Monthly Archives: March 2019

SMT3151DP Smart Differential Pressure Transmitter

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Smart Differential Pressure Transmitter measures an industrial differential pressure. Can Works with diaphragm seals, capillary, HART. Outputs standard signals (such as 4 ~ 20mA, 0 ~ 5V).

SMT3151DP smart differential pressure transmitter

A smart differential pressure transmitter is used to measure the liquid level, density, and pressure of liquid, gas, or steam. And then convert it into 4 ～ 20mA DC signal output. Smart can communicate with HART Communicator, and set and monitor through it. The DP transmitter is a transmitter that measures the pressure difference between the two ends of the transmitter. The differential pressure transmitter has two pressure interfaces. It is divided into a positive pressure end and a negative pressure end. In general, the pressure at the positive pressure end of the differential pressure transmitter should be greater than the pressure at the negative pressure end.

Sino-Inst offers a variety of samrt differential pressure senors for industrial pressure measurement. If you have any questions, please contact our sales engineers.

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More DP Transmitters

Features of SMT3151DP Smart Differential Pressure Transmitter

Blue and white custom housing smart differential pressure transmitter
  • Output signal 4-20mA output+HART communication;
  • Push Button Configuration;
  • Self-diagnosis capability;
  • Range coverage is 0-0.1KPa~41.0MPa;
  • Good stability, high precision, adjustable damping, strong resistance to one-way overload.
  • Explosion-proof housing structure.
  • LCD display

You may like the pressure level transmitter

SMT3151DP smart differential pressure is the pressure signal measured at the reference end of the low-pressure side. There are two ports connected to the processing pipeline.

Smart differential pressure transmitter is suitable for measuring pressure from -100mbar to 70bar. The maximum working pressure is up to 410bar. Sino-Inst’s SMT3151DP smart differential pressure transmitter is a rugged low-range / high-voltage line process differential pressure transmitter. Optional HART communication and 4-20 mA output provide an accurate measurement. Equipped with internal button adjustment for range and configuration and integrated LCD display.

Extended reading: How to calibrate HART pressure transmitters

Specifications of SMT3151DP Smart Differential Pressure Transmitter

Use object: liquid, gas or steam

Measuring a range of SMT3151DP smart differential pressure transmitter:

ModelTransmitter type
DPPressure transmitter
HPAbsolute pressure transmitter
CodeScale range
20-0.10～3.5kPa(0-10～350mmH2O)
30-0.8～8.0kPa(0-80～800mmH2O)
40-4.0～40kPa(0-400～4000mmH2O)
50-20～200kPa(0-2000～20000mmH2O)
60-70～700kPa(0-0.7～7kgf/cm2)
70-210～2100kPa(0-2.1～21kgf/cm2)
80-700～7000kPa(0-7.0～70kgf/cm2)
90-2.1～21MPa(0-21～210kgf/cm2)
00-4.1～41MPa(0-41～4100kgf/cm2)
CodeOutput form
ELinear output 4-20mAdc
SFLinear/square root output 4-20mAdc +HART signal,，Full function buttons on site
FMODBUS-485 signal
Structural materialsFlange connectorExhaust/Drain valveIsolation diaphragmFilling liquid
22316 Stainless steel316 Stainless steel316 Stainless steelSilicone oil
23316 Stainless steel316 Stainless steelHastelloy CSilicone oil
24316 Stainless steel316 Stainless steelMonelSilicone oil
25316 Stainless steel316 Stainless steelTantalumSilicone oil
33Hastelloy CHastelloy CHastelloy CSilicone oil
35Hastelloy CHastelloy CTantalumSilicone oil
44MonelMonelMonelSilicone oil
CodeShell materialConduit inlet dimensions
ALow copper aluminum alloy polyurethane coatingM20×1.5
BLow copper aluminum alloy polyurethane coating1/2-14 NPT
CStainless steelM20×1.5
DStainless steel1/2-14 NPT
CodePressure connection
L11/4NPT-18 Internal thread（excluding waist joint standard）
L21/2NPT-14 Internal thread
L3M20×1.5 External thread
CodeOptional parts
M4LCD multi – power digital display head
B1Pipe bending bracket
B2Plate bending bracket
B3Pipe mounting bracket
C02M20×1.5 nut and Φ 14 pressure short tube
C121/2NPT-14 external thread and Φ14 pressure short tube
C221/4NPT-18 external thread and Φ14 pressure short tube
C321/4NPT-18 to M20×1.5 external thread
C421/2NPT-14 to M20×1.5 external thread
C431/2NPT-14 to 1/4NPT-18 internal thread
C441/2NPT-14 to 1/2NPT-14 external thread
C451/2NPT-14 to G1/2 external thread
D1The side discharge valve is on the upper part
D2The side discharge valve is on the upper part
X1Oil ban
DaFlameproof ExdIIBT5Gb;(explosion-proof certificate no. : CE16.1163)
FaIntrinsically safe ExiaIICT4/T5/T6Ga;(explosion-proof certificate no. : CE15.2354X)

You may like: High temperature pressure transmitter | Magnetostrictive level sensor | Magnetostrictive level transmitter

Applications of Smart Differential Pressure Transmitter

SMT3151DP smart differential pressure transmitter is suitable for applications like:

Flow measurement;

Level monitoring;

Steam measurement;

Filter or pump differential pressure;

Critical process monitoring.

The common DP transmitter is the most commonly used test instrument in industrial process control.It is widely used in various automatic control systems.

Such as aerospace, military, petrochemical, chemical. Oil Wells, electric power, ships, building materials.Pipelines and many other industries.

Generally used in liquid, gas or steam differential pressure, flow measurement. The medium temperature is not too high, corrosion is not strong, viscosity is not high, not easy to crystallize and other environments.

If the working static pressure exceeds 13MPa, a high static differential pressure transmitter should be selected.

You may like: Differential Pressure Transmitter Installation Guide

The common DP transmitter is the most commonly used test instrument in industrial process control.It is widely used in various automatic control systems.

Such as aerospace, military, petrochemical, chemical. Oil Wells, electric power, ships, building materials.Pipelines and many other industries.

Generally used in liquid, gas or steam differential pressure, flow measurement. The medium temperature is not too high, corrosion is not strong, viscosity is not high, not easy to crystallize and other environments.

If the working static pressure exceeds 13MPa, a high static differential pressure transmitter should be selected.

You may like: Differential Pressure Transmitter Installation Guide

Differential pressure transmitter for liquid level measurement

Differential Pressure (DP) Level Measurement uses pressure readings and specific gravity to output level. DP Level is a common measurement technique that is used in a wide variety of applications. Solutions include standard transmitter connections and integrated transmitters with direct or remote mount seals that can be configured in tuned, balanced, and electronic systems. Additional Wireless options are also available.

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Differential pressure transmitter for flow measurement

Differential Pressure Flow meters, also known as DP flow meters. Differential Pressure (DP) flow meters introduce a constriction in the pipe, that creates a pressure drop across the flow meter. The calculation of fluid flow rate, by reading the pressure loss across a pipe restriction, is the most used flow measurement technique in industrial applications. Differential pressure flow meters are suitable for water flow measurement, oil, steam or gas flow measurement.

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Differential Pressure Transmitter Pdf

SM3151DP-Differential-Pressure-TransmitterDownload

Smart pressure transmitter working principle

The working principle of the smart pressure transmitter (gauge pressure) / absolute pressure transmitter is:

The pressure passes through the isolated diaphragm and the pressure-conducting medium. It acts indirectly on the metal surface. The thickness of the metal film is different. As a result, the diaphragm is slightly deformed. The maximum shape variable does not exceed 0.1mm. A high-precision circuit that measures the deformation of the diaphragm converts this small deformation into a voltage signal proportional to the pressure. After linearization and temperature compensation processing, a dedicated chip is used to convert the voltage signal into an industry standard 4-20ma current signal or 1-5v voltage signal.

The metal capacitive pressure sensor used to measure the diaphragm detection circuit contains a linear circuit and a temperature compensation circuit. Therefore, the entire transmitter can achieve high accuracy and high stability. Metal capacitive pressure sensor has extremely high overload resistance. And has excellent performance in micro-pressure measurement.

Working principle of Smart differential pressure transmitter

SMT3151DP intelligent differential pressure transmitter uses advanced microprocessor technology and digital communication technology. The basic principle of differential pressure transmitter is: divide a space with sensitive elements (multi-purpose capsule) into two chambers. Introduce pressure into the two chambers separately. The sensor produces displacement (or displacement trend) under the combined action of the two pressures. This displacement is proportional to the pressure difference (differential pressure) between the two chambers. Convert this displacement into a standard signal output that can reflect the magnitude of the differential pressure.

You may like: differential pressure transmitter working principle|Working Principle of pressure level transmitters| differential pressure level transmitter working principle

Type selection of SMT3151DP smart differential pressure transmitter:

Before selecting the type, the User shall make clear:
The temperature. Corrosion. Measuring range. Use.
Whether the medium under test is explosion-proof.
Whether the oil shall be forbidden.
Whether the medium is easy to crystallize or thicken.
Whether the diaphragm flange connection is needed, etc.

Read more What is a diaphragm seal?

https://www.drurylandetheatre.com/wp-content/uploads/2019/03/SMT3151DP-smart-differential-pressure-transmitters-manufacturer.mp4?_=1

3 Methods for SMT3151DP Smart Differential Pressure Transmitter Application Measurement:

(1) The differential pressure transmitter is combined with the throttling device (like the orifice plate). To convert the flow rate according to the differential pressure value, generated before and after the throttling device.

SMT3151DP smart differential pressure transmitters supplier

(2) Measuring the height of the liquid by the pressure difference, generated by the gravity of the liquid itself.

(3) Directly measure the pressure difference between different pipes, and closed pressure vessels to convert the liquid level height.

The SMT3151DP smart series differential pressure transmitters are modular in design. And consist of a sensor module with an integrated electronic adapter unit. And an amplifier module with a local button unit.

The sensor module includes a differential pressure sensor and a temperature sensor for simultaneous measurement of differential pressure.

So the SMT3151DP smart series differential pressure transmitter has excellent static pressure characteristics and temperature characteristics.

Frequently
Asked
Questions

Help Center

Smart transmitters work on the function of microprocessors for signal transmission.

Smart pressure transmitter consists of two parts: smart sensor and smart electronic board.

The intelligent sensor part includes: capacitive sensor, measuring diaphragm detection circuit, temperature sensor and temperature compensation circuit.

The part of the intelligent electronic board includes: a microcomputer controller and peripheral circuits. It completes the conversion of the pressure signal to 4-20mA dc.

Extended Reading: Digital Pressure Sensor-RS485

Depending on the type of pressure to be measured:

Pressure transmitter types include gauge pressure, absolute pressure, and differential pressure. Gauge pressure refers to the pressure that is less than or greater than atmospheric pressure based on the atmosphere. Absolute pressure refers to the absolute zero pressure as the reference and is higher than the absolute pressure. Differential pressure refers to the difference between two pressures.

According to the working principle of the pressure transmitter:

  • Strain Gauge Pressure Transducers
  • Capacitance Pressure Transducers
  • Potentiometric Pressure Transducers
  • Resonant Wire Pressure Transducers

Extended reading: Silicon Pressure Sensor

Simply put, a differential pressure transmitter is a device that measures two opposing pressures in a pipe or vessel. Differential Pressure (DP) transmitters measure the difference between two pressures. They use a reference point called the low-side pressure and compare it to the high-side pressure. Ports in the instrument are marked high-side and low-side. The DP reading can be either negative or positive depending on whether the low-side or high-side is the larger value. A DP transmitter can be used as a gauge pressure transmitter if the low-side is left open to the atmosphere.

Extended reading: Featured Diaphragm Seal Pressure Transmitters

The most common and useful industrial pressure measuring instrument is the differential pressure transmitter. This equipment will sense the difference in pressure between two ports and produce an output signal with reference to a calibrated pressure range.

The differential pressure transmitter can be used in combination with other accessories and can be used to measure liquid level and flow.

Differential pressure transmitters and pressure transmitters have many similarities. It can be mixed and used most of the time. As long as it is within the range of the differential pressure transmitter, it can measure not only positive pressure but also negative pressure. When measuring positive pressure, the negative port is open to atmosphere, and when measuring negative pressure, the positive port is open to atmosphere.

Differential pressure transmitters can also measure flow, pipeline pressure difference, tank liquid level, bubble water level, dust, or medium that is easy to crystallize and viscous and fluidity is not good.

Sino-Instrument is a leading manufacturer in the field of measurement and control in China.
One big reason for the continued growth of Sino-Instrument is our willingness to listen to our customers’ specific needs.

And develop solutions to meet those needs for the Oil and Gas, Power Generation, and Nuclear industries. In fact, many of the products we deliver are specially engineered to order. Such as pressure gauges, bimetal thermometers, thermocouples, pressure calibrators, bench pressures, etc.

It is widely used in electric power, petroleum, chemical, machinery, metallurgy, cement, glass, cooking, and other industries in various countries.

More products continue to be developed that integrate features, such as wireless and HART technologies (AMS TREX DEVICE). All our products are engineered and manufactured, at Sino-Instrument world headquarters located in Xi’an, China.

Sino-Instrument manufactures a wide variety of mechanical and electronic devices. To measure pressure, level measurement, temperature, and flow. And we’re working constantly to improve our product platform.

Sino-Instrument specializes in supplying electromagnetic flowmeters.
vortex flowmeter. gas turbine flowmeter. vortex flowmeter. orifice flowmeter. liquid turbine flowmeter. natural gas flowmeter. steam flowmeter. thermal gas flowmeter. elliptical gear flowmeter. magnetic flap level gauge. ultrasonic level gauge. diaphragm pressure gauge.
digital pressure gauge. diaphragm pressure gauge. stainless steel Series of flowmeters.

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SMT3151LT Differential pressure(DP) level transmitter

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Differential pressure (DP) level transmitter is a perfect solution for tank level measurement. Flanges, seal diaphragms, capillaries, and DP transmitters are often used to measure liquid levels.

Differential pressure(DP) level transmitter is often used as a tank level transmitter. The DP transmitter is connected with a stainless steel flange by the capillary. Flange installation. The pressure is sensed by a remote transmission device installed on the container. The pressure is transmitted to the body of the transmitter through the capillary. The transmitter converts the pressure or differential pressure to 4 ～ 20mA. The DC signal is output. It can communicate for the setting and monitoring by cooperating with the HART communicator. Explosion-proof available.

Sino-Inst offers a variety of DP pressure transmitters for industrial pressure measurement. Connection with diaphragm seals. If you have any questions, please contact our sales engineers.

CONTACT US
More DP Transmitters

Features of Differential pressure (DP)level transmitter

  • The biggest feature of the differential pressure transmitter is that it can be easily installed on existing vessels. It can also be converted into a working tank or container.
  • The maintenance of the DP transmitter is easy because it can be isolated from the process by an isolation valve.
  • DP transmitter is ideal for liquid level measurement. It can also be used for light mud with an extended diaphragm, which can be installed flush on one side of the container.
  • Level measurement via DP transmitter is more cost-effective than other available sensors.
  • Since the DP transmitter is far away from the tank for liquid level measurement, it is easy to clean and maintain the tank.
  • The detection element takes up almost no space in the container. Instead, only two pressure holes need to be opened in the container wall.
  • There is no movable part in the detection part. Installation method, the work is more reliable.
  • The weight of the liquid column height per unit area is measured. The change of the measured medium weight will directly affect the measurement result. When the purpose of the measurement is to determine the weight storage of the material in the container. No additional amendments are required.
  • The use of flange pressure can solve the liquid level measurement of high viscosity, easy to crystallize, and medium with suspended matter. Evaporation and boiling liquid level can also be measured, but sometimes the error is large.
  • The display part of the instrument can usually adopt the general unit in the unit group instrument. No separate design is required.

There are four types of remote transmission devices for remote differential pressure transmitters:

  1. Flat type
  2. Thread mounting type
  3. Flange mounting type
  4. Extended Diaphragm Seal

Specifications of DP level transmitter

Measuring mediumLiquids, gases and steamPressure range0-0.1kpa-40mpa
Signal output4-20mA, superimposed Hart protocol, RS485Plywood materialAll 316L stainless steel
Supply voltage12-30VDCPrecision± 0.2% FS, ± 0.1% FS, ± 0.075% FS (customizable)
Diaphragm material316L, customizable Ha C, tantalum, Monel alloyTemperature compensation-10 ~ + 70 ℃
Long-term stability (1 year)≤ ± 0.25% FSOperating temperature-20 ~ + 100 ℃
Overload pressure200% FSZero rangeExternal continuously adjustable
Destruction pressure300% FSPower effectLess than 0.005% / V of output range
Weight3.9KG (standard type)Protection levelIP65
Volume uptakeLess than 0.16cm3Load impactIf the power supply is stable, the load has no effect

Applications of DP level transmitter

The differential pressure liquid level transmitter can prevent the measured medium from directly contacting the sensor diaphragm of the transmitter. It is suitable for the following situations:

  1.  When the measured medium has a corrosive effect on the transmitter connector and sensitive components;
  2. When the high temperature measured medium needs to be isolated from the transmitter;
  3. When there are solid suspended solids or high viscosity in the measured medium, it is easy to block the transmitter connector and the pressure chamber;
  4. When the measured medium is easily cured or crystallized by the pressure tube;
  5. When changing the measured medium needs to be rinsed and not to be mixed;
  6. Hygienic conditions must be maintained to prevent pollution. .
  7. Changing the measured medium requires strict purification of the measuring head
  8. Suspended liquid or high viscosity medium
  9. Measurement of sealed pressure vessel.

Read more What is a diaphragm seal?

Differential pressure type level transmitter working principle

Differential pressure (DP) level transmitter is a differential pressure transmitter to prevent the measured medium from directly acting on the transmitter. The differential pressure transmitter uses remote transmission isolation diaphragm contact. The remote transmission differential pressure transmitter (double flange) is composed of a differential pressure transmitter and a welded remote flange with capillary tube. Its working principle is the same as the differential pressure transmitter. Only the pressure transmission path is slightly different. The measurement diaphragm chamber of the transmitter is connected with a stainless steel capillary (tube with a diameter of about 3mm, plus protection) and the channel is several meters to tens of meters. One of the other places will be two (pressure or differential pressure) made into a flange-shaped measuring diaphragm box. The middle is filled with the transfer medium (silicone oil). When using, connect the flange to the device to measure.

SMT 3151 Differential Pressure Level Measurement

Differential pressure transmitter level measurement calculation

When using Differential pressure (DP) level transmitter to measure the liquid level as shown in the figure below.
The measured liquid density in the figure is ρ.
The working medium density in the capillary of the double flange differential pressure transmitter is ρ0.
The measuring range of the measured liquid level is H.
The center distance of the sampling tube of the measured liquid level is h.
It can be seen from the figure that the maximum measurement range of the liquid level △ P = P + —P- = H × ρ × g-h × ρ0 × g.

It can be seen from the formula that the dual-flange differential pressure transmitter should perform negative migration. The migration amount S is h × ρ0 × g. And the installation position of the double flange differential pressure transmitter has no effect on the migration amount and the measurement result.

The dual-flange differential pressure transmitter requires negative migration.

When the measured liquid level is 0, the pressure difference between the positive and negative measurement chambers of the remote differential pressure transmitter is the largest. The output current of the double flange differential pressure transmitter is 4mA.

As the measured liquid level rises, the pressure difference between the positive and negative measurement chambers of the transmitter gradually decreases.

When the measured liquid level rises to the highest Hmax. The pressure difference between the positive and negative measurement chambers of the transmitter is the smallest. The output current of the double flange differential pressure transmitter is 20mA.

Read more about Differential Pressure Transmitter Installation Guide

How to calibrate differential pressure transmitter for level

The differential pressure liquid level transmitter has been calibrated in the range, accuracy, linearity and other parameters according to customer requirements at the factory. And mark the range, accuracy, etc. on the nameplate of the differential pressure liquid level transmitter. As long as the density and other parameters of the measured medium meet the requirements of the nameplate, generally no adjustment is required.

If the customer needs to adjust the range or zero position, please adjust according to the following methods. Assuming that the range of the differential pressure liquid level transmitter is 0 ~ 10 meters:

How to calibrate a differential pressure level transmitter ?

  1. Unscrew the protective cover of the differential pressure liquid level transmitter. It can be adjusted by connecting external standard 24VDC power supply and ammeter (requires accuracy of 0.2% or above).

  2. When there is no liquid in the differential pressure liquid level transmitter. Adjust the zero potentiometer. Make it output current 4mA.

  3. Pressurize the differential pressure liquid level transmitter to full scale (10 meters). Adjust the full-scale resistor. Make it output current 20mA.

  4. Repeat the above steps two or three times until the signal is normal.

  5. Please input 25%, 50% and 75% signals to check the error of the differential pressure liquid level transmitter.

  6. For non-aqueous media. Differential pressure level transmitters are calibrated with water. It should be converted according to the pressure generated by the actual density of the medium. For example, when the medium density is 1.3, the 1.3m water level should be used to calibrate the 1m range.

  7. After adjustment, tighten the protective cover.

  8. The verification cycle of the differential pressure liquid level transmitter is once a year.

  9. HART intelligent differential pressure liquid level transmitter of Sino-Inst instrument can be selected. It is convenient to adjust the range of the differential pressure liquid level transmitter.

Extended reading: How to calibrate HART pressure transmitters

You may like: pressure level transmitter

What is the difference between pressure transmitter and differential pressure transmitter?

The principle of the pressure transmitter is: The medium pressure acts directly on the sensitive diaphragm. A Wheatstone bridge composed of resistors distributed on the sensitive diaphragm. The use of the piezoresistive effect realizes the conversion of pressure into an electrical signal. Amplify the millivolt signal generated by the sensitive element through an electronic circuit into an industrial (such as 4 ~ 20mA, 0 ~ 5V) standard signal. But the pressure transmitter has only one pressure interface.

Pressure transmitters

The principle of a differential pressure transmitter is: a transmitter that measures the pressure difference between the two ends of the transmitter. Output standard signals (such as 4 ~ 20mA, 0 ~ 5V). Differential pressure transmitters are different from general pressure transmitters in that they have two pressure interfaces. Differential pressure transmitters are generally divided into positive pressure end and negative pressure end. H is the positive pressure end and L is the low-pressure end. In general, the pressure at the positive pressure end of the differential pressure transmitter should be greater than the pressure in the negative pressure section to measure. Differential pressure transmitters are used to measure the level, density, and pressure of liquids, gases, and vapors. Then convert it into 4–20mA DC current signal output.

In summary: The fundamental difference between a pressure transmitter and a differential pressure transmitter is that the pressure transmitter can only measure the pressure at one pressure end. The differential pressure transmitter can measure the pressure at two pressure points, and the two pressures are subtracted. The pressure difference at the positive pressure end minus the negative pressure end pressure. Thus, the actual liquid level value is converted.

https://www.drurylandetheatre.com/wp-content/uploads/2019/03/SMT-3151-Differential-Pressure-Level-Measurement-supplier.mp4

Sino-Instrument (drurylandetheatre.com) offers over 100 DP transmitters for liquid level, pressure, flow, temperature measurement. Differential pressure (DP) level transmitters suit to measure water and another liquid level.

A wide variety of DP-level transmitters are available to you. Such as SMT3151LT Differential pressure level transmitter.

You can also choose from the liquid flow meters and pressure transmitters, not specified. We are a differential pressure level transmitter supplier, located in China. The top supplying country is China(Mainland), which supply 100% of DP transmitters respectively.

Differential pressure level transmitter is most popular for India, Pakistan, South Africa, The US. The quality is the same as the original premium quality. You can ensure product safety by selecting from our products, including IOS9000, … certification. You can find more information about our SMT3151LT DP Level transmitter, you can refer to our differential pressure level transmitter pdf:

SM3151LT liquid level pressure-differential pressure transmitterDownload

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Industrial Magmeters

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What is a Magmeter?

Magmeter is a volumetric flow meter that measures the flow of conductive fluid in a closed pipeline. Magmeter is also called electromagnetic flow meter, magnetic flow sensor, magnetic flow meter, etc. Magmeters is based on electromagnetic induction technology and outputs 4-20mA and other signals. Used in wastewater treatment, sewage treatment, chemical plants, etc.

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Advantages of Magmeters

  • The cost is relatively low.
  • No mechanical parts such as rotors or gears.
  • There is almost no pressure loss.
  • There are a variety of materials for the lining and electrode to meet the measurement of various corrosive fluids.
  • Various installation forms are available: integrated, split, plug-in, sanitary, high-pressure, etc.
More Flow Meters
Magnetic Flow Meters

    • Structure of Magmeter

    First, let us look at the structure of the magmeter.

    The structure of electromagnetic flowmeter is mainly composed of magnetic circuit system, measuring catheter, electrode, shell, lining and converter.

    Magnetic flow meter principle

    The electromagnetic flowmeter is made according to Faraday’s law of electromagnetic induction. It is used to measure the volume flow of conductive liquid.

    Faraday’s law of induction (referring to the induction of an electric potential inside the conductor when the conductor passes through a magnetic field) is the basic principle of electromagnetic flowmeter measurement.

    This measurement principle can be applied to conductive fluids.

    The fluid flows into a pipe whose magnetic field is perpendicular to the direction of the fluid, and the electric potential induced in the fluid can be measured using two symmetrically arranged electrodes.

    The signal voltage UE is proportional to the magnetic induction intensity B, the electrode spacing D and the average fluid velocity v.

    Because the magnetic induction intensity B and the electrode spacing D are constant. Therefore, the signal voltage UE is proportional to the average flow velocity v.

    The equation used to calculate the volume flow rate shows that the signal voltage UE is linearly proportional to the volume flow rate.

    The sensed signal voltage is converted into the graduation in the converter, analog and digital output signals.

    Magmeter flowmeters measure the velocity of conductive liquids (such as water, acid, caustic and slurry) in the pipeline. When measuring deionized water, the minimum conductivity of the medium is 20uS/cm. For most liquids, the minimum conductivity required for measurement can be 5uS/cm.

    Magmeter is mainly used in the following areas:

    • Measure clean water, sewage, domestic water, raw water;
    • Various acid, alkali, salt and other solutions;
    • Mud, mineral pulp, paper pulp, and food liquids, etc.;
    • It is widely used in metallurgy, papermaking, water treatment, chemical industry, light industry, textile, food and beverage, catering, agricultural irrigation, hydropower station, oil production, electric power and mining industries.

    Extended Reading: Guide: Magnetic Flowmeter Installation

    Magmeter liner selection should be selected according to the corrosiveness, abrasiveness and temperature of the measured medium.

    • Hard/soft rubber is resistant to general weak acid and alkali corrosion. Temperature resistance is 65℃. Soft rubber has abrasion resistance.
    • Polytetrafluoroethylene (PTFE) is almost resistant to strong acid and alkali corrosion except hot phosphoric acid. The temperature of the medium can reach 130℃. But it is not resistant to wear.
    • Polyurethane rubber has good wear resistance. But it is not resistant to acid and alkali corrosion. Temperature resistance is also poor. The medium temperature is less than 65°C.
    Liner MaterialsFunctionsApplications
    Hard rubber1. It is resistant to hydrochloric acid, acetic acid, oxalic acid, ammonia, phosphoric acid and 50% sulfuric acid, sodium hydroxide, and potassium hydroxide at room temperature.
    2. Avoid strong oxidants.     		1, below 70℃
    2. General acid, alkali, and salt solutions. 
    Soft rubber1. It has good elasticity and good wear resistance;
    2. It is resistant to the corrosion of general low-concentration acids, alkalis, and salt media, and is not resistant to the corrosion of oxidizing media.     		1. Below 70℃;
    2. Measure general water, sewage, mud, ore slurry
    Polytetrafluoroethylene (PTFE)
    Modified polytetrafluoroethylene (PFA)    		1. The material with the most stable chemical properties in plastics. It can withstand boiling hydrochloric acid, sulfuric acid, nitric acid and aqua regia, as well as strong alkalis and various organic solvents;
    2. Poor abrasion resistance and adhesion.     		1.-40℃~+130℃C(PTFE),
    -40℃~+160℃(PFA);
    2. Strong corrosive media such as acid and alkali;
    3. Sanitary media. 
    PO1. It can withstand hydrochloric acid, acetic acid, oxalic acid, ammonia, phosphoric acid, sulfuric acid, sodium hydroxide, and potassium hydroxide at room temperature.
    2. It can withstand concentrated alkali and various organic solvents.     		1. Below 70℃;
    2. General acid, alkali, and salt solutions;
    3. General water, sewage, mud, mineral slurry. 
    CeramicsWear resistance, high temperature resistance, corrosion resistanceBelow 200℃

    1.Environmental conditions:

    Magmeter flowmeter, especially the flowmeter with intelligent LCD screen. The installation position should avoid direct sunlight as much as possible. The ambient temperature should be between 5℃~55℃.

    2.Avoid strong interference sources

    Choose a place where there is no strong electromagnetic field radiation to install the flowmeter.

    Avoid devices that can easily cause electromagnetic interference, such as motors, transformers, and frequency converters.

    The measurement principle of the flowmeter is based on Faraday’s law of electromagnetic induction, the original
    The initial signal is very weak, less than millivolt.

    If there is strong electromagnetic field radiation near the flowmeter, it will affect the accuracy of the measurement and even fail to work normally.

    3.Magmeter straight run

    Pay attention to avoid eddy current generating parts as much as possible. Such as various valves, elbows, bypasses, etc.

    Try to extend the straight pipe section upstream and downstream of the flowmeter. Install a rectifier tube if necessary.

    Ensure that the upstream straight pipe section of the flowmeter must be at least 5 DN (measurement pipe diameter). The downstream is guaranteed to be more than 2 DN.

    4.The conductivity of the liquid must be uniform and stable

    Do not install the flowmeter in a place where the conductivity of the fluid to be measured is extremely uneven.
    If different media are injected upstream, the conductivity will be uneven and will affect the measurement.

    In this case, it is recommended to move the injection port downstream.

    If it must be injected from upstream, it should be as far away from the flowmeter as possible. Generally, it is better to keep a distance of more than 20 DN. To ensure that the liquid is fully mixed and uniform.

    5.Keep the electrode axis level

    The plane of the intermittent measuring electrode must be kept level. This prevents short-term insulation between the two electrodes due to air bubbles.

    6.Magmeter grounding rings

    Since the induction signal of the electromagnetic flowmeter is very weak, it is susceptible to noise. Therefore, the reference potential of the sensor and the converter must be the same as the measured liquid, and be grounded together.

    The purpose of installing grounding rings or grounding electrodes on both sides of the electromagnetic flowmeter is to establish the equipotentiality between the flowmeter casing and the liquid.

    Ordinary metal pipe (generally no need to install grounding ring)

    When the pipeline itself is well grounded, the grounding wire can be omitted, but the casing must be connected to the liquid through the grounding wire equipped with the flowmeter.

    Insulated pipes (plastic pipes, rubber-lined pipes, etc.)

    A grounding ring (or grounding electrode) should be installed at both ends of the sensor and the measured medium should be short-circuited with the earth through the grounding wire.

    Cathodic protection pipeline

    The pipe flanges are connected by copper wires, but they must be insulated from the grounding wire.

    Magnetic flowmeter is a widely used flow measuring instrument. How should we calibrate it?

    Let’s take a look at the calibration method of electromagnetic flowmeter:

    1. Determine the corresponding water pump according to the pipe diameter and flow rate of the verification test;
    2. After the flowmeter is correctly installed and connected, it should be energized and preheated for about 30 minutes in accordance with the requirements of the verification regulations;
    3. If the high-level tank water source is used, check whether the overflow signal of the stabilized water tower appears. Before the formal test, use the verification medium to circulate in the pipeline system for a certain period of time. At the same time, check whether there is any leakage in the sealing parts of the pipeline;
    4. The verification medium should be filled with the electromagnetic flowmeter sensor before the formal verification. Then the downstream valve should be closed to adjust the zero position;
    5. At the beginning of the verification, open the valve at the front of the pipeline and slowly open the valve behind the electromagnetic flowmeter to adjust the flow at the verification point.
    6. During the calibration process, the flow stability of each flow point should be within 1% to 2%-flow method. The total amount law can be within 5%.
      • The temperature change of the verification medium should not exceed 1℃ when the verification process of a flow point is completed. It should not exceed 5℃ when the entire verification process is completed.
      • There must be a sufficiently high pressure downstream of the electromagnetic flowmeter to be checked to ensure that no flashing and cavitation occur in the flow pipeline;
    7. After the test, close the valve at the front end of the test pipeline. Then stop the pump to avoid emptying the voltage stabilization facility. At the same time, the remaining verification medium in the test pipeline must be vented and the control system and the air compressor must be closed.

    Extended reading:
    What is the K-factor in a flow meter?
    Cryogenic Flow Meters|Liquid Nitrogen-Liquid Oxygen-LNG fluids

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    Magnetic flow meter pdf

    Electromagnetic flowmeter ManualDownload

    Frequently
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    Help Center

    A Rotameter flow meter is a variable area flow meter based on float position measurement. It is suitable for liquid and gas volumetric flow measurement and control.

    Read more: Rotameter flow meter working principle

    All electromagnetic flowmeters need to be calibrated when they leave the factory. Each finished product needs to pass the calibration line inspection before leaving the factory.

    It is to install the product on the assembly line. The front end adopts a strictly debugged standard table. A series of coefficients such as the diameter of the flowmeter, the damping coefficient, and the sensor coefficient of the electromagnetic flowmeter are set at the back end. To achieve the same flow rate as the standard meter.

    If calibration is done on-site, it may generally be used to calibrate outside the sealed pipeline. Such as portable ultrasonic flowmeter. But the accuracy is generally 0.5. If you just check it, you can use a portable ultrasonic flowmeter.

    Read more: Magnetic flow meter calibration

    Ultrasonic flow meters and electromagnetic flow meters have different measurement principles.

    Electromagnetic flowmeter must measure conductive liquid. The ultrasonic flowmeter can measure pure single-phase liquid. It has nothing to do with the conductivity of the liquid.

    The electromagnetic flowmeter must be in contact with the medium to measure. The ultrasonic flowmeter can do contact and non-contact measurement.

    The electromagnetic flowmeter is a flow measuring instrument. The measuring principle of the electromagnetic flowmeter is measured according to its principle of conduction. Most of the flow measurement on the market is solved by electromagnetic flowmeters.

    The electromagnetic flowmeter is a pure liquid volume measurement instrument.

    The mass flow meter is a function of fluid volume and fluid temperature and pressure. Is a dependent variable. The quality of a fluid is a quantity that does not change with time, space temperature, and pressure.

    Mass flow meters are compared with electromagnetic flow meters. It can measure non-conductive media. This is one of the biggest differences. In addition, the accuracy of the mass flow meter is higher. The cost is large, and there are fewer applications in the market.

    There is a big difference in the performance of general-purpose electromagnetic flowmeters on the market. Some have high precision and many functions. Some have low precision and simple functions.

    The basic error of the instrument with high accuracy is (±0.5%～±1%)R.
    The instrument with low accuracy is (±1.5%～±2.5%)FS.
    The price difference between the two is 1 to 2 times.

    Extended reading: Orifice Plate Flow Meter

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    Magnetic flow meter manufacturers

    Sino-Inst is one of the reliable Magnetic flow meter manufacturers and suppliers in China. Magnetic flow meters apply for wastewater flow rate measurement.

    Sino-Inst can offer stainless steel magnetic flow meters, both the Pipeline and plug-in style. Of course, Sino-Inst can offer you with the mass flow meters and other flow meters.

    Sino-Inst will offer you Magnetic flow meters with the Best Price. Reference price, $300-400/piece, DN10-DN2000. For special measuring media, we offer special lining materials: F4, F46, Fs, neoprene, urethane rubber, etc.

    Sino-Inst offer over 20 Magnetic flow meters, with Best Price. A wide variety of Magmeters options are available to you, such as free samples, paid samples.

    About 40% of these are magnetic flow meter, 30% are Insertion Magnetic Flow Meter, 30% are sanitary flow meters. Magmeters products are most popular in North America, Mid East, and Eastern Europe.

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

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

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