Problem with pressure transducer

[spintinas]

Hello, my problem is related to pressure transducer. I have a pressure transducer Data Instruments (now Honeywell) AB model 25 psi. Datasheet is here: https://stevenengineering.com/tech_support/PDFs/31DTMAIN.pdf . (My transducer in datasheet is first, AB model). Problem is, that when I power this transducer from usb connector, transducer didn't work correctly. When there is no pressure, I get the 2.5V DC voltage in my multimeter, but according to datasheet Zero Output is 0 + 5 mV. Also, when I pressure transducer there is no change, anyway 2.5V from transducer. In my opinion power source is good, because voltage between Excitation+ and Excitation- is 5V. So, maybe anything of you know what problem it can be?

[BradC]

Hello, my problem is related to pressure transducer. I have a pressure transducer Data Instruments (now Honeywell) AB model 25 psi. Datasheet is here: https://stevenengineering.com/tech_support/PDFs/31DTMAIN.pdf . (My transducer in datasheet is first, AB model). Problem is, that when I power this transducer from usb connector, transducer didn't work correctly. When there is no pressure, I get the 2.5V DC voltage in my multimeter, but according to datasheet Zero Output is 0 + 5 mV. Also, when I pressure transducer there is no change, anyway 2.5V from transducer. In my opinion power source is good, because voltage between Excitation+ and Excitation- is 5V. So, maybe anything of you know what problem it can be?

Where are you measuring from. You need to measure the voltage difference *between* the two signal wires. That should be ~0V at rest and ~100mV at full pressure. Their relationship to your excitation wires is arbitrary and not important, although they should be sitting somewhere around half (which they appear to be).

[babysitter]

If you are already measuring between both the signal pins, the unit is damaged. Sometimes pressure transducers die with one half bridge basically OK, the other half bridge tied to excitation + or -.

[danadak]

The xducewr is a bridge type interface -


http://www.analog.com/media/en/analog-dialogue/volume-38/number-2/articles/bridge-type-sensor-measurements.pdf


http://www.ti.com/lit/an/slyt640/slyt640.pdf


http://cds.linear.com/docs/en/application-note/an43f.pdf


Regards, Dana.

[spintinas]

So, now I check again, and I see that voltage between data signals is ~65mV, in datahsheet i saw, that my transducer is absolute pressure. So, when I try to measure pressure from my blood pressure pump, I see voltage 65mV, which equal to 14,7 psi (atmospheric pressure). 25psi - 100mV, 14,7psi ~50mV, i came to conclusion, that transducer works correctly, but now I have a question, how to perform pressure measurement with this transducer? It's there some ways to callibrate them or any onther options? When I apply some pressure on transducer, still I get value of 65mV (atmospheric pressure).

[babysitter]

Please state the exact type! The front membrane is the sensitive area.