1. Measuring medium
If the measurement is relatively clean fluid, the standard pressure transmitter can be used directly. If the measured medium for the high viscosity easy to crystallize strong corrosion occasions, it is necessary to choose the isolation type transmitter. When selecting the type to consider its medium on the corrosion of the membrane box metal, be sure to choose a good membrane box material, otherwise the use of a very short period of time after the corrosion of the outer diaphragm, the flange will also be corroded resulting in equipment and personal accidents. Transmitter diaphragm box material has ordinary stainless steel, 304 stainless steel, 316L stainless steel, tantalum diaphragm box material.
2. Range range
From the selection of transmitter measurement range, the general transmitter has a certain range of adjustable range, it is best to use the range of range is set in its range of 1/4 ~ 3/4 paragraph, so that the accuracy will be guaranteed, for micro differential pressure transmitter is even more important. In practice, some applications need to migrate the measuring range of the transmitter, which needs to be calculated according to the field installation location of the measuring range and migration, and then positive migration or negative migration.
3. Accuracy level
Each measuring instrument will have accuracy error, but because of the accuracy level of each country is not the same, for example, China and the United States of America is the accuracy of the sensor in the best part of the linearity of the sensor, that is, we usually say that the measurement range of the accuracy of the 10% to 90% of the accuracy; and the accuracy of the European standard is the most bad part of the linearity, that is, we usually say that the measurement range of the 0% to 90% of the accuracy; and the accuracy of the European standard is the most poorly linear part, that is, we usually say the measurement range of the 0% to 90% of the accuracy of the sensor. The European standard accuracy is the part with the worst linearity, that is, the accuracy between 0% and 10% and 90% and 100% of the measuring range, as we usually say. If the precision of the European standard is 1%, the precision of the Chinese standard is 0.5%.
4. Catch liquid material
General pressure transmitter contact media part of the material used is 316 stainless steel, if the measurement medium is not corrosive to 316 stainless steel, then basically all the pressure transmitter is suitable for the measurement of the medium pressure; if the measurement medium is corrosive to 316 stainless steel, then we must use the chemical sealing, so that not only measure the pressure of the medium, but also to effectively measure the pressure of the medium, and also to effectively measure the pressure of the medium. Medium pressure, but also can effectively prevent the medium and the pressure transmitter between the liquid part of the contact, so as to play a role in protecting the pressure transmitter, to extend the service life of the role.
5. Output Signal
At present, due to the need for a variety of acquisition, there are many kinds of pressure transmitter output signals on the market, mainly 4~20mA, 0~20mA, 0~10V, 0~5V, etc., the more commonly used is 4~20mA and 0~10V two kinds of, and only the 4~20mA signal for the two-wire system (excluding grounding and shielding), the other are three-wire system. Other are three-wire system.
6. Medium temperature
Because the signal of the pressure transmitter is converted through the electronic part of the circuit, so in general, the pressure transmitter measurement medium temperature of -30 to +100 degrees. If the temperature is too high, the general use of condensation bend to cool the medium.
7. Other
After determining these parameters above, but also to confirm the process of pressure transmitter connection interface and pressure transmitter power supply voltage; if the use of special occasions to consider the explosion-proof as well as the level of protection and so on.
To learn more about the transmitter information, you can consult the Mack Sensors Co!