Differential Pressure Units / Manometers

Hey everyone. Got a question that I need help with please...

I have some differential pressure units (aka manometers) attached to each flow recorder; used to determine/regulate gas flow/pressure on oil and gas wells. Are the DPU's/manometers electric "motors"? They require DC power and are rated at 2500 psi. That's about all I know about them...

Any information would be great. I have done research but can't seem to find any answers.

Here is a link to a pdf of one of the flow recorder models. The manometer is located on the backside of the case. www.petersoninst.com/pdfs/DRIFLOII/DF2 Manual.pdf



Thanks a million

Didn't really read to far into the PDF but the voltage is probably required to operate the recorder. There is a good posability that the recorder operates with the monometer through a 4-20 MA circuit. The more the flow of gas the higher the MA reading will be sent to the recorder and that tells the recorder what to print.