Differential pressure transmitter


I have an application where the vessel will be compressed and vacuumed with air at different times. I would like to know if i can use the diferential pressure transmitter and get the -ve to +ve kpa readings. We need to measure -50kpa to +50kpa and feed the output as 4-20mA to PLC for some control.

You do have to ensure that the particular pressure transmitter model is capable and calibrated for both gauge pressure positive pressure and vacuum. While all gauge pressure transmitters handle positive pressure, some are not characterized or calibrated into the vacuum pressure range. The spec should say the the LRL (Lower Range Level) is -1.0bar or -14.7psi Eng units are selectable on smart transmitters and the output range is configurable to your range.

Do not let any vendor tell you that you need an absolute pressure transmitter, this is not an absolute pressure application.