Selection and Application of Pressure Sensor

Attention should be paid when choosing:

Due to different structures, pressure sensors can be divided into absolute pressure measurement, relative pressure to the atmosphere and different pressure. Because there is a vacuum reference pressure in the sensor itself, the measured pressure has nothing to do with the atmospheric pressure when measuring the absolute pressure, which is relative to the vacuum pressure. The relative pressure to the atmosphere is based on the atmospheric pressure as the reference pressure, so the elastic membrane side of the sensor is always connected with the atmosphere. The atmospheric pressure is related to the altitude above the ground, the change of water vapor content in the atmosphere in four seasons, and the change of the contents of various gases in different locations and compositions of the atmosphere. Therefore, the measured relative pressure is related to the above factors. In addition, the fluid pressure can be guided from both sides of the elastic membrane of the sensor, which can measure the differential pressure of the fluid at different locations or between the fluids. Pressure sensors with different structures should be selected for different purposes.

Attention should be paid when applying:

The selection of pressure range should mainly consider three factors: the maximum overpressure capability of the sensor, the relationship between accuracy and pressure range, and the relationship between sensor price and pressure range.

Full temperature range accuracy refers to the accuracy that the pressure sensor should achieve in the whole temperature range. It can also be divided into four categories.:0101 - 011 %FS;011 - 1 %FS;1 - 2 %FS;2 - 10 %FS. When the static accuracy reaches 011 - 1% FS, the accuracy of the whole temperature range may be only 1 - 2% FS, or even 2 - 10% FS.

Generally, the output of a common pressure sensor is an analog signal. The full range output voltage can reach 100 - 150 mV at short range and the output current is 0 - 0101 mA. The voltage of the long-range output signal will be attenuated. The current signal output should be used. After amplifying the current by a pressure transmitter, the current signal below 20 mA can be output. Prices will multiply in this way.

The way of operation is also an important issue to be considered. For example, when sensors are used to measure gas pressure, the situation is different from that of liquid pressure.

Generally, the temperature range of pressure sensors is divided into four categories: general commercial grade, ranging from - 10 - 60 C; industrial grade, ranging from - 25 - 80 C; military grade, ranging from - 55 - 125 C; special grade, ranging from - 60 - 350 C.Usually used pressure seals are rubber pad (or O-ring), epoxy resin, PTFE pad, taper hole matching, pipe thread matching, and welding, etc. The sealing material used determines the working temperature range of the pressure sensor.