I. Wetted material
What we want to consider is the medium measured by the pressure transmitter
. The material of the contact medium part of the general pressure transmitter
is 316 stainless steel. If your medium is not corrosive to 316 stainless steel, then basically all the pressure changes The transmitter
is suitable for your measurement of the medium pressure.
If your medium is corrosive to 316 stainless steel, then we need to use chemical seals, which not only can measure the pressure of the medium, but also effectively prevent the medium from coming into contact with the wetted part of the pressure transmitter
. Protect the pressure transmitter and extend the life of the pressure transmitter.
Second, the accuracy level
Each type of electronic measuring meter will have an accuracy error, but because the accuracy levels marked by different countries are different, for example, the national standard accuracy such as China and the United States is the part with the best linearity of the sensor, which is our usual The accuracy of the measurement range is between 10% and 90%; the accuracy of the European standard is the worst part of linearity, which is what we usually call the measurement inverse 0 to 10% and 90% to 100% Between the accuracy. If the accuracy of the European standard is 1%, the accuracy of the Chinese standard is 0.5%.
The maximum range of the general sensor measurement is 70% of the full scale of the sensor.It is best to measure the pressure of 70 bar now.The range of the pressure transmitter we choose should be 100 bar.
Fourth, the output signal due to various acquisition needs, there are many output signals of pressure transmitters on the market today, mainly 4 ~ 20mA, 0 ~ 20mA, 0 ~ 10V, 0 ~ 5V, etc., but the more commonly used are There are two types of 4 ~ 20mA and 0 ~ 10V. Among these output signals I mentioned above, only 4 ~ 20mA is a two-wire system (the output we are talking about is a few-wire system and does not include ground or shielded wires). Three-wire system.
Five, medium temperature
Because the signal of the pressure transmitter
is partially converted by the electronic circuit, in general, the temperature of the measuring medium of the pressure transmitter
is -30 to +100 degrees. If the temperature is too high, we generally use a condensation bend to cool Medium, this will allow the manufacturer to reduce the cost of a high temperature pressure transmitter specially for you.
Generally we measure relatively clean fluids, we just use a standard pressure transmitter
. If the medium you are measuring is easy to crystallize or thick, we generally use an external diaphragm Or use it with chemical seal, which will effectively prevent the medium from blocking the pressure measurement hole.