The daily maintenance of pressure transmitter

- May 20, 2020-

   Pressure transmitter is a commonly used detection instrument, mainly for the measurement of liquid, steam, gas and other media, and is widely used in many industries. The transmitter adopts imported high-quality diffused silicon or ceramic pressure sensors as sensitive components, and uses a special integrated module, fine temperature, zero point, full range and nonlinear compensation to achieve accurate measurement of pressure changes in liquid, gas, steam and other media.  

At present, the transmitter is widely used in various industrial automatic control environments due to its simple structure, ruggedness, high stability, high accuracy and good linearity characteristics. It has a wide measurement range and is used in water conservancy and hydropower, railway transportation ,production automation, aerospace, military, petrochemical, oil well, power, shipbuilding, machine tool, pipeline and many other industries.

The daily maintenance of pressure transmitter should do the following work: 

Prevent leakage

   If the fittings, valves, and three valve groups used with the pressure transmitter are leaking, it will cause measurement errors. Liquid or steam is easy to find leakage. Soap water can be used to check the leakage point. Observe whether there is any leakage in the exhaust drain plug of the pressure guiding pipe joint, card sleeve joint, valve joint, transmitter high and low pressure chamber.

Anti-clogging 

   Blockage often occurs in the pressure guide pipe and valve. When there are impurities in the pressure guiding tube or valve of the pressure transmitter, the pressure will not be transmitted smoothly, and there will be a hysteresis in the measured value of the transmitter, which cannot reflect the change of process pressure or flow rate in a timely and true manner. When the blockage only occurs on one pressure-guiding pipe, the output signal of the transmitter will be too large or small, and the fluctuation of the measurement signal will be significantly reduced. Sewage and flushing of the pressure-guiding pipe shall be carried out in strict accordance with the regulations. It must be handled in time to ensure the smoothness of the pressure-guiding pipeline. 

Anti-corrosion

   The environmental conditions on site are poor, and most of the measured media are corrosive. According to the measured media, the structural material and the sealing ring of the transmitter  should be correctly selected. When measure liquid and water, the pressure guiding tube and the transmitter measurement room should be insulated heat tracing measures; if the temperature of the measured medium is too high, it is necessary to protect the measuring chamber and the diaphragm with an isolation liquid; isolation measures must be taken when measuring corrosive media. Choose the installation location of the transmitter reasonably. The transmitter installed on site must have a protection box.

After opening the transmitter shell for debugging or maintenance, the shell must be tightened. If the shell is not tightened, the circuit board will be eroded by moisture and rain, which will damage the circuit board or reduce the insulation performance and cause the transmitter to malfunction. The lock nut is connected with the housing and the high and low pressure measurement chambers with sealant. After disassembly, the nut should be tightened and the sealant should be reapplied.