pressure transducer

[sahand]

I am using a national instruments NI-6221 multifunction DAQ with a SCC carrier, SC-2345 signal conditioning with configurable connectors, with LabVIEW software to acquire data. I am able to get data for all the inputs except pressure. the pressure transducer which I am using is an ASHCROFT DRESSER INSTRUMENTS model K1 , and I checked it and it is ok. but the data that I am getting for pressure are negative numbers and almost constant. I appreciate it having your advice.

thanks

Arshad

[ssk]

Are you sure the transducer is working correctly? Measure the output directly using a multimeter.

Check that the input to the DAQ device is working correctly by applying a known voltage.

Check that your wiring is correct for the ipnut setting of the DAQ device (single ended, differential etc).

[AnalogKid2DigitalMan]

Does the transducer have 2 or 3 wires coming out of it? If only 2 then it is the 4-20mA current loop variety. I did not look at the specs of your NI hardware, I am assuming your hardware accepts voltage inputs. You would need to add a resistor in parallel with your DAQ input to convert it to a voltage signal the card can read.

-AK2DM