SI-804DP Small Differential Pressure Sensor

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SI-804DP Small Differential Pressure Sensor

Small Differential Pressure Sensor SI-804DP is a low-cost diffused silicon differential pressure transmitter. It can measure the differential pressure of water, air and other media. And supports high and low temperature customization (-196℃~600℃). Optional LED, LCD and other local displays.
SI-804DP Small Differential Pressure Sensor has standard voltage, current, and RS485 signals to choose from. It is widely used in differential pressure, liquid level and flow measurement and control in process control, aviation, aerospace, automotive medical equipment, HVAC and other fields.

RFQ Pressure Sensors

Features of Small Differential Pressure Sensor

  • 316L stainless steel isolation diaphragm structure
  • With current line control and reverse polarity protection
  • Integrated and compact structure, easy to install
  • Anti-shock, anti-vibration, anti-electromagnetic interference
  • Convenient to measure differential pressure value
  • Intelligent digital dedicated circuit
  • LED digital tube on-site display, LCD intelligent display optional
  • The appearance and structure are diversified and can be customized according to customer requirements, high and low temperature customization (-196℃~600℃).
Small Differential Pressure Sensor-with display
Small Differential Pressure Sensor-with display 2
Small Differential Pressure Sensor-high temperature-low temperature
Small Differential Pressure Sensor-Female Thread
low cost differential pressure sensor

Technical Parameters

Performance parametersIntegrated differential pressure transmitter
ModelSI-804DP
Power supply12~36V power supply
Output signal4~20mA, 1~5V, 0-20mA, 0~5V, RS485, etc.
Measuring rangeAny range within -0.1~10MPa
Compensation temperature-10-70℃
Storage temperature-40~125°℃
Medium temperature-20~85℃(Customized-196℃~600℃).
Housing protectionIP65
Pressure typeDifferential pressure
Comprehensive accuracyLevel 0.2, 0.3, and 0.5 are optional
Zero temperature drift±0.03%F.S/C
Sensitivity temperature drift±0.03%F.S/C
Overload pressure200%F.S
Long term stability±0.2%F.S/y
Natural frequency5KHz~650KHz
Electrical connectionsDirect Lead/Aero Plug/Hersman (or customized)
Measuring mediumOil, water, gas and other media compatible with 316 stainless steel
Process connectionThreaded connection (size can be customized)
SI-804DP Small Differential Pressure Sensor Dimension

Small Differential Pressure Sensor Working Principle

Before understanding how a differential pressure sensor works, let’s understand a few more basics.

Differential pressure is the pressure difference between two places of process equipment. The pressure at these two places may be gauge pressure or negative pressure when viewed individually. In fact, it is the pressure difference between gauge pressure or negative pressure at two places of process equipment.
For example, P1=900KPa, P2=800KPa, ΔP=P1-P2=100KPa.
For differential pressure, know the pressure at two locations on the process equipment. Through the pressure difference, you can know the actual flow rate of the fluid or the pressure difference or the level of the fluid in the container.

Differential pressure is important in a variety of industries, especially in the fields of fluid dynamics and process control.

Flow measurement: Differential pressure is often used to measure the flow of fluids such as water, gas or steam. A pressure drop can be created by placing a throttling device (such as an orifice plate, venturi, or flow nozzle) at a specific location in the fluid flow path. Differential pressure sensors measure this pressure drop, allowing the flow rate and flow rate of the fluid to be calculated.

Level measurement: The level of a liquid can be measured in a closed or open container by measuring the pressure difference between the top and bottom of the liquid.

Filter Monitoring: In filtration systems, differential pressure is used to monitor the status of the filter. As the filter becomes clogged, the pressure difference across the filter increases. By monitoring this change, you can determine when the filter needs to be replaced or cleaned.

Pressure balance: In some processes, the pressure difference between two areas needs to be monitored and maintained to ensure efficient transfer of material or energy.

HVAC Systems: In HVAC systems, differential pressure is used to monitor the condition of air filters, the efficiency of fans, and the balance of airflow in the system.

how does a differential pressure sensor work

The core part of the diffused silicon differential pressure transmitter is a diffused silicon pressure sensor. This sensor is formed by diffusing doped materials on the silicon wafer to form a piezoresistive effect load measuring element. When pressure is applied to the silicon wafer, the resistance value of the silicon wafer changes.

In a differential pressure transmitter, two pressure ports are connected to the two pressure points to be measured. When the pressure between two points is different, the silicon wafer will undergo slight deformation, causing the resistance value on it to change.

Changes in resistance on the silicon chip are converted into electrical signals. Typically an analog voltage or current signal (e.g. 4-20mA) that is proportional to the pressure change. This signal can be further processed and analyzed.

At the same time, diffused silicon differential pressure transmitters usually include temperature compensation functions. Since temperature changes will affect the accuracy of the sensor, the built-in temperature sensor is used to detect changes in ambient temperature and automatically adjust the output signal to ensure measurement accuracy.

To test the differential pressure sensor, you can simply follow the following steps:

  • Check the appearance: First check the appearance of the differential pressure sensor to make sure there is no obvious damage or corrosion.
  • Connect power: Connect the sensor to an appropriate power source and check to see if any power indicator light comes on.
  • Apply reference pressure: Apply a known differential pressure across the sensor. This can be accomplished by using a calibrator or other pressure source.
  • Reading the output: Measure the sensor’s output signal, usually a current or voltage signal, and check whether this signal is proportional to the applied differential pressure.
  • Accuracy check: Compare the sensor reading with that of a standard pressure gauge to check for errors. If necessary, perform calibration.
  • Response time test: quickly change the input pressure and observe the response time of the sensor output.
  • Stability and repeatability testing: Monitor sensor output over time to check its stability and consistency of repeated measurements under the same conditions.

More about: Pressure Transducer Troubleshooting: Expert Insights & Tips

A venturi is a device that utilizes the principles of fluid dynamics. It causes changes in fluid velocity at specific parts of the pipe, which in turn causes changes in pressure. As the fluid passes through the constricted portion of the venturi, its velocity increases, causing the pressure at that point to decrease. The pressure difference at the two ends of the venturi tube (before and after contraction) can be measured by a differential pressure sensor.

This pressure difference is directly related to the flow rate of fluid flowing through the venturi tube. Therefore, venturi tubes are often used as part of flow measurements, especially when measuring liquid or gas flow in large diameter pipes.

  • Industrial process control: In industrial piping systems, differential pressure sensors are usually installed at flow measurement points (such as venturi tubes, orifice plates, next to flow nozzles), level measurement vessels, or filter systems.
  • HVAC systems: In HVAC systems, differential pressure sensors are often installed near air ducts, filters, and fans to monitor air flow and system balance.
  • Automotive Applications: In automobiles, differential pressure sensors may be installed in the exhaust system (to monitor particulate filter clogging) or in the fuel system (to measure the performance of the fuel pump).
  • Medical Equipment: In some medical respiratory equipment, differential pressure sensors are used to monitor airflow and pressure.

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Differential pressure sensors are widely used in various industries. Their main function is to measure the pressure difference between two points.

In addition to simple differential pressure measurement, it can also be widely used to measure the flow of fluids (such as water, gas, steam) in pipelines. Differential pressure sensors are used to measure the level of liquids in open or closed containers. In heating, ventilation and air conditioning (HVAC) systems, differential pressure sensors are used to monitor the condition of air filters, fan efficiency and air flow. and other applications.

We, Sino-Inst, are a professional manufacturer of differential pressure sensors. Our SI-804DP Small uses a diffused silicon differential pressure oil-filled core as the load measuring element. Supports various parameter customization, including high temperature, low temperature, signal output, etc.

If you need to purchase a differential pressure sensor or have related technical questions, please feel free to contact us!

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    Small Differential Pressure Sensor-Factory Customization | SI-804DP

    Differential Pressure Sensor SI-804DP is a low-cost model, Can measure water, air and other media. Supports high and low temperature customization (-196℃~600℃).

    Product SKU: SI-804DP Small Differential Pressure Sensor

    Product Brand: Sino-Inst

    Product Currency: USD

    Product Price: 150

    Price Valid Until: 2029-09-09

    Product In-Stock: InStock

    Editor's Rating:
    5