The selection of industrial pressure sensor should mainly consider its pressure range, pressure medium, accuracy level, temperature range, signal output, excitation voltage, interchangeability, explosion-proof and protection level.
(1) Pressure range: first of all to confirm the maximum value of the measured pressure, generally should choose a pressure range than the maximum value of about 1.5 times the transmitter.
(2) pressure medium: general industrial pressure sensor contact media part of the material used is 316 stainless steel, if your medium on the 316 stainless steel has no corrosive, then basically all the pressure transmitter is suitable for you to the media pressure measurement. If your medium on the 316 stainless steel corrosive, then we have to use chemical sealing, so that not only play can measure the pressure of the medium, but also can effectively prevent the medium and the industrial pressure sensor contact with the liquid part of the contact, so as to play a protection of the pressure transmitter, to extend the life of the pressure transmitter.
(3) Accuracy level: The accuracy is determined by non-linearity, hysteresis, non-repeatability, temperature, zero bias scale, and the effect of temperature. But mainly by the nonlinearity, hysteresis, non-repeatability, the higher the accuracy, the higher the price. So according to the pressure transmitter measurement environment to choose the appropriate level of accuracy does not necessarily have to use a very high precision.
(4) temperature range: an industrial pressure sensor will generally be labeled with two temperature ranges, namely, the normal operating temperature range and the temperature can be compensated for the range. Normal operating temperature range refers to the transmitter in the working condition is not destroyed when the temperature range, in excess of the temperature compensation range, may not reach its application performance indicators.
The temperature compensation range is a typical range that is smaller than the operating temperature range. Operating within this range, the industrial pressure sensor will certainly meet its performance specification. Temperature variation affects the output in two ways: zero drift and full scale output.
(5) signal output: signal output mainly mV, V, mA and frequency output digital output, select the output should be considered in the production process of a variety of factors. (Such as the distance between the transmitter and the system controller or display, the presence of interference signals, large noise and vibration, etc.).
(6) excitation voltage: the type of output signal to determine how to choose the excitation voltage.
(7) Transmitter interchangeability: the selected pressure transmitter should be able to adapt to a number of production processes, which can reduce corporate spending.
(8) explosion-proof and protection level: in special occasions to consider the use of explosion-proof and protection level.
Common faults of Industrial Pressure Sensor
(1) Line failure. When there is a line failure, the computer display value is abnormal, the transmitter junction box will be opened, check whether there is a false connection, short connection or disconnection of the line phenomenon, in the use of power measurement, shake insulation and measurement of resistance and other methods of troubleshooting.
(2) Frequency interference. In the wiring, a variety of signal lines interfere with each other, especially in the power line and the signal line strung in the same pipeline to produce more serious interference, which will lead to the transmitter does not communicate or even lead to errors. Can be avoided by increasing the distance between the instrument cable and power cable groove frame to avoid such errors.
(3) Pilot tube failure. Pilot tube failure usually has a pilot tube blockage, pilot tube leakage, pilot tube accumulation of three types of faults, pilot pressure blockage is generally caused by the discharge of untimely or dirty media, sticky, etc.: pilot tube leakage is caused by the transmitter to connect the power, shut-off valves and other accessories are more, increased leakage points: pilot tube accumulation of liquid is usually due to the gas pressure way unreasonable or the installation of the pilot tube is caused by the wrong pilot tube, the pilot tube accumulation of liquid will affect the measurement accuracy. (4) Electricity
(4) electrical signal transmission failure. industrial pressure sensor if used or maintained improperly will easily lead to electrical signal transmission failure, for example, in order to save time will be placed near the transmitter to be measured equipment, resulting in the signal transmission distance is too far, the signal will be interference or attenuation phenomenon, this time according to the needs of increasing the cross-sectional area of the cable line.
Industrial Pressure Sensor Troubleshooting
- Output Signal Zero
When pressure transmitter appears the phenomenon of zero pressure, you can deal with it from the following aspects: firstly, check whether there is pressure in the pipeline, whether the instrument is normal power supply, and after that, check whether there is the phenomenon of power supply polarity reversal, and finally, check whether there is the phenomenon of electronic Firstly, check whether there is pressure in the pipeline, whether the instrument is normally powered, then check whether there is the phenomenon of reversing the polarity of the power supply, and finally check the electronic circuit board, the pressure-sensitive membrane head, the power supply of the transmitter and so on.
- Pressurized unresponsive
If pressurized unresponsive, check whether the valve of the pickup tube is normal, whether the jumper switch of the transmitter’s protection function is normal, whether the pickup tube is clogged or not, check the zero point and range of the white transmitter, and replace the sensing diaphragm head.
- Pressure variable reading deviation
pressure transmitter appears the phenomenon of pressure reading obviously high or low, first check whether there is a leakage phenomenon of the pressure-taking pipeline, and then check the valve on the pressure-taking pipe, fine-tuning of the sensor, if there is still a problem, replacement of the new sensing diaphragm head.
- Unstable reading of pressure variable
This problem can be solved by isolating the external interference source, checking whether there is leakage in the pressure guide pipe, whether there is any debris in the pipeline, checking whether there is any dress or deformation of the isolation diaphragm, and checking the pressure sensing diaphragm head.
