Remote Seal Differential Pressure Transmitter

Remote seal differential pressure transmitter is used to prevent medium from entering transmitter. The pressure sensitive diaphragm and the transmitter are connected by a capillary filled with fluid. It is used to measure the level, flow and pressure of fluids, gases or steam.

Remote Seal Differential Pressure Transmitter is often used as a tank level transmitter. The smart pressure transmitter is connected with a stainless steel flange by capillary. The pressure is sensed by a remote transmission device installed on a pipe or container. The pressure is transmitted to the body of the transmitter through the filling silicone oil in the capillary. Then The delta chamber and the amplifying circuit board in the main body of the transmitter convert 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.

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.

Features of Remote Seal Differential Pressure Transmitter

  1. Simulate the “online operation” assessment one by one. Ensure that the transmitter works stably and reliably under the extreme ambient temperature, medium temperature and working pressure (including positive pressure or vacuum).
  2. Adopt “dynamic profile” remote transmission diaphragm structure. The diaphragm will not be damaged after overload. The accuracy will not change after long-term work.
  3. The filling system with full fusion welding and rigid sealing structure is selected to eliminate the occurrence of oil leakage.
  4. Novelly designed capillary coupling parts. Capillary is reliably protected. It is not easy to break when used on site.
  5. Variety, form and size of remote transmission device. And a variety of filling liquid types. It can meet the measurement needs of various occasions.
  6. Various special products can be provided. Including high temperature, high vacuum, fast response and unequal length capillary (length ≤ 3 meters) remote transmission pressure transmitter

Specifications of Remote Seal Differential Pressure Transmitter

Output signal:4 ~ 20MA. DC two-wire system (analog) superimposes the digital signal on the two-wire 4 ~ 20mA DC signal, and the user selects linear or square root output.
Power supply:12 ~ 45V.DC;
Load characteristics:
Power supply impact: <0.005% output range / V;
Load effect: when the power supply is stable, there is no load effect;
Measurement accuracy: ± 0.1% of the adjustment range, ± 0.2% standard accuracy is ± 0.2%, if other accuracy is selected, please indicate when ordering and selecting;
Range ratio: 10: 1 or 100 to 1;
Resistance: usually adjustable from 0.1 to 16 seconds, when inert liquid is filled or with a remote transmission device, the time constant will increase;
Startup time: <2 seconds, no warm-up is required.

Working environment:
ambient temperature -29 ~ 93 ℃ (analog amplifier);
29 ~ 75 ℃ (digital / smart amplifier);
-29 ~ 65 ℃ (with display meter);
Ambient humidity 0 ~ 95%.
Protection characteristics:protection ability IP65;
Explosion-proof type: Flameproof Ex d II BT4-6;
Intrinsically safe Exia II CT5.
The effect of static pressure: Zero error: ± 0.5% zui large range limit, for 32MPa under pipeline pressure by zero adjustments.
Electromagnetic radiation effect:0.05% large range value, receiving radiation frequency 27 ~ 500MHz, test field strength 3V / m.
Indication table (%):LCD digital display accuracy ± 0.2%.
Vibration effect:± 200% / g when vibrating at 200Hz in any direction.
Installation position: The diaphragm is not installed vertically, and a zero error of less than 0.24KPa may occur, but it can be corrected by zero adjustment.
Weight: 3.9Kg (excluding accessories).

Note:
① The working pressure of the remote pressure transmitter also depends on the specifications of the selected flange.
② The working temperature of the remote transmission device is determined by the type of filling liquid selected.
③ The remote transmission pressure transmitter refers to the output change produced by the temperature of the remote transmission device on one side.
④ The effects of static pressure and temperature are measured during a large range.
⑤ The length of the capillary on the side of the GP remote pressure transmitter is generally 1.5 meters, and the length should not exceed 3 meters (special agreement is agreed).

Read more What is a diaphragm seal?

DP Remote Seal Pressure Transmitter with Diaphragm Seal Installation

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 1199 remote diaphragm.

Read more about: Differential Pressure Transmitter Installation Guide

Applications of Remote Seal Differential Pressure Transmitter

Remote Seal Differential Pressure Transmitter is a pressure sensor assembly used to prevent the medium in the pipeline from directly entering the transmitter. It is connected to the transmitter by a capillary filled with fluid. It is used to measure the liquid level, flow rate and pressure of liquid, gas or steam. Then it is converted into 4 ~ 20mA DC signal output. The applicable media are as follows:

  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 occurrence of leakage of the pressure guiding pipe and pollute the surrounding environment. It can be avoided when using the isolation liquid. Because of the unstable measurement signal.
  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 does the transmitter contact with the media meet hygienic standards, but it should be easy to rinse to prevent cross-contamination of different batches of media.

Extended reading: SI-703 Flush Diaphragm Pressure Sensor

Precautions for use:

In the use process, we should pay attention to consider the following situations:

  1. When measuring the liquid pressure, the installation location of the remote pressure transmitter should avoid the impact of the liquid (that is, the water hammer phenomenon). In order to prevent the sensor from being damaged by overpressure.
  2. When the remote pressure transmitter transmitter freezes in winter. The transmitter installed outdoors must take anti-freezing measures. Avoid expansion of liquid in the pressure port due to icing volume. Lead to sensor damage.
  3. When wiring, pass the cable through the waterproof connector (accessory) or the flexible tube and tighten the sealing nut. In order to prevent rainwater etc. from leaking into the transmitter housing through the cable.
  4. When the remote pressure transmitter is used to measure the liquid pressure. The pressure tap should be opened on the side of the process pipe. In order to avoid sedimentation and accumulation of slag.
  5. To prevent the flange liquid transmitter from contacting with corrosive or overheated media. It is also necessary to prevent scum from depositing in the duct;
  6. When measuring the pressure of the gas, the pressure port should be opened at the top of the process pipeline. And the flange level transmitter should also be installed in the upper part of the process pipeline. In order to quickly deposit the deposited liquid into the process pipeline.
  7. The remote pressure transmitter should pay attention to that the pressure guiding tube of the sensor should be installed in a place with small temperature fluctuation.
  8. When measuring the steam or other high temperature medium of the remote pressure transmitter, it is necessary to connect a condenser such as a buffer tube (coil tube). The operating temperature of the transmitter should not be exceeded.

Extended reading: Smart Differential Pressure Transmitter

Remote Seal Differential Pressure Transmitters Working Principle

What is a diaphragm seal?

Diaphragm seals, also known as chemical seals or remote seals, are used for pressure measurements when the process medium should not come into contact with the pressurised parts of the measuring 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.

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 (< 600 mbar). 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.

Diaphragm type level transmitter working principle

Smart differential pressure transmitters are often used to measure liquid level, flow rate, etc. Differential pressure transmitter cooperates with sealing diaphragm, capillary, etc.

The differential pressure type liquid level gauge uses the principle that when the liquid level in the container changes, the static pressure generated by the liquid column also changes accordingly, as shown in the figure.

For closed tanks. Set the bottom pressure to P. If the pressure on the liquid surface is P3 and the liquid level height is H, then:
P = P3 + Hpg (3-11)
In the formula: p is the medium density; g is the acceleration of gravity.
From the formula ((3-1 “available:
△ P = P-P3 = Hpg (3-12)
Usually the density of the measured medium is known, the pressure difference △ P is proportional to the liquid level height H. The pressure difference on the side will know the measured liquid level height.

When the container under test is open, the gas pressure is atmospheric pressure. The negative pressure chamber of the differential pressure gauge can be vented to the atmosphere. It is known that the pressure gauge can also be used to measure the liquid level at this time.

If the container is closed, you need to connect the negative pressure chamber of the differential pressure gauge to the gas phase of the container.

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.

More

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.

More

In the case of open tanks or underground water wells, Hydrostatic pressure level transmitters are also suitable.

SI-151 Hydrostatic Level Sensor
SMT3151TR Hydrostatic level transmitter-Rod Type
SI-PCM260 Deep Well Water Level Sensor

FAQ

What is remote seal pressure transmitter?

Remote Diaphragm seal pressure transmitter with capillary is used as a level transmitter. Diaphragm Seals also called chemical seals, are used in applications where pressure sensor requires isolation from the process media. These applications are corrosive, high temperature, clogged. Or must sanitary fluids to remain in the pipeline or container. The pressure of the liquid in the process does not affect the pressure sensor. Instead, it is applied to the remote seal. And through the capillary, hydraulic pressure is transmitted to the pressure sensor. Installing and filling the diaphragm seal, the impact on instrument performance will be minimized. More

What is remote seal for level transmitter?

Remote seals are commonly used to protect pressure-measuring instruments including pressure gauges, pressure transmitters, and switches from hot, viscous, contaminated, or corrosive media. As a result, they’re often used in refining, petrochemical, and chemical plants. More Remote Diaphragm Seal System Pressure Transmitters

What is differential pressure transmitter working principle?

The basic principle of a differential pressure transmitter is to divide a space into two chambers with sensitive elements. When introducing pressure into the two chambers respectively. 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.
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. 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.
Extended Reading: Liquid pressure sensor

What is diaphragm seal pressure transmitter?

Diaphragm seal pressure transmitter with flange direct mount is good for level measurement. Diaphragm seals, also known as chemical seals or flush seals. Diaphragm seals work with pressure transmitter, pressure gauges. To prevent 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 manufold. Like remote seal pressure transmitter, DP level transmitter. More

Extended Diaphragm Seal DP Level Transmitter
Extended Diaphragm Seal DP Transmitter is a level transmitter direct mounted on pipe or tank. The isolation diaphragm is in direct contact with the liquid medium.
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.
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.
Remote Diaphragm Seal Pressure Transmitter
Remote seal pressure transmitter, with capillary and diaphragm seal, remote mount. Diaphragm seal systems protect pressure transmitters from hot, viscous, contaminated or corrosive media.



Extended Reading: Differential Pressure (DP) Flow Meters Technology

Sino-Instrument offers Remote Seal Differential Pressure Transmitters. A wide variety of Remote Seal Differential Pressure Transmitter options are available to you. Such as free samples, paid samples. Sino-Instrument is a globally recognized manufacturer of Pressure sensors, located in China. Sino-Instrument sells through a mature distribution network that reaches all 30 countries worldwide. Remote Seal Differential Pressure Transmitter products are most popular in Europe, Southeast Asia, and Mid East. You can ensure product safety by selecting from certified suppliers. With ISO9001, ISO14001 certification.

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Extended Diaphragm Seal DP Level Transmitter

Extended Diaphragm Seal DP Transmitter is a level transmitter direct mounted on pipe or tank. The isolation diaphragm is in direct contact with the liquid medium.

Extended Diaphragm Seal DP Level Transmitter is a field level transmitter that is directly mounted on a pipe or container. The isolation diaphragm is in direct contact with the liquid medium. There is no need to lead out the positive pressure side with a pressure pipe. Therefore, it can measure the liquid level, pressure and density of high temperature, high viscosity, easy crystallization, easy precipitation and strong corrosion. Convert to 4 ~ 20mA. DC signal output.

The flanges are made of high-quality stainless steel materials such as 304 and 316. Wetted diaphragms are made of imported high-quality anti-corrosive materials such as 316L, Hastelloy C-276, Monel, and tantalum.

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.

Features of Extended Diaphragm Seal Differential Pressure Transmitter

  • Simple structure: There are no movable or elastic elements. Therefore, the reliability is extremely high. The amount of maintenance is very small.
  • Easy installation: The built-in structure especially shows this feature. No special tools are required.
  • Convenient adjustment: The two potentiometers of zero position and range can carry out zero point migration or range change at will within the effective range of liquid level detection. The two adjustments do not affect each other.
  • Widely used: Suitable for liquid level measurement of high temperature and high pressure, strong corrosion and other media.

Specifications of Extended Diaphragm Seal Level Transmitter

Measuring range:can be customized within the range of -4-4MPa (-10-10KPa, 0-50KPa, etc.)
Output signal: 4 ~ 20MA.DC two-wire system (analog). Two-wire system 4 ~ 20mA DC signal is superimposed with digital signal. Linear or square root output is selected by the user. (Smart)
Power supply:12 ~ 45V.DC
Range ratio: 10: 1 or 100 to 1
Power supply impact: <0.005% output range / V
Load effect: When the power supply is stable, there is no load effect.
Measurement accuracy: 0.1% of the calibration range. Standard accuracy is 0.2%. If other accuracy is selected, please indicate when ordering and selecting.
Resistance: usually adjustable between 0.1 to 16 seconds. When filling with inert liquid or with a remote transmission device, the time constant will increase.
Startup time: <2 seconds, no warm-up required
Working environment: ambient temperature -29 ~ 93 ℃ (analog amplifier)
 -29 ~ 75 ℃ (digital / smart amplifier)
    -29 ~ 65 ℃ (with display head)
Environmental humidity: 0 ~ 95%
Protection characteristics: protection ability IP65
Explosion-proof type: Flameproof Exd II BT4-6. Intrinsically safe Exia II CT5
Static pressure effect:Zero point error (can be eliminated under static pressure)
Static pressure from 0 ~ 13.7MPa, ± 0.2% / 6.9MPa
 Static pressure exceeds 13.7MPa, ± 0.5% / 6.9MPa

Extended reading: Smart Differential Pressure Transmitter

Applications of Extended Diaphragm Seal DP Level Transmitter

Extended Diaphragm Seal DP Transmitter can measure the liquid level, pressure and density of high temperature, high viscosity, easy crystallization, easy precipitation and strong corrosion and other media. Then convert it to 4-20mA. DC signal output

Mainly used for measurement in the following occasions:

  • Viscous medium at high temperature.
  • Easily crystallized medium.
  • Precipitated media with solid particles or suspended matter.
  • Strongly corrosive or highly toxic media.
  • It can eliminate the leakage of the pressure guiding pipe and pollute the surrounding environment. When the isolation liquid is used, the tedious work of frequently replenishing the isolation liquid due to the unstable measurement signal can be avoided.
  • Continuously and accurately measure the interface and density.
  • 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.
  • Hygiene and cleaning requirements are high.
  • For example, in the production of food, beverage and pharmaceutical industries, not only the location of the transmitter in contact with the media must meet hygienic standards, but it should be easy to rinse.

You may like: Diaphragm pressure gauge

Extended Diaphragm Deal Application

Diaphragm seals are used for the protection of pressure measuring instruments in applications with difficult media. In diaphragm seal systems, the diaphragm of the diaphragm seal affects the separation of the instrument and the medium.

The pressure is transmitted to the measuring instrument via the system fill fluid which is inside the diaphragm seal system.

For the implementation of demanding customer applications, there are a wide variety of designs, materials and system fill fluids available.

Applications

  • Aggressive, highly viscous, crystallising or hot media
  • Process industry
  • Thick-walled or insulated pipelines and vessels

Read more What is a diaphragm seal?

1199EFW Extended Diaphragm Seal

The specifications of commonly used Extended Diaphragm Seals are as follows:

DN50 (2 ”) flange size specification table

FlangeACFEBNumber of bolts nBolt diameter
150LB150120954819418
300LB165127954820818
600LB165127954832818
900LB215165954845826
PN1.6/1.0165125954818418
PN2.5/4.0165125954820418
PN6.4180135954826422

DN80 (3 ”) flange size specification table

FlangeACFEBNumber of bolts nBolt diameter
150LB1901521247420418
300LB2101681247425822
600LB2101681247438822
900LB2401911247454826
PN1.6/1.02001601247420818
PN2.5/4.02001601247424818
PN6.42151701247428822

DN100 (4 ”) flange size specification table

FlangeACFEBNumber of bolts nBolt diameter
150LB2301901558924418
300LB2552001558932822
600LB2752151558945826
900LB2902351558950833
PN1.6/1.02001801558920818
PN2.5/4.02001901558924822
PN6.42152001558928826

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.

Extended reading: SI-703 Flush Diaphragm Pressure Sensor

Diaphragm type level transmitter working principle

Smart differential pressure transmitters are often used to measure liquid level, flow rate, etc. Differential pressure transmitter cooperates with sealing diaphragm, capillary, etc.

The differential pressure type liquid level gauge uses the principle that when the liquid level in the container changes, the static pressure generated by the liquid column also changes accordingly, as shown in the figure.

For closed tanks. Set the bottom pressure to P. If the pressure on the liquid surface is P3 and the liquid level height is H, then:

P = P3 + Hpg (3-11)

In the formula: p is the medium density; g is the acceleration of gravity.
From the formula ((3-1 “available:
△ P = P-P3 = Hpg (3-12)

Usually the density of the measured medium is known, the pressure difference △ P is proportional to the liquid level height H. The pressure difference on the side will know the measured liquid level height.

When the container under test is open, the gas pressure is atmospheric pressure. The negative pressure chamber of the differential pressure gauge can be vented to the atmosphere. It is known that the pressure gauge can also be used to measure the liquid level at this time. If the container is closed, you need to connect the negative pressure chamber of the differential pressure gauge to the gas phase of the container.

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.

More

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.

More

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.

Comparative analysis – 7 Tank Level Measurement Sensors

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

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SI-801 Piezoresistive Differential Pressure Transmitter

Piezoresistive Differential Pressure Transmitter utilizes the piezoresistive effect of semiconductor silicon materials. Realize accurate measurement of differential pressure.

Piezoresistive Differential Pressure Transmitter uses integrated all-welded differential pressure measuring elements. Silicone oil is filled between the chip and the two corrugated diaphragms. This product utilizes the piezoresistive effect of semiconductor silicon materials. To achieve the conversion of differential pressure and electrical signals. The signal output from the Wheatstone bridge on the sensitive chip has a good linear relationship with the differential pressure. Therefore, accurate measurement of the measured differential pressure can be achieved. It is suitable for differential pressure measurement of various gases and liquids in petroleum, chemical.

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

Features of Piezoresistive Differential Pressure Transmitter

  • All stainless steel structure design;
  • Small size, light weight and easy installation;
  • Welded structure, fully sealed;
  • Enclosure protection grade IP65;
  • The sensor is a diffused silicon piezoresistive differential pressure sensor, stainless steel 316L isolation diaphragm;
  • After temperature compensation and aging screening, the performance is stable and reliable;
  • Connector type products can adjust the zero point and fullness externally;

Specifications of Piezoresistive Differential Pressure Transmitter

Range: 0 ~ 10KPa ~ 35MPa
Withstand voltage: three times the range value
Comprehensive accuracy: 0.2% FS, 0.5% FS
Input and output signals: 4-20mA (two-wire system), 0-5 / 1-5 / 0-10VDC (three-wire system)
Supply voltage: 24VDC (10-30VDC)
Medium temperature:-20 ~ 65 ℃
Ambient temperature:-20 ~ 65 ℃
Load resistance: Current output type: maximum 800Ω; voltage output type: greater than 50KΩ
Insulation resistance: Greater than 2000MΩ (100VDC)
Sealing grade: IP65
Long-term stability:0.1% FS / year
Vibration effect: Within the mechanical vibration frequency 20Hz ~ 1000Hz, the output change is less than 0.1% FS
Electrical interface: Hessman connector ( Support customization)
Mechanical connection (thread interface): M20 × 1.5, G1 / 2

Dimensions

Applications

  • Flow measurement
  • Wastewater treatment
  • Wind Diff Pressure undermine
  • Water Diff Pressure at hydropower station
  • urban flood control and waterlogging prevention
  • Underwater engineering
  • Groundwater monitoring
  • Central air-conditioning terminal control
  • Watersaving Irrigation

Working Principle of Piezoresistive Differential Pressure Transmitter

The sensitive element of the piezoresistive differential pressure transmitter is a solid piezoresistive sensitive chip. Silicone oil is filled between the chip and the two corrugated diaphragms.

The measured differential pressure acts on the corrugated diaphragms at both ends. The differential pressure is transmitted to the sensitive chip through silicone oil. The sensitive chip is connected to the special amplifier circuit through the wire. It utilizes the piezoresistive effect of semiconductor silicon materials.

To achieve the conversion of differential pressure and electrical signals. The signal output from the Wheatstone bridge on the sensitive chip has a good linear relationship with the differential pressure.

Therefore, accurate measurement of the measured differential pressure can be achieved. It is used to measure the pressure difference of various gases and liquids. It is suitable for the measurement of differential pressure and water level difference of pipelines in petroleum and chemical industries.

Read more: Differential Pressure Transmitter Installation Guide

The Piezoresistive Effect

The so-called piezoresistive effect refers to the phenomenon that when the semiconductor is subjected to stress, the energy band changes due to the stress, the energy of the energy valley moves, and its resistivity changes.

It was discovered by C.S Smith in the 1954 test of the resistivity and stress change characteristics of silicon and germanium. Semiconductor piezoresistive sensors have been widely used in aviation, chemical, marine, power and medical sectors.

More about Piezoresistive effect From Wikipedia.

Strain pressure sensor VS piezoresistive pressure sensor

In principle, strain-type pressure sensors are caused by changes in the geometry (length or width) of the strained material caused by external pressure (or tension). This in turn causes the resistance of the material to change. The magnitude of the external force can be measured by detecting this resistance change.

Piezoresistive pressure sensors are usually semiconductor pressure sensitive materials. After the semiconductor piezoresistive sensor is subjected to external forces, its own geometry hardly changes. Instead, its lattice parameters change, affecting the width of the forbidden band. Even a very small change in the width of the forbidden band will cause a large change in carrier density. This eventually causes the resistivity of the material to change.

It can be seen that although both materials exhibit changes in resistance to changes in external force, the principles are different. In addition, the sensitivity of strain-type materials to external forces is much lower than that of semiconductor piezoresistive materials.

The sensitivity of the latter is about 100 times that of the former. The characteristics of strained materials are less affected by temperature. Semiconductor piezoresistive materials are sensitive to temperature.

Piezoresistive pressure sensor advantages and disadvantages

Advantages of piezoresistive pressure sensor:

  1. High frequency response, f0 can reach 1.5M;
  2. Small size and low power consumption;
  3. High sensitivity, good accuracy, can measure to 0.1% accuracy;
  4. No moving parts (the sensitive element is integrated with the conversion element).

Disadvantages of piezoresistive pressure sensor:

  1. Poor temperature characteristics;
  2. The process is complicated.

Techincal Support

Capacitive mems pressure sensor

A MEMS pressure sensor is a thin-film element. It deforms when subjected to pressure, and it can be measured using a strain gauge (piezoresistive sensing). It can also be measured by capacitively sensing the change in the distance between the two surfaces.

Capacitive pressure sensor is a pressure sensor that uses a capacitive sensing element to convert the measured pressure into an electrical output with a certain relationship. The characteristics are: low input energy, high dynamic response, small natural effect, good environmental adaptability.

Capacitive differential pressure sensor

Capacitive differential pressure sensor is filled with silicone oil in the left and right chambers of the measuring diaphragm. When the left and right isolation diaphragms are subjected to high pressure pH and low pressure pL respectively, the incompressibility and fluidity of the silicone oil can transmit the differential pressure Δp = pH-pL Measure the left and right sides of the diaphragm.

Because the measuring diaphragm is pre-tensioned before welding, it is very flat when the differential pressure Δp = 0. It makes the capacitances of the two capacitors on the left and right sides of the fixed plate are completely equal. That is, CH = CL. When there is a differential pressure effect, the measuring diaphragm deforms. That is, the moving electrode plate approaches the low voltage electrode plate. At the same time, it moves away from the high voltage measuring electrode plate. This makes the capacitance CH = CL.

More Featured Piezoresistive Pressure Sensor

What is a piezoresistive pressure sensor?

Piezoresistance pressure sensor (piezoresistance type transducer) is a kind of pressure sensor. Piezoresistive pressure sensors, also known as diffused silicon pressure sensors, refer to sensors made using the piezoresistive effect of single crystal silicon materials and integrated circuit technology. The single crystal silicon material is subjected to force. The resistivity changes. The electrical signal output proportional to the force change can be obtained through the measuring circuit. Piezoresistive sensors are used for the measurement and control of pressure, tension, pressure difference, and other physical quantities that can be transformed into changes in force. Such as liquid level, acceleration, weight, strain, flow rate, vacuum degree.

How does a piezoresistive pressure sensor work?

Working principle of piezoresistive pressure sensor:
It is the resistance change when the varistor is pressed. It is amplified by the amplifier and calibrated with standard pressure. The pressure can be detected. The performance of the piezoresistive pressure sensor mainly depends on the varistor (ie varistor), the amplifier circuit, and the calibration and aging process in production.

What do piezoresistive sensors measure?

Using the semiconductor piezoresistive effect, various types of piezoresistive sensors can be designed. The piezoresistive sensor has a small volume, a relatively simple structure, and high sensitivity. It can measure micro-pressures of more than ten micropascals, with good dynamic response. Good long-term stability, low hysteresis and creep. High frequency response, easy production, and low cost. Therefore, piezoresistive sensors have been widely used in measuring pressure, differential pressure, liquid level, acceleration and flow.

How do you test a pressure sensor?

There are 3 commonly used detection methods for pressure sensors. Hope it can help you.
1. Pressure test. The method of detection is to power the sensor. Use your mouth to blow the air hole of the pressure sensor. Use the voltage file of a multimeter to detect the voltage change at the output of the sensor. If the relative sensitivity of the pressure sensor is large, this amount of change will be significant. If there is no change at all, you need to use a pneumatic source to apply pressure.
Through the above method, you can basically detect the condition of a sensor. If accurate testing is required, a standard pressure source is required. Give pressure to the sensor, and calibrate the sensor according to the pressure and the change of the output signal. And when conditions permit, the temperature detection of relevant parameters.
2. Zero point detection. Use the voltage range of the multimeter to detect the zero output of the sensor under no pressure. This output is generally a voltage of mV level. If it exceeds the technical specifications of the sensor, it means that the zero deviation of the sensor is out of range.
3. Detection of bridges. It mainly detects whether the circuit of the sensor is correct. It is generally a Wheatstone full-bridge circuit. Use the ohm file of the multimeter. Measure the impedance between the input terminals and the impedance between the output terminals. These two impedances are the input and output impedances of the pressure sensor. If the impedance is infinite, the bridge is disconnected. It means there is a problem with the sensor or the definition of the pin is not correct.

Sino-Instrument offers over 10 Piezoresistive Differential Pressure Transmitters. A wide variety of  Piezoresistive Differential Pressure Transmitter options are available to you. Such as free samples, paid samples. Sino-Instrument is a globally recognized manufacturer of Pressure sensors, located in China. Sino-Instrument sells through a mature distribution network that reaches all 30 countries worldwide. Piezoresistive Differential Pressure Transmitter products are most popular in Europe, Southeast Asia, and Mid East. You can ensure product safety by selecting from certified suppliers. With ISO9001, ISO14001 certification.

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SI-2000 Differential Pressure Gauge

Differential Pressure Gauge measures the pressure difference between two points. Quickly measure the positive, negative or DP of air or non-corrosive gas.

Differential pressure gauge measures the pressure difference between two independent pressure sources. Differential pressure gauge is a more economical method. Used for process monitoring or control, which allows a small amount of migration of process media. Suitable for air and non-flammable, non-corrosive applications. And certain air and natural gas applications. Using a simple, frictionless magnet spiral movement, it can quickly indicate the pressure of low pressure or non-corrosive gas. Whether positive, negative (vacuum is also available) or differential pressure. This design can prevent vibration, jitter, and overvoltage. No liquid needs to be filled in the watch.

Sino-Inst is a manufacturer of Differential Pressure Gauge. Sino-Inst supplies Differential Pressure Gauges made in China. DWYER 2000 Differential Pressure Gauges, Magnehelic differential pressure gauges are also available.

Features of Differential Pressure Gauge

  • Up to 81 kinds of range selection, can accurately meet your requirements
  • Using simple and unique patented double helix frictionless magnetic moving parts, you can quickly measure the positive pressure of air or non-corrosive gas, measure negative or differential pressure
  • Designed to resist shock, shock and overload protection
  • No liquid U-tube pressure gauge liquid evaporation, freezing, poisoning and leakage problems
  • Can measure fan, blower, filter resistance, furnace ventilation, orifice plate
  • Pressure drop and other system pressures. Can also be used in various purification rooms, biological safety
  • Cabinet, clean bench, dust removal equipment, medical breathing equipment, air intake
  • Sample differential pressure detection
  • Up to 63 models with different ranges and engineering units, suitable for various applications
  • Ultra-thin design: embedded thickness is only 38.5mm, overall thickness is only 52.2mm
  • Patented wave stripe decorative mask, beautiful and elegant
  • Standard accuracy up to 2%; after high precision calibration, up to 1% FS
  • Optional mirror dial to eliminate visual reading error and brushed 304 SS or plated bezel

Specifications of Differential Pressure Gauge

  • Accuracy: ±2% (ascending pressure)
  • Pressure Ranges: 0-5 thru 0-150 psi
  • Dial size: 2″, 2 1/2″, 3 1/2″, 4″, 4 1/2″ and 6″
  • Case: stainless steel
  • Body: aluminum, brass or stainless steel 
  • Wetted Material: body material, Teflon ®, ceramic and various O-ring materials
  • Medium: air and non-flammable, compatible gas (optional natural gas)
  • Shell: cast aluminum or ABS shell, plexiglass beveled panel. Dark gray coating for 168 hours salt spray test
  • Withstand voltage range: -20Hg. to 15 psi (-0.677 bar to 1.034 bar)
  • Temperature range: 20 to 140 °F (-6.67 to 60 °C)
  • Opening size: 114mm
  • Installation positioning: diaphragm for the vertical direction
  • Connector: the same 1/8″ NPT high and low-pressure connector, one pair on the side and one pair on the back
  • Weight: 500g / only
  • Standard accessories:
    • two 1/8″ NPT threaded joints for high and low-pressure joints and connected to rubber hoses;
    • two 1/8″ NPT plugs for blocking the remaining two high and low-pressure ports;
    • Three threaded countersunk mounting connectors (mounting ring, snap ring retainer are used to replace the three ports on the MP and HP metering accessories).
RANGES FOR REFERENCEPaKpaInches of WaterMM of Water Dual Scale    
0-300-0.50-.250-6 in w.ccPa or Kpa
0-600-10-.500-100-.250-62 Pa
0-1000-1.50-1.00-150-0.50-125 Pa
0-1250-20-2.00-250-1.00-250 Pa
0-3000-50-8.00-300-2.00-500 Pa
0-5000-80-10 0-500-3.00-750Pa
-30-0-300-100-200-800-4.00-1.0kPa
-60-0-600-200-500-1000-5.00-1.25kPa
-100-0-1000-300-1000-1250-6.00-1.5kPa
-250-0-2500-500-1800-2000-8.00-2.0kPa
-500-0-5000-600-2500-3000-0.50-2.5kPa
VARIOUS RANGES  CAN BE CUSTOMIZED FOR YOU

You may like: Diaphragm Seal Pressure/ Differential Pressure Transmitters

What is a differential pressure gauge?

SI-D2000 Differential Pressure Gauge

Differential pressure gauges are suitable for measuring small pressure differences between two pressure sources in an industrial process. Measure the pressure loss of the filter and observe the working state of the valve. It is widely used to measure the pressure of fan and blower, filter resistance, wind speed, furnace pressure, orifice differential pressure, bubble water level, liquid amplifier or hydraulic system pressure, etc. It is also used for air-gas ratio control and automatic valve control during the combustion process.

Differential pressure gauge is suitable for measuring the differential pressure, flow rate and other parameters of various liquid (gas) media in the process flow of industrial sectors such as chemical, chemical, metallurgy, electric power, and nuclear power. The instrument structure is all made of stainless steel. Among them, the measurement system (double bellows emergency connection parts) and the pressure guiding system (including joints, conduits, etc.) adopt special structure design and advanced technology.

Principle of differential pressure gauge

How does a differential pressure gauge work ?

Based on the pressure-sensitive element, two bellows with the same stiffness are used. Therefore, they are forced to produce the same concentrated force on the movable bracket under the same measured medium. Because the two sides of the spring sheet do not produce deflection under the action of equal moments. It is still in the original position. In this way, the gear transmission mechanism does not operate. The pointer is still at the zero position.

When different pressures are applied (generally the high-pressure end is higher than the low-pressure end), the forces of the two bellows acting on the movable bracket are not equal. The corresponding displacements are generated. The gear transmission mechanism is driven and amplified. The pointer deflection The latter indicates the differential pressure between the two.

Home > DP Transmitters > D2000 Differential Pressure Gauge

Differential Pressure Gauge Application

The SI-2000 differential gauge is ideal Where safe and reliable pressure measurement is essential:

  • Filtration Monitoring
  • Pressure Drop across a Strainer
  • Flow Rate

Dwyer Magnehelic series 2000 differential pressure gauge

American Dwyer differential pressure gauge/ Dwyer 2000 differential pressure gauge

The Dwyer 2000 series differential pressure gauge is an ultra-low-range, inexpensive, and solid structure field indicator. It uses the frictionless Magnehelic movement principle to eliminate wear, hysteresis and gaps. Without liquid filling, it will not vaporize and freeze. It can quickly indicate the low pressure and non-corrosive gas (positive pressure, negative (vacuum) and differential pressure). There are 81 ranges, the minimum range is 0-60Pa, or 0-6mm water column or 0-0.25′ water column). This design has anti-vibration, shaking and high resistance to overpressure.

Main technical indicators of American Dwyer differential pressure gauge Dwyer 2000

  • Accuracy: accuracy 2% FS (suffix 0 is 3%; suffix 00 is 4%) Rated pressure: -0.7 ~ 1Kg / cm
  • Connection: 1/8 “NPT internal thread, two pairs of high and low pressure ports, on the side and back
  • Overpressure: The vent will open automatically when it is about 1.75Kg / cm2
  • Ambient temperature: -5 ℃ ~ 60 ℃, weight 0.5Kg
  • Outer shell: cast aluminum outer shell, the main body and components pass the 168-hour salt spray test, and the exterior is dark gray coating.
  • Standard accessories: two 1/8 “NPT threaded joints, used as high and low pressure joints and can be connected with rubber tubes; two 1/8” NPT plugs; three threaded countersunk fittings.
  • According to the requirements of the National GMP Drug Production Verification Guidelines for clean workshops, we recommend selecting:
    • Add positive micro-pressure (5-10Pa) to the workshop or room, and select a 2000-60Pa micro differential pressure gauge.
    • Check the filtering effect of coarse, medium and high-efficiency air filters, use differential pressure gauges such as 2000-125, 250Pa, 500Pa or 1Kpa, and observe the pressure difference of the filter at any time to replace the filter.

Scope and model:
2000-60PA 0-60Pa,
2300-120PA, 0- ± 60Pa,
2000-125PA0, -125Pa,
2300-250PA, 0– ± 125Pa,
2000-125PA, 0-250Pa,
2300-500PA, 0- ± 250Pa,
2000-500PA, 0-500Pa,
2000-750PA, 0-750Pa

81 range specifications including 2000-30KPA.
Sino-Inst provides DWYER differential pressure gauge, micro differential pressure gauge, mechanical differential pressure gauge including MAGNEHELIC 2000 series. All products can be ordered, domestic brands include: MACROHELIC and MAGRFHELIC, price concessions, spot supply.

Differential pressure gauge price

Reference Price:
Dwyer 2000 series differential pressure gauge: USD 75.00 / pc
SI-2000 Differential Pressure Gauge: USD49.50 / pc

The exact price needs to be determined according to the product parameters and the quantity purchased.

Differential pressure gauge installation

1-Surface Mount

(1) Installation method one, as shown in the following picture 1. Drill three installation vias with an angle of 120 degrees and a diameter of 4.5mm on the installation plane. Use the corresponding short installation screws in the accessory package to match the screw holes on the bottom of the instrument. Make it secure .
  (2) Mounting method two, as shown in the following figure 2. Take three mounting brackets first. Use the corresponding installation short screws in the accessory package. Fix the mounting bracket to the three mounting screw holes on the bottom of the instrument. Then take the longest three screws. Lock with the installation plane

2-Embedded (panel) installation

Cut the installation and insertion holes with a diameter of 115.5mm on the panel. Insert the meter into the holes. See Figure 3 below. Take three mounting brackets, and use the corresponding installation short screws in the accessory package. Fix the mounting bracket to the three mounting screw holes on the bottom of the meter. Then take the longest three screws. Fasten the meter to the panel.

3-Embedded (color steel plate) installation

Cut the embedded hole with a diameter of 115.5mm on one side of the color steel plate. As shown in figure 4 below, install the A-S1 / S2 panel into the color steel plate.
The pressure port on the back of the meter is firmly installed. Among them, accessories A-S1 / S2 and A-S81 need to be purchased separately.

4-For other installation methods. see the following figure 5. Use special screws A-S9 to fix the installation with the pressure interface on the back of the instrument. Accessories A-S9 need to be purchased separately.

5-Zero adjustment

After installing the instrument, adjust the zero position. Using a suitable flat-blade screwdriver, turn the zero adjustment screw at the bottom of the transparent mask counterclockwise. Align the pointer with the zero position of the dial. During zero adjustment, both the high-pressure port and the low-pressure port can communicate with the atmospheric pressure.

6-Pressure connection

With the standard configuration accessories, according to actual needs, correctly connect the “+” and “-” pressure ports. Note that the instrument has a pair of pressure ports on the side and back. The unused pair of plug seals in the application accessories.

Differential-pressure-gauge-installation-picture-1
Differential-pressure-gauge-installation-picture-2
Differential-pressure-gauge-installation-picture-3
Differential-pressure-gauge-installation-picture-5
Differential-pressure-gauge-installation-picture-4

FAQ

How do you hook up a differential pressure gauge?

Two pressure ports for L (low pressure) and H (high pressure). Different connections can quickly indicate gas pressure. Including positive, negative or differential pressure. Zero calibration can be directly operated externally.
Pressure measurement: Connect the pressure source to any one of the two high-pressure ports with an air pipe, and block the unused one; make one or two low-pressure ports open to the atmosphere.
Differential pressure measurement: Connect the high-pressure source to any one of the two high-pressure ports with an air pipe, and connect the low-pressure source to any one of the two low-pressure ports with an air pipe; block the two pressure ports that are not used on the meter.
Negative pressure measurement: Connect the pressure source to any one of the two low-pressure ports with an air duct, and block the unused one; make one or two high-pressure ports open to the atmosphere.

How to calibrate differential pressure gauge?

Send to Calibration Institute for calibration. Self-calibration requires equipment and qualifications, otherwise it will not be recognized.
If no report is required, you can calibrate yourself:
First, at least one certified high-precision micro-pressure gauge or pressure gauge is required as a reference standard. Then select 5-7 points in the full range and give a fixed pressure difference at both ends of the differential pressure gauge. If it is a micro differential pressure gauge, you can use a micro pressure pump to give pressure to the high pressure port. If it is a large number of differential pressure gauges, you can use a liquid pump to give pressure to the high-pressure port. Then observe the reading between the reference standard and the differential pressure gauge, record and calculate the relative error.

What is the function of a pressure gauge?

The role of the pressure gauge is used to measure and indicate the size of the pressure in the pressure product. If the pressure product does not have a pressure gauge, or if the pressure gauge fails, the pressure of the pressure product cannot be expressed. This directly threatens safety.
A sensitive and accurate pressure gauge is installed on the pressure product. The operator can operate the pressure product correctly with the pressure gauge to ensure safe and economical operation.
The pressure gauge can accurately indicate the level of the steam pressure in the pressure product. The operator can adjust the heating degree of the product according to the indicated value of the pressure gauge. In order to ensure the requirements of the gas department and the safe operation of pressure products.

Sino-Instrument offers over 50 Differential Pressure Gauge products. About 50% of these are differential pressure meters, 40% are water meters, and 40% are level meters.
A wide variety of Differential Pressure Gauge options are available to you, such as free samples, paid samples.
Sino-Instrument is a globally recognized supplier and manufacturer of Differential Pressure Gauge, located in China.
The top supplying country is China (Mainland), which supply 100% of Differential Pressure Gauge respectively.

Sino-Instrument sells through a mature distribution network that reaches all 50 states and 30 countries worldwide. Differential Pressure Gauge 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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SI3151 Level TRANSMITTERS Direct Mounted Flange Type

Sino-Instrument > level transmitter > Hydrostatic for Liquids

High-performance level measurement using a differential pressure transmitter.

  1. High-reliability micro-capacitance silicon cell
  2. All welded construction with no flange ‘O’ rings
  3. Exceptional resistance to harsh environments
  4. Electronic linearisation to correct tank shape
  5. Hart® 5.2 multi-drop communication
  6. Versatile indicator with 5-digit display
  7. Field repair possible with common spare parts
  8. The built-in loop calibration facility
  9. Wide range of flange types
  10. Large installed base

Most DP type level transmitters use an ‘O’ ring seal,

which will perish within 6 to 12 months usage in a hostile process environment. 

The FCX series transmitter uses an all-welded construction with fill fluid,

that has been subjected to high vacuum for an extended period to remove entrained air. 

This provides long term reliability not found in any level transmitter of its type.

Each application is different. Please feel free to get in touch to discuss your requirements.

Data sheet:

https://www.drurylandetheatre.com/SI/SMT3151TLT Direct-mounted level (pressure) transmitter.pdf

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Flange Mounted Differential Pressure Transmitter

Flange Mounted Differential Pressure Transmitter can be directly installed on the pipe or tank. Based on an ordinary pressure/differential pressure transmitter, a Flush flange or extended flange is added. It can be used for differential pressure measurement and liquid level measurement.

Mainly used to measure high temperature, easy to solidify or crystallize, containing suspended solids, too viscous, corrosive or other media that need to maintain sanitary conditions and cannot be contaminated.

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

Sino-Inst Flange Mounted Differential Pressure Transmitter uses advanced microprocessing technology and digital communication technology. It outputs a 4 to 20 mA DC signal corresponding to the measured differential pressure. It can also be configured with the HART protocol.

SMT3151LT Flange Mounted Differential Pressure Transmitter can replace EJA210E. It is a functional replacement for Rosemount 3051 and Yokogawa EJA.

Extended reading: How to calibrate HART pressure transmitters

Flange Mounted Differential Pressure Transmitter Features:

  • Used to measure the differential pressure of corrosive and non-corrosive gases, steam and liquids;
  • Using a stainless steel diaphragm;
  • Applicable to various hazardous places;
  • Output linear DC current proportional to the differential pressure value;
  • Provide various isolation diaphragms to meet special applications, such as liquid level measurement, corrosive media;
  • High measurement accuracy, 0.1%FS, 0.5%FS;
  • Extensible measurement range;
  • Aluminum and stainless steel housing;
  • With intrinsically safe explosion-proof and isolated explosion-proof capabilities. Can be used in various hazardous places.

Extended reading: Smart Differential Pressure Transmitter

Specification of Flange Mounted Differential Pressure Transmitter

ModelTransmitter type
SMT3151LTFlange liquid level transmitter
CodeScale range
40-4.0~40kPa(0-400~4000mmH2O)
50-20~200kPa(0-2~20mH2O)
60-70~700kPa(0-7~70mH2O)
70-210~2100kPa(0-21~mH2O)
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)
251”DN25
401.5”DN40
502”DN50
803”DN80
04”DN100
CodeProcess connection pressure rating
ANSI American Standard (HG20615)DIN European Standard (HG20592)
A150LBPN16/25
B300LBPN40
C600LBPN64
D900LBPN100
CodeHigh pressure side diaphragm
A316 stainless steel
BHastelloy C
CMonel
DTantalum
ETitanium
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:

Applications

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 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.

More

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.

More

Flange Mounted Differential Pressure Transmitter Working principle

1. Headcover; 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

The Flange Mounted Differential Pressure Transmitter is directly mounted on the reserved flange at the bottom of the pipeline or container. It contacts the liquid through the isolation diaphragm.

When the diaphragm is pressurized, it will produce a slight deformation. The displacement of the diaphragm will move with the change of the differential pressure. This change is accurately converted into a 4-20mA DC two-wire current, voltage or digital HART output signal by the amplifier circuit to achieve pressure measurement and transmission.

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

Single flange. VS. Double flanges 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 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 temperatures, 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, and 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.

More Pressure and Level Measurement Solutions

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

Sino-Inst can offer you with Flange Mounted Differential Pressure Transmitter. Our transmitters can work for you just like EJA210E.

Our Flange Mounted Differential Pressure Transmitters are widely exported to various countries. Including USA, UK, Argentina, Singapore, etc. If you need to purchase Flange Mounted Differential Pressure Transmitter, or have related technical questions, please feel free to contact our sales engineers!

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SMT3151DP Smart Differential Pressure Transmitter

SMT3151DP Smart Differential Pressure Transmitter integrates differential pressure measurement, display, and transmission output. A smart differential pressure transmitter is used to measure the level, density, flow, and pressure of liquid, gas, or steam.

Smart Differential Pressure Transmitter Outputs standard signals (such as 4 ~ 20mA, 0 ~ 5V). It can also be configured with RS485 digital interface standard Modbus RTU protocol output. Or HART protocol.

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

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

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)

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Differential Pressure Transmitter PDF

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: to 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.

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Smart Differential Pressure Transmitter Applications

SMT3151DP smart differential pressure transmitter is suitable for applications like:

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.

Frequently
Asked
Questions

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.

More Featured Pressure Measurement Solutions

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

Sino-Inst 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.

If you need to purchase Smart Differential Pressure Transmitters, or have related technical questions, please feel free to contact our sales engineers!

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DP Level Transmitter-Differential Pressure Tank Level Measurement

DP Level Transmitter uses pressure readings and the specific gravity of the medium to calculate the liquid level. Differential pressure level measurement is a common measurement technology. It can be used for closed-tank and open-tank level measurements.

The DP Level Transmitter measurement system includes differential pressure transmitters, flanges, seal diaphragms, capillaries, wet legs/dry legs, and DP transmitters.

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

Featured DP Level Transmitters

There are 5 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
  5. Wet legs/Dry legs

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 the 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 transmitters

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

The differential pressure level transmitter is an instrument that uses the pressure generated by the liquid column to measure the height of the liquid level. When the liquid level changes, the pressure received by the diaphragm at the high-pressure side flange will change accordingly. The differential pressure value calculated by the transmitter will also change accordingly. There is a linear relationship between them.

Normally, the high-pressure side (H side) and the low-pressure side (L side) cannot be installed reversely. Generally, the H side is installed at the lower part of the equipment, and the L side is installed at the higher part of the equipment. Before installation, the flange surface of the equipment should be cleaned and the gasket should not be placed off-center to prevent the diaphragm from being punctured or deformed, causing distortion of the transmitter.

SMT 3151 Differential Pressure Level Measurement

Differential pressure transmitter level measurement calculation

When using a 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

DP level transmitter calibration

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:

  1. Unscrew the protective cover of the differential pressure liquid level transmitter. It can be adjusted by connecting an 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 potentiometers. Make it output a current of 4mA.
  3. Pressurize the differential pressure liquid level transmitter to full scale (10 meters). Adjust the full-scale resistor. Make it output a current of 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.

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More Pressure and Level Measurement Solutions

Sino-Inst (drurylandetheatre.com) offers over 20 DP transmitters for liquid level, pressure, flow, and density measurement. Differential pressure (DP) level transmitters are suitable for measuring water and other liquid level.

We are a differential pressure level transmitter supplier, located in China. Our products are widely exported to the United States, Australia, Singapore, Indonesia, etc. You can ensure product safety by selecting from our products, including IOS9000, and… certification.

If you need to purchase DP Level Transmitters or have related technical questions, please feel free to contact our sales engineers!

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