HH3151 HART Pressure Transmitter

HART pressure transmitter is the smart pressure transmitter in the process industry. With 4-20mA, HART. So, you can calibrate your pressure transmitters with HART communicators.

HART pressure transmitter configured through distributed control system (DCS) or HART communicator. The HART pressure transmitter is compatible with the Highway Addressable Remote Transmitter (HART) communication protocol. The HART function can transmit pressure transmitter data through an AC digital signal. The AC digital signal uses a 4-20mA analog output signal as a carrier. This eliminates the need for additional wires and connectors.

HH3151 HART Smart pressure transmitter that provides simplified field change, while communicating asset management data utilizing the latest HART 7 specification.

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

Features of HART pressure transmitter

HART pressure transmitter is a complete product line of liquid level, differential pressure, gauge pressure and absolute pressure transmitter. Models include flushing diaphragms and sanitary flanges for liquid level measurement, hydrostatic tank metering – HTG. And wetted parts of various materials to suit the process requirements.

3151 HART pressure transmitter
  • All models can be supplied with various remote seals.
  • Update output current in 100 ms with 0.75 µA/bit resolution;
  • Improved performance due to dedicated math co-processor;
  • Multi-drop operation mode;
  • PID control function;
  • Supports DTM and EDDL;
  • Bi-directional flow measurement;
  • With FMEDA analysis and MTBF of 244 year.

What is a HART transmitter?

HART transmitters are much more complicated.
The HART transmitter has the same pressure input and 4-20 mA output. But it also has an analog current loop output. The device contains some digital variables and settings. Access to these digital parameters requires the use of a HART configurator or communicator. This is essential for maintaining these devices.
Just like Hart Communicator 375.
In fact, many HART devices, cannot be maintained without access to digital parameters.

You may like: Verabar Flow Meter

What is HART calibrator?

HART calibrator is our HART communicator for calibrating instruments. For example pressure transmitter, DP transmitter, liquid level transmitter, flowmeter, and temperature transmitter.
HART communication protocol (Highway Addressable Remote Transducer) is a hybrid analog + digital industrial automation open protocol.
Its most significant advantage is that it can communicate through the traditional 4–20 mA analog instrument current loop, sharing only a pair of wires used by the analog host system.
We use this protocol in the HART calibrator.

HART communicator (such as HART 475) is the most common HART calibrator.
The proprietary calibration process ensures optimal temperature compensation. This limits the thermal impact on the sensor output.
It is suitable for the global process control industry. It provides a cost-effective solution for the use of conventional HART transmitters (such as the HART 475 field communicator).

HART protocol

What is HART pressure transmitter?

HART pressure transmitters

HART pressure transmitter for configuration via distributed control system (DCS) or HART communicator.

The HART pressure transmitter is compatible with the Highway Addressable Remote Transmitter (HART) communication protocol. This protocol is the most popular standard used by intelligent field devices and is used by the process control industry.
The HART function can transmit pressure transmitter data through AC digital signals. It uses 4-20mA analog output signals as a carrier. There is no need for additional wires and connectors.

HART pressure transmitter can also be used with a paperless recorder.

How to calibrate HART pressure transmitters

A pressure transmitter is one of the most common instruments in a process plant. To assure its accuracy, it needs to be calibrated.

But what do you need to calibrate it and how is it done?

You may know how to calibrate a pressure transmitter? Or, how to calibrate a differential pressure transmitter? Then, calibrate HART pressure transmitters, kind of like pressure transmitter calibration using a hart communicator. Pressure transmitter manufacturers have improved accuracy and technology, designed into these smart pressure measurement devices.

To calibrate a pressure transmitter, you need:

loop supply (if not connected to the controls system’s loop supply);
a pressure generator to generate input pressure;
an accurate calibrator to measure the input pressure;
an accurate calibrator to measure the output mA current.

Typically, the pressure transmitter is a HART protocol transmitter. So in case, there is any need to adjust/trim it, you will need to use a device supporting HART communication.

How to calibrate HART pressure transmitters?

Explaining how to do the calibration would result in quite a long text. So we have put together a video for you instead. The video shows you how to calibrate and trim a HART pressure transmitter. Please have a look at the video: How to calibrate HART pressure transmitters

Video source: https://www.youtube.com/watch?v=4wLCqH0M9fU&t=9s

HART Pressure Transmitters Calibration Steps

How to calibrate HART pressure transmitters?

Total Time:

1. Isolate the transmitter from the process being measured and its loop wiring.

2. If measuring the mA signal across the transmitter test diode leave the wires intact, but note this method does not give the best mA measurement accuracy.

3. Connect the mA measurement jacks of the 754 to the transmitter.

4. Connect the pressure module cable to the 475, and connect the transmitter test hose from the hand pump to the transmitter.
Press the HART button on the calibrator to see the configuration of the transmitter.

5. Press HART again and the calibrator will offer the correct measure/source combination for the test.

6. If documenting the calibration press As-Found, input the test tolerance and follow the prompts.

7. If the measured mA signal at the test points is found within tolerance the test is complete.
If not, change is required.
Select, adjust, and trim the pressure zero, mA output signal and input sensor.

If you still do not know, how to check the pressure transmitter?  Or, how to calibrate a pressure transmitter.

Just contact us.

HART pressure transmitter working principle

HART pressure transmitter is one type of smart pressure transmitter.

HART pressure transmitter connection

Principle and Application of Diffusion Silicon Pressure Transmitter

The pressure of the measured medium directly acts on the diaphragm of the sensor (stainless steel or ceramic). Causing the diaphragm to generate a micro-displacement proportional to the pressure of the medium. The resistance value of the sensor changes. The electronic circuit detects this change and converts and outputs a standard measurement signal corresponding to this pressure.

Principle of capacitive pressure transmitter

The capacitive pressure transmitter is mainly composed of a capacitance sensor and circuit board. The sensor implements pressure-capacitance conversion. The circuit board converts the capacitance to a two-wire 4-20mA. When the process pressure is applied to the isolation diaphragm from both sides (or one side) of the measuring chamber, it is transferred to the central diaphragm of the chamber through the silicone oil filling liquid. The central diaphragm is a diaphragm with tensioned edges. Under the action of pressure, a corresponding displacement is generated. This displacement creates a change in differential capacitance! And through the adjustment, oscillation, and amplification of the electronic circuit board! Converted into 4-20mA signal output! The output current is directly proportional to the process pressure!

pressure transducer often called a pressure transmitter, is a transducer that converts pressure into an analog electrical signal.

Although there are various types of pressure transducers, one of the most common is the strain-gage base transducer.

The conversion of pressure into an electrical signal is achieved by the physical deformation of strain gauges, which are bonded into the diaphragm of the pressure transducer, and wired into a Wheatstone bridge configuration.

Pressure applied to the pressure transducer produces a deflection of the diaphragm, which introduces strain to the gages.

The strain will produce an electrical resistance change proportional to the pressure.

In general, a pressure transmitter consists of three main components: a pressure sensor, a measuring circuit, and a process connection.

The main function of the pressure transmitter is to convert the physical parameters of the gas, liquid and other physical parameters of the pressure sensor into a standard electrical signal.

The standard electrical signal is more convenient for indicating the alarm device, the adjusting device, the recorder, and the secondary instrument.

Read more about Pressure Transmitter Working Principle

HART Smart Explosion Proof Pressure Transmitter

HART Explosion-proof pressure transmitters are available in a wide range of specifications. Easy to install and use, safe and explosion-proof.

They can be used in petrochemical, electric power, metallurgy, pharmaceutical, food processing, and other industries. Products follow the “IEC” standard. And explosion-proof pressure transmitters are renowned.

The company’s high-precision, high-stability pressure sensor assembly, through high-reliability amplifier circuit. And precision temperature compensation. The absolute or gauge pressure of the measured medium is converted into: 4 ~ 20mA, 0 ~ 5VDC, 0 ~ 10VDC and 1 ~ 5VDC,
and other standard electrical signals.

High-quality sensors hermetically sealed soldering technology and a complete assembly process, ensure excellent quality and performance.

Explosion-proof pressure transmitters are used in the following industries:

  • Compact explosion-proof pressure transmitter
  • Compact explosion-proof pressure transmitter
  • Industrial site process pressure detection
  • Laboratory pressure calibration system
  • Navigation and shipbuilding Aviation and aircraft manufacturing
  • Air separation equipment and thermal power unit
  • Energy management system
  • Hydraulic and pneumatic measurement and control system

You may like: Turbine flow meters | Magnetostrictive level sensor| Coriolis mass flow meter

What are differential pressure transmitters?

Differential pressure (DP) transmitter, also called differential pressure transducer. Differential pressure transmitters measure the difference between two pressures. Sino-Instrument supplies Differential Pressure Transmitters For differential pressure measurement.

Differential Pressure Transmitters
For differential pressure measurement
pressure ranges 0 … 1 mbar up to 0 … 70 bar

Extended reading: Smart Differential Pressure Transmitter

Sino-Instrument offers over 10 hart Transducers. About 50% of these are 4-20ma Low-Pressure Transducers, 40% are Differential Pressure Gauge, and 20% are Diaphragm Seal Pressure transmitters, 20% are 4-20ma differential pressure transmitters.

Sino-Instrument sells through a mature distribution network that reaches all 50 states and 30 countries worldwide. HART Pressure Transmitter 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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More featured products

Diaphragm Seal Pressure Transmitter

Diaphragm seal pressure transmitter, with flange connection, direct mount. Diaphragm seal systems protect pressure transmitters from hot, viscous, contaminated, or corrosive media.

Diaphragm seal pressure transmitter with flange direct mount. Diaphragm seals, also known as chemical seals or flush seals. Diaphragm seals work with pressure transmitters, pressure gauges. To prevent the process medium from entering into the pressure-sensing assembly. So, Diaphragm seal systems protect pressure transmitters from hot, viscous, contaminated, or corrosive media. Diaphragm seal connection can work with the capillary, flange, and manifold. Like remote seal pressure transmitter, DP level transmitter.

Sino-Inst offers a variety of Diaphragm Seal Pressure Transmitters for industrial pressure measurement. If you have any questions, please contact our sales engineers.

Features of Diaphragm seal pressure transmitter

  1. Diffusion silicon isolation sensor
  2. Flange installation
  3. Large size diaphragm, fully welded and sealed, long-term reliable and durable
  4. Aluminum alloy junction box with strong seal and good outdoor installation
  5. Used for pressure measurement of gas, liquid and steam
  6. Anti-corrosion metal diaphragm optional
  7. With LCD display optional
  8. Especially suitable for high temperature or viscous liquid
  9. The flange size is customized according to customer requirements. And the installation is flexible and diverse

Read more about Steam pressure transmitter-Pressure measure on steam pipeline 

Specifications of Diaphragm Seal Pressure Transmitter

ModelTransmitter type
SI-1305Flange level transmitter
CodeScale range
2 3 4 50-20~100kPa(0-2000~10000mmH2O)
CodeOutput form
ELinear output 4-20mAdc
SFLinear output 4-20mAdc+HART signal,Full function buttons on site
FMODBUS-485 signal
CodeFlange standard (high pressure side flange)
AANSI American Standard (HG20615)
DDIN European standard(HG20592)
CodeProcess connection size
ANSI American Standard (HG20615)DIN European standard(HG20592)
CodeProcess connection withstand voltage rating
ANSI American Standard (HG20615)DIN European standard(HG20592)
CodeMeasuring diaphragm
A316 Stainless steel
BHastelloy C
FSpecial requirements
CodeInsert barrel lengthInsert barrel material
A0 mmNone
B50 mm316L Stainless steel
C150 mm316L Stainless steel
D200 mm316L Stainless steel
CodeFilling liquid
DOrdinary silicone oil  (-40~104℃)
FHigh temperature silicone oil   (-40~304℃)
SInert liquid  (-40~204℃)
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
CodeOptional parts
M10~100%  Linear indicator
M4LCD Multi-function digital display
DaFlameproof  ExdIIBT5Gb;(explosion-proof certificate No. : CE16.1163)
FaIntrinsically safe ExiaIICT4 / T5 / T6Ga;(explosion-proof certificate No. : CE15.2354X)
CXWith corresponding 316 flushing ring

You may like: Explosion Proof Pressure Transmitter for Hazardous locations

Applications for Diaphragm Seal Pressure/ Differential Pressure Transmitters

The application which is suitable for diaphragm seal system… For measuring the liquid level, density, flow, and pressure of :

  • high/low temperature fluids
  • highly corrosive/high viscosity fluids
  • the fluids which may cause clogging of impulse piping in the low temperature
  • toxic fluids
  • the fluids containing suspended solids which are deposited in the impulse piping and may cause clogging.\

Extended reading: Featured Diaphragm Seal Pressure Transmitters

What are the application considerations for diaphragm seals?

The biggest advantage of the diaphragm pressure transmitter is that different diaphragm materials can be selected. According to different corrosion, media to achieve the best corrosion resistance. The commonly used diaphragm materials are SUS316L stainless steel. Tantalum, Hastelloy, Monel, Pure titanium, F4, etc. 

When choosing a diaphragm pressure transmitter, in addition to the correct choice of structure and range, the more important thing is to choose the material. The so-called reasonable is to consider its corrosion resistance, but also to consider the economy. For example, the corrosion resistance of the tantalum diaphragm and Hastelloy is excellent, but it is expensive. Only used in environments with high corrosivity and other cheap materials are not suitable.

The following table introduces several common corrosion-resistant materials that can be selected for corrosion media. For your reference.

Corrosive mediumTin bronze (QSn6.5-0.4)SUS316Pure tantalum (Ta)Monel (Ni70Cu30)Hastelloy (HC)Polytetrafluoroethylene (F4)
Sulfuric acid (H2SO4)VVVV
Nitric acid (HNO3)VVV
Hydrochloric acid (HCI)VV
Phosphoric acid (H3PO4)VVVVV
Acetic acid (CH3COOH)VVVV
Caustic soda (NaOH)V
Soda ash (Na2CO3)VV
Baking soda (NaHCO3)VV
Chlorine (CI)Dry: VDry: VDry: VVV
Wet: ╳Wet: ╳Wet: ╳
Bromine (Br2)Dry: △Dry: ╳Dry: ○V
Wet: ╳Wet: △Wet: ╳
Ammonia (NH3)VV
Seawater (30% NaCI)VVV
Explanation of symbols: ○ ——best; △ ——conditional use; V——can be used;

Extended reading: Common Pressure Sensor Applications

What is diaphragm seal pressure transmitter?

The diaphragm seal pressure transmitter is the flange type pressure transmitter. This type of pressure transmitter, assembling diaphragm seals to field transmitters for the purpose of measuring pressure, differential pressure, level, and flow.

What is a diaphragm seal?

Diaphragm Seals, also known as Chemical Seals or Gauge Isolators, are used to isolate pressure instrumentation, like pressure gauges, pressure transmitters, pressure switches, level transmitters, and more from process media that is hot, corrosive, clogging, or otherwise damaging to the pressure instrument.

A diaphragm seal has two primary tasks:

  1. Separation of the measuring instrument from the process medium
  2. Transfer of the pressure to the measuring instrument

You may like: Diaphragm pressure gauge

What is remote seal?

The remote seal is used to prevent the medium in the pipeline from directly entering the pressure sensor assembly in the pressure transmitter. It is connected to the transmitter by a capillary filled with fluid. As a result, they’re often used in refining, petrochemical, and chemical plants.

Extended reading: SI-703 Flush Diaphragm Pressure Sensor

What are the advantages of diaphragm seals?

Diaphragm seals offer the advantage that the “contact surface” between pressure medium and diaphragm is relatively large. Thus ensuring accurate pressure measurement, especially for very low pressures (< 600m bar). Furthermore, they can be easily dismounted, e.g. for cleaning or calibration purposes.

How do diaphragm seals work?

Basically, diaphragm seals are used in all pressure measurement processes to avoid direct contact between the measuring instrument and the medium during this process. In addition, if the measuring point cannot be installed or read because the measuring point is located in a hard-to-reach location, a diaphragm seal can also be used. In both cases, the applied pressure is transferred to the measuring instrument through the system fill fluid in the diaphragm seal housing.
The diaphragm of the seal can be made of different materials, such as stainless steel, Hastelloy, Monel, or tantalum. In addition, coatings with ECTFE, PFA, or gold can also be used.

We can provide the best diaphragm seal design, materials, system fill fluid, and accessories for each application. The combined configuration of the pressure measuring instrument and the diaphragm seal is mainly determined by the special application conditions of the diaphragm sealing system.

How does a diaphragm pressure sensor work?

When the diaphragm seal pressure transmitter is working, the high and low-pressure side isolation diaphragms and the filling liquid transfer the process pressure to the center filling liquid. The filling fluid in the center transmits the pressure to the sensing diaphragm in the center of the δ-chamber sensor. The sensing diaphragm is a tensioned elastic element and its displacement changes with the differential pressure. For GP gauge pressure transmitters, the atmospheric pressure is applied to the low-pressure side of the sensing diaphragm. AP absolute pressure transmitter, the low-pressure side always maintains a reference pressure. The maximum displacement of the sensing diaphragm is 0.004 inches (0.10 mm). The displacement is proportional to the pressure. The two capacitance fixed plates of the measuring diaphragm are linearly converted into a 2-wire current, voltage, or digital HART output signal of 4-20mADC by the amplifying circuit.

Extended reading: How to calibrate HART pressure transmitters

Rosemount 1199 Diaphragm Seal System

Rosemount 1199 remote transmission diaphragm system provides the world’s most extensive product variety and specifications to meet the requirements of various measurements and applications.

There are the following types of remote transmission differential pressure/level transmitters:
1) PFW flat type remote transmission device
2) RTW thread installation type remote transmission device
3) EFW inserted barrel remote transmission device
4) RFW flange mounted remote transmission device
5) SCW hygienic remote transmission device

The 1199 remote diaphragm can be assembled to Sino-Inst differential, gauge, and absolute pressure transmitters and liquid level transmitters.

We can learn more about the 1199 remote diaphragms.

Techincal Support

Steam Pressure Transmitter

Steam pressure transmitters are widely used in the measurement and control of various high-temperature steam piping…

Cryogenic Pressure Transducers

Cryogenic pressure transducer for low temperature pressure measurement.  -196℃~+125℃、-260℃/-350c(especial). Sino-Inst offers a variety of Pressure Sensors…


The purpose of the diaphragm seal is to protect expensive instruments. Its job is to transfer the pressure of the process medium through the membrane seal to the filling fluid and then transmit the resulting pressure wave to a pressure gauge or sensor at the head of the measuring assembly.
Choose a suitable diaphragm seal filling liquid.
The characteristics of the diaphragm seal fill fluid determine the performance of the sealing system to a large extent. Both in response time and temperature dissipation conditions.
The initial consideration in choosing a sealed diaphragm to fill fluid is the media compatibility of the process. The temperature and pressure of the process medium are also important factors because all the filling fluid expands or contracts with changes in temperature.
Remember that there is a direct relationship between the measured response time of the viscosity and the density of the filling fluid. More viscous filling fluids lead to longer response times.
In addition, the filling fluid with a higher density can have an impact on the mounting.
Types of filling fluid: glycerin, silicone oil, and halogenated carbon are the most commonly used sealing diaphragm filling fluids.

Extended reading: Flat Pressure Sensor for High Viscosity Fluids

Diaphragm seals are mounted to existing connecting flanges or welding sockets, which are welded to a pipeline, a process reactor, or a tank.

Extended reading: extrusion melt pressure transducer

A diaphragm seal can be mounted via a direct connection, a cooling element or a capillary.

Besides pressure sensors, we also supply torque sensors. What Is a Torque Transducer? How to Choose?

The combinations of diaphragm seals with flange connections can be used for processes with extreme temperatures and with aggressive, adhesive, corrosive, highly viscous, environmentally hazardous or toxic media. With its connection dimensions, the flange-type diaphragm seal is suitable for all currently used standard flanges and is mounted in lieu of a blind flange.

Extended Reading: Resistive Pressure Transducer

Diaphragm-sealed pressure transmitters are used when the medium is corrosive or will corrode the internal parts of the transmitter (for example, ammonia will corrode the copper in the transmitter).

Extended reading: High accuracy pressure transducers

The measurement accuracy of flat film and convex film is the same, but there is a difference in the measurement structure.
The choice of the two types of diaphragms is mainly based on the different applications.
For example, in regular occasions, the material is easy to flow and not easy to crystallize and block. Just use a flat diaphragm.
If the measuring medium is easy to crystallize and block, consider the convex diaphragm structure. Of course, we must also consider the installation and pressure pipe issues.

Sino-Instrument is a pressure transmitters manufacturer in China.

We offer all types of Diaphragm Seal Pressure Transmitters. Like Direct Mounted, flange-mounted, single flange, double flange, Remote Diaphragm SealsHigh Static, Digital Remote.

Most of our Diaphragm Seal Pressure Transmitters are used in oil, liquids, DP transmitterflow measurementlevel measurement (like the ultrasonic level measurement), density, and other process variables.

Diaphragm Seal Pressure Transmitters are generally available with three types of electrical output; millivolt, amplified voltage, and 4-20mA.

You can ensure product safety by selecting from certified suppliers, with ISO9001, ISO14001 certification. We will share more about instrument calibration, like the flow transmitter calibration.

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HHXA-EJA210E Flange Mounted Differential Pressure Transmitter

Flange Mounted Differential Pressure Transmitter is also called single flange DP level transmitter. For liquid, gas or vapor pressure measurement.

Flange Mounted Differential Pressure Transmitter also called DP level transmitter/pressure level transmitter. The smart differential pressure transmitter/pressure transmitter is provided with a diaphragm seal. Realize the measurement of liquid level. 4-20mA output. Flange Mounted Differential Pressure Transmitter is flange mounted. The isolation diaphragm is very thin and is a weak link in corrosion resistance. So, the material of the wetted diaphragm is 316L, Hastelloy C-276, Monel, tantalum. Suitable for anti-corrosion requirements in different situations. It can be reasonably selected according to the measured medium concentration, humidity, pressure, and other parameters.

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

HHXA-EJA210E Flange Mounted Differential Pressure Transmitter Description:

The high-performance flange mounted differential pressure transmitter HHXA-EJA210E can be used to measure levels of densities of solidifying or precipitating liquids. The HHXA-EJA210E single-flange differential pressure transmitter can also communicate with the HART275/475 Communicator to set and check it. Outputs a 4 to 20 mA DC signal, corresponding to the measured differential pressure. HHXA-EJA210E single flange differential pressure transmitter uses advanced micro-processing technology and digital communication technology. Besides all the functions of conventional intelligence. It also has a series of enhanced functions. Such as zero-point automatic adjustment, remote local control parameter viewing, and adjustment control parameter password lock. At the same time, remote parameter setting, remote control, self-diagnosis, and other functions are performed through the Fieldbus HART protocol.

The HHXA-EJA210E is the Flange-mount Liquid Level Transmitter in the H&HXA-EJA series. Rosemount 3051 and Yokogawa EJA functional alternatives. We also supply an SMT3151LT Differential pressure level transmitter for level measurement.

Extended reading: How to calibrate HART pressure transmitters

HHXA-EJA210E Flange Mounted Differential Pressure Transmitter Features:

The single flange level gauge is an extension and development of the pressure transmitter technology. According to the principle that the pressure generated by the liquid of different specific gravity at different heights has a linear relationship. The realization of the volume, liquid height, water, oil and paste Accurate measurement and transmission of weight.

  1. Innovative indication, intuitive reading and eye-catching. The direction of the observation indicator can be changed according to user needs.
  2. The structure is simple: there are no movable or elastic elements. Therefore, the reliability is extremely high. The amount of maintenance is very small.
  3. Easy installation: the built-in structure especially shows this feature. No special tools are required.
  4. Convenient adjustment: the two potentiometers of zero position and range can arbitrarily carry out zero point migration or range change within the effective range of liquid level detection. The two adjustments do not affect each other.
  5. Widely used: It is suitable for liquid level measurement of high temperature, high pressure, strong corrosion and other media.
  6. Large measuring range. Not limited by the height of the storage tank.
  7. The indicator mechanism is completely isolated from the measured medium. It has good sealing, high reliability and safe use.
  8. With intrinsically safe explosion-proof and isolation explosion-proof capabilities. Can be used in various hazardous locations
  9. With anti-blocking design, it can measure the liquid level of the pasty medium.
  10. Fine and unique zero point, full range, non-linear compensation. To ensure the accuracy of the instrument within the scope of use conditions, long-term stability.

Extended reading: Smart Differential Pressure Transmitter

HHXA-EJA210E Flange Mounted Differential Pressure Transmitter images

Specification of Yokogawa HHXA- EJA210E Flange Mounted Differential Pressure Transmitter

ModelTransmitter type
HHXA- EJA210Flange liquid level transmitter
CodeScale range
CodeOutput form
ELinear output 4-20mAdc
SFLinear output 4-20mAdc +HART signal
FMODBUS-485 signal
CodeFlange standard (high pressure side flange)
AANSI American Standard (HG20615)
DDIN European Standard (HG20592)
CodeProcess connection size
ANSI American Standard (HG20615)DIN European Standard (HG20592)
CodeProcess connection pressure rating
ANSI American Standard (HG20615)DIN European Standard (HG20592)
CodeHigh pressure side diaphragm
A316 stainless steel
BHastelloy C
FSpecial Requirements
CodeHigh pressure side insert tube lengthHigh pressure side insert cylinder material
A0 mmNone
B50 mm316L Stainless steel
C150 mm316L Stainless steel
D200 mm316L Stainless steel
CodeHigh pressure side filling fluid
DGeneral silicone oil  (-40~104℃)
FHigh temperature silicone oil   (-40~304℃)
SInert liquid  (-40~204℃)
Low pressure side structural materialFlange (joint)Exhaust/drain valveIsolation diaphragmSensor filling fluid
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 C Silicone oil
35Hastelloy CHastelloy CTantalum Silicone oil
44MonelMonelMonel Silicone oil
S2A remote transmission device (with a remote transmission device on the low-voltage side)
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
CodeOptional parts
M10~100%  Linear indicator head
M4LCD multi – power digital display head
D1Side discharge valve at the top (only for the low pressure side of the low pressure side without remote transmission)
D2Side discharge valve at the top (only for the low pressure side of the low pressure side without remote transmission)
DaFlameproof  ExdIIBT5Gb;(explosion-proof certificate no. : CE16.1163)
FaIntrinsically safe ExiaIICT4 / T5 / T6Ga;(explosion-proof certificate no. : CE15.2354X)
CXWith corresponding 316 flushing ring

Extended Reading: Smart pressure transmitter working principle

The high performance flange mounted differential pressure transmitter EJA210E, can be used to measure levels of densities of solidifying or precipitating liquids.
EJA210E outputs a 4 to 20 mA DC signal, corresponding to the measured differential pressure.
Its accurate and stable sensor can also measure the static pressure, which can be shown on the integral indicator. Or monitored via BRAIN or HART communications.
Other key features include quick response, remote set-up using communications and self-diagnostics. FOUNDATION Fieldbus and PROFIBUS PA protocol types are also available.
All EJA-E series models in their standard configuration, except for the Fieldbus and PROFIBUS types, are certified as complying with SIL 2 for safety need.

Read more What is a diaphragm seal?


The single-flange pressure / level transmitter can accurately measure the liquid level and density of various containers. There are two types of flat flange and plug-in flange. It is suitable for high viscosity medium or suspended liquid measurement.

  1. Viscous medium at high temperature;
  2. Easily crystallized medium;
  3. Precipitation medium with solid particles or suspended matter;
  4. Strongly corrosive or highly toxic medium;
  5. It can eliminate the leakage of the pressure guiding pipe and pollute the surrounding environment. It can avoid the instability of the measurement signal when the isolation liquid is used. The tedious work of frequently supplementing the isolation liquid is required;
  6. Continuously and accurately measure the interface and density;
  7. The remote transmission device can avoid the mixing of different instantaneous media, so that the measurement results truly reflect the actual situation of process changes;
  8. Places with high sanitation requirements;
  9. Such as in the production of food, beverage and pharmaceutical industries. Not only the transmitter contacting the media parts meet the hygienic standards, but also should be easy to wash. To prevent cross-contamination of different batches of media.

Pressure level transmitter is good for level measurement. Most of the time, we use submersible hydrostatic level sensor for the level measurement. When you can not use the probe of hydrostatic level sensor, you can try with this pressure level transmitter. Pressure level transmitter, is one type of DP level measure instrument, with the diaphragm.


SMT3151LT Differential pressure (DP) level transmitter a new type of differential pressure (DP) transmitter produced by advanced technology and equipment. Continuous level, flow and differential pressure measurement. Liquid level measurement, is the most common measurement process in continuous production processes, such as: petroleum and chemical industry. The liquid level measuring instrument currently widely used, is the differential pressure level transmitter.


Working principle of Smart differential pressure transmitter

1. Head cover 2. Head 3. Metal bulkhead 4. Shell 5. Nameplate label 6. Explosion-proof joint 7. Terminal block 8. Head cover 9. Drain valve 10. Bolt 11. Clamp 12. Sensor seal 13. Sensor 14. Nut 15. Welded pipe joint assembly

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 transmittersdifferential pressure level transmitter working principle

Single flange. VS. Double flange differential pressure level transmitter

  1. In principle: all are differential pressure transmitters + flange guide pressure;
  2. In terms of structure: the single flange liquid zd position transmitter has only one flange diaphragm box connected to the high pressure side, and the low pressure side to the atmosphere. The double flange liquid level transmitter is high and low pressure side through oil-filled capillary It is connected with two flanged membrane return boxes. There is also a capillary. The single flange transmitter is installed below, and a capillary is drawn from the low pressure side of the single flange transmitter to the upper flange membrane box.
  3. In terms of engineering applications: all can only measure the liquid level of fixed density. The single-flange transmitter can only be used for the liquid level of atmospheric equipment that can be imagined with the atmosphere. The double-flange transmitter can be suitable. Answer: Use closed equipment kettle to measure liquid level;
  4. From the economical point of view, the double flange is definitely more expensive than the single flange. After all, there is one more flange capsule and capillary.

How to choose flange type liquid level transmitter?

Flange level transmitters often require special environmental processing during production. Requires small range and high accuracy. Flange level transmitters are also required to withstand high temperature, corrosion resistance and high overload withstand capability. Therefore, the scope of application must be clearly defined when selecting the flange type liquid level transmitter.

When choosing a flange-type liquid level transmitter, the following factors are mainly considered:

  1. The measurement object, such as the physical and chemical properties of the measured medium. And working pressure and temperature, installation conditions, speed of liquid level change, etc .;
  2. Measurement and control requirements. Such as measurement range, measurement accuracy, display method. On-site instructions, long-distance instructions, interface with computer, safety and anti-corrosion. Reliability and construction convenience.

When selecting a double-flange differential pressure transmitter, a very important factor must be paid attention to is the differential pressure level transmitter. It is installed at the bottom of the liquid container. The height of the liquid level is reflected by the gauge pressure signal. In the control process of liquid level measurement in the pharmaceutical and chemical industries. The container holding the liquid is often under pressure. At this time, the conventional static pressure liquid level transmitter cannot meet the measurement requirements. Due to improvements in the sensor circuit and structure. Improve the practical value of differential pressure liquid level measurement technology in the pharmaceutical and food industries.

Piezoresistive Differential Pressure Transmitter
Piezoresistive Differential Pressure Transmitter utilizes the piezoresistive effect of semiconductor silicon materials. Realize accurate measurement of differential pressure.
Smart Differential Pressure Transmitter
Smart Differential Pressure Transmitter measures industrial differential pressure. Can Works with diaphragm seals, capillary, HART. Outputs standard signals (such as 4 ~ 20mA, 0 ~ 5V).
Diaphragm Seal Pressure Transmitter
When the process medium should not come into contact with the pressured parts of the measuring instrument. Diaphragm sealed pressure transmitters are used for pressure measurement.
High-Temperature Pressure Transmitter
High-temperature pressure transmitters with a 4-20mA output.
which has a temperature capability of over 850 °C and is not pyroelectric.

Sino-Instrument is one of the most excellent DP transmitters, pressure transmitters and level transmitters suppliers. Sino-Instrument can offer you a complete solution of pressure transmitter.

We all know that the Yokogawa EJA210E Flange Mounted Differential Pressure Transmitter, which commonly used in liquid, gas or vapor pressure measurement.

Sino-Instrument can offer you with HHXA-eja110e\ HHXA-eja530e \ HHXA-eja210a\ HHXA-jx210a. Our transmitters can work for you just like yokogawa level transmitters.

To know how the HHXA-EJA210E can help you Boost your bottom line.

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