Hi,
I'm having an issue on acquiring signals from a pressure transducer (PT) using NI cDAQ and module NI-9237 AI bridge that has a span of 0 - 10mV/V output voltage which equivalent to 0 - 30,000psi. The excitation voltage needed by the PT is 5 - 15V. The PT configuration is a full bridge.
When applying either 10V internal excitation (from RJ50 pin 6 and 7) or 10V external excitation (pigtail connector), the output signals from the PT does not increase when pressure is applied using DAQmx in LabVIEW. In contrast, when I measured the output signals using a digital multimeter, the reading shows perfectly fine.
When I decrease the excitation voltage (either internal or external) to 5V, the output signals now shows reading when pressure is applied but still it is not correspondent to the reading that is acquired using digital multimeter.
The PT has been sent for calibration and worked well. But then I re-test again the PT using the previous setup and the result is still the same. I also replaced the NI-9237 module with other unit and still not working. Could there be a possibility that NI-9237 has limitations?
I have also attached a PDF slide on what I have tested and the result of the test.
Can anyone assist me on this issue? Feel free to ask me more if you need any further intel to help me on the testing. Please, and thanks in advance.
