types & Technical Guide

Once there is fluid, the speed of the ultrasonic flowmeter back and forth between a pair of probes is different. Regardless of the direction of fluid flow, there will be a difference in sound velocity. If one direction is set as the normal flow direction, then the normal sound velocity should be a positive number. If the sound velocity difference is negative, the flow is in the opposite direction. That is reverse measurement. The measurement accuracy of the two directions is the same.

Extended Reading: Inline Ultrasonic Flow Meter

Can a vortex flowmeter measure bidirectional flow?

You cannot measure bidirectional flow with just one vortex flowmeter. But in some applications, you can use two for this.

The vortex flowmeter has a bluff body in front of the sensor, which is used to generate the vortex in the flow. As far as I know, no flowmeter has two bluff bodies to measure bidirectional flow.

If you have a two-way steam application. Then you can install two vortex flowmeters in the same line, as long as you respect the inlet and outlet operation of both. However, depending on the size of the line, this setting may become expensive.

Read more General-purpose Flow Totalizer for Data collection and calculation

Bidirectional orifice flowmeter

The bidirectional orifice flowmeter is a differential pressure flowmeter. Mainly used for flow measurement of liquid and gas. According to the characteristics of the orifice flowmeter, it has the advantage of high temperature and high pressure. Therefore, the orifice flowmeter is widely used in the field of high temperature and high-pressure measurement. The orifice flowmeter has high accuracy and good stability and is unanimously recognized by users.

What kind of measurement conditions will use an orifice flowmeter to measure? It can be used according to the requirements of the site, such as typical boiler steam, the general temperature can be close to about 500 degrees, and general flow meters cannot be used. However, the orifice flowmeter can effectively solve this high-temperature working condition, and the only disadvantage is its high cost of use.

Extended reading: 2 inch Water Flow Meter

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Extended reading: Integral DP Flow Meter|Gas, liquid, steam|Compact structure

Sino-Inst offers over 50 flow meters for flow measurement. About 50% of these are differential pressure flow meters, 40% are the liquid flow sensor, and 20% are Ultrasonic Level Transmitter and mass flow meters.

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

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

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