In contrast to other pressure sensors, differential pressure sensors occupy a special position. They measure the differential pressure that arises between two pressure levels and thus detect how they relate to each other in a specific pressure range. The pressure difference is reliably measured by the differential pressure sensors, which in turn are based on the piezoresistive and capacitive measuring principle.

Especially when it comes to industrial requirements, differential pressure measurement is ideal for recording the exact flow of liquids and gases. Differential pressure transmitters are also designed for a wide range of applications in pneumatics and hydraulics as well as process engineering. They are used to monitor critical limit values, regulate and control the pressure in machines and systems, regulate temperatures and much more. We have high-quality differential pressure transmitters with our guaranteed quality 100 % "Made in Germany" available for you.

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Sophisticated differential pressure monitoring with SEIKOM

Like more than 10,000 well-known customers already do, you too can place your trust in our sophisticated solutions for professional Measurement and control technology. For many years now, we have stood for quality and reliability with our experience and expertise when it comes to differential pressure sensors, Pressure transmitter and Heating, ventilation, air conditioningdevices, temperature sensors and much more. Our large selection of sophisticated technology impresses not only with innovative construction methods, designs and functionalities, but also with first-class workmanship and high-quality materials. Through continuous further development, we ensure that these are in line with the current state of progress.

In addition, we at SEIKOM Electronic are one of the few companies on the market that can offer you ATEX products and a Safety Integrity Level range. With our Flow monitor SIL2 we meet the high requirements for potentially explosive atmospheres, so that you benefit directly from our specialization.

We attach great importance to sound advice and ongoing support. With a customer-oriented service, it is a matter of course for us to take a lot of time personally to answer your questions. Be it in relation to differential pressure sensors or our many other products. We have also implemented exceptionally fast shipping for you. This means that all orders that we receive by 4 p.m. are dispatched on the same day.

Why choose differential pressure sensors?

Differential pressure sensors measure and monitor the difference in pressure between two areas during the flow of gases, vapors and liquids. They not only detect the pressure difference, but also convert it into an electronic signal so that you can read off an exact measurement result at the end. This feature provides you with significant advantages in many areas, which is why differential pressure transmitters or differential pressure switches are regularly used in industry or in ventilation and air conditioning technology, for example.

The advantages of differential pressure sensors include

  • Wide range of applications
  • Precise pressure measurements between two points
  • Ideal for sensitive measurements with small pressure differences
  • Available in various sizes and configurations for individual requirements.
Differential pressure sensors

How do differential pressure sensors work?

To explain how differential pressure sensors work, it is worth taking a look at their design. Differential pressure sensors have two flexible diaphragms that are located between two airtight chambers and separate them from each other. They are also equipped with process connections. Pressure exerted on the chambers sets the diaphragm in motion towards one side or the other, depending on the pressure difference. The pressures act in opposite directions on the diaphragm. This means that if the pressure in a chamber falls or rises, the diaphragm of the differential pressure sensors moves towards the chamber with the lower pressure. If the pressure remains the same, it remains flat.

As differential pressure sensors detect a direct comparison of two different pressures, it is irrelevant whether the media are the same or different.

steel-pipes-and-cables-in-a-plant (11)

Piezoresistive and capacitive differential pressure sensors

To ensure that you receive a measurement result at the end, the deformation is converted into an electrical output signal representing the pressure difference, depending on the measuring principle used. A distinction is made between piezoresistive differential pressure sensors and capacitive differential pressure sensors.

In the former, the sensor reacts to the deformation of the diaphragm caused by pressure by changing the electrical resistance. Very thin membranes are usually installed in a differential pressure switch or differential pressure transmitter for this purpose. These types of differential pressure sensors are particularly common in medical technology or the aerospace industry. They have very high precision at low pressure ranges and, with their robust long-term stability, are less sensitive to temperature fluctuations. Because they are also very compact, they are suitable for environments that are difficult to access. However, they are somewhat sensitive to vibrations and must be calibrated regularly.

In contrast, a capacitive differential pressure sensor refers to the capacitance between two conductive plates that are separated by the diaphragm as soon as the distance between them changes due to the pressure difference. Heating, ventilation and air conditioning technology benefits from this type of differential pressure sensor when it comes to recording and regulating air pressure, as does industrial process control when it comes to monitoring pressure conditions in pipes and tanks. Their advantage is their particularly high sensitivity, so that measured values can be accurately recorded even in very low pressure ranges. In addition, they are hardly affected by temperature fluctuations and mechanical influences.

Pressure transmitters are always used when you want to keep a continuous eye on the pressure, fill levels or flow rate of machines and systems. They can be used to measure absolute pressure, differential pressure and relative pressure. Absolute pressure refers to zero pressure, which is in a vacuum. Atmospheric pressure is usually around 1 bar (1,000 hPa), although this depends on the individual site conditions. Our pressure transmitters measure between -1 bar and 300 bar. By determining the differential pressure, you obtain the pressure between two absolute pressures. Relative pressure sensors measure the difference between the ambient pressure and the measured pressure.

A pressure transmitter for measuring pressure is equipped with various components such as pressure connections, a sensitive pressure sensor, the pressure connections and the device electronics, to name just a few. The sensors in particular are of great importance, as they record the pressure and convert it into the corresponding output signal. The same importance is attached to the pressure connections, via which the pressure is transmitted to the sensor, and the diaphragms, usually ceramic diaphragms, as pressure-sensitive parts. The housing protects the entire electronics of the pressure transmitter from environmental influences and other stresses.

Both the material and the workmanship as well as the quality of the software are decisive for us during production. So choose a model that meets our high standards. Our products can even be used in specific requirement areas.

This is what you can expect from differential pressure sensors in our range

We offer a large selection of pressure transmitters and pressure switches that meet a wide range of requirements. With the Allrounder PTH-3202 differential pressure transmitter, we provide you with a high-precision measuring device for monitoring and controlling pressure differences in gases. The versatile measuring range, which extends from -50 to 2,500 Pa, should be emphasized. This ensures flexible application in various industrial scenarios, be it very low or very high pressure requirements.

The PTH-3202 differential pressure transmitter provides various options for the analog output to output the measurement data. These include: 0 to 10 V and 4 to 20 mA, which ensures a high level of compatibility with different control and monitoring systems.

With an operating voltage of 24 V AC/DC, the differential pressure transmitter is suitable for most industrial applications and is geared towards efficient operation with its high performance and low power consumption of maximum 0.34 W.

In terms of the accuracy of the output signal, you can be pleased with our differential pressure transmitter, which has a deviation of less than 0.5 % of the measured value plus 0.3 % of the measuring range, plus 2.5 Pa.

On request, the pressure transmitters are available with a display (suffix "-DF") with a switching output (suffix "-DR") and with a practical connection set consisting of a hose extension and connections (suffix "-CK").

As the differential pressure transmitter is specially designed for measuring gases, you can use it in process automation, as an HVAC differential pressure sensor and in many other areas.

If you have any further questions about our differential pressure sensors or would like individual advice, we are always your first point of contact. Please contact us by phone or e-mail without obligation. You are also welcome to take a look at our many other Product categories and discover our professional selection for high quality requirements.

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Overview of the PTH differential pressure transmitters

PTH-3202PTH-3502PTH-3202-DF PTH-3203-DFPTH-3502-DFPTH-3202-DRPTH-6201PTH-6201-DFPTH-6202PTH-6502


Display indication-----
Resolution 0.1 Pa-----
Flow measurement-----
Modbus communication----
Quickplug™ connection--
Connection with screw terminals--------
Cable gland PG11, Ø3-10mm--------
Signal output: 0-10 V, 4-20 mA,
2-10 V, 0-20 mA
Relay output 1 ma - 1 A SPDT 0-30 V-
Available pressure measuring ranges888108CustomizableCarCarCarCar
Available flow measurement ranges141414Customizable14


Pressure measuring range (Pa)-50 ... 500 ... 500-50 ... +500 ... 250 ... 5000 ... 2,5000 ... 2,5000 ... 2,5000 ... 2,5000 ... 5,000
0 ... 1000 ... 1,0000 ... 1000 ... 500 ... 1,000
0 ... 1500 ... 1,6000 ... 1500 ... 1000 ... 1,600
0 ... 3000 ... 2,0000 ... 3000 ... 2000 ... 2,000
0 ... 5000 ... 2,5000 ... 5000 ... 2500 ... 2,500
0 ... 1,0000 ... 3,0000 ... 1,0000 ... 5000 ... 3,000
0 ... 1,6000 ... 4,0000 ... 1,6000 ... 6250 ... 4,000
0 ... 2,5000 ... 5,0000 ... 2,5000 ... 1,0000 ... 5,000
0 ... 1,250
0 ... 2,250
Flow measurement range (l/s - m3/h - m3/s - cfm)0 ... 1.000 ... 1.000 ... 1.000.000 ... 9,9990 ... 1.00
0 ... 3.000 ... 3.000 ... 3.000 ... 3.00
0 ... 5.000 ... 5.000 ... 5.000 ... 5.00
0 ... 10.000 ... 10.000 ... 10.000 ... 10.00
0 ... 30.000 ... 30.000 ... 30.000 ... 30.00
0 ... 50.000 ... 50.000 ... 50.000 ... 50.00
0 ... 99.990 ... 99.990 ... 99.990 ... 99.99
0 ... 100.00 ... 100.00 ... 100.00 ... 100.0
0 ... 300.00 ... 300.00 ... 300.00 ... 300.0
0 ... 500.00 ... 500.00 ... 500.00 ... 500.0
0 ... 1,0000 ... 1,0000 ... 1,0000 ... 1,000
0 ... 3,0000 ... 3,0000 ... 3,0000 ... 3,000
0 ... 5,0000 ... 5,0000 ... 5,0000 ... 5,000
0 ... 9,9990 ... 9,9990 ... 9,9990 ... 9,999
Power supply 24 VAC +- 15%, 50/60 Hz--------
Voltage supply 13.5 - 28 V DC----------
Power consumption0.34 W0.34 W0.5 W0.5 W0.5 W0.5 W0.34 W0.5 W0.34 W0.34 W
Ambient temperature -20 ... 40°C (up to 70°C with DC power supply)----------
Protection class IP55----------
Long-term stability over one year4.0 Pa8.0 Pa4.0 Pa4.0 Pa8.0 Pa4.0 Pa4.0 Pa4.0 Pa4.0 Pa8.0 Pa
Dimensions 77 x 91 x 38 mm----------
Accuracy display/Modbus
< 0.5% x measured value + 2.5 Pa
< 0.5% x measured value + 5 Pa--
Accuracy, analog output signal
< 0.5% x measured value + 0.3% x measuring range + 2.5 Pa
< 0.5% x measured value + 0.3% x measuring range + 5 Pa--

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