Hi, I am fairly new to this and am having trouble with noisy signals being received from a 9203 module in the range of +- 20KPa (2.9 PSI) measuring a 4-20mA, 6895 KPa (1000 PSI) pressure sensor output across it's operating range.
When injecting a clean signal from a Fluke 725 calibrator the noise level is the same if not worse, however if I connect an analogue input to the power supply +ve rail via a resistor to bring the signal within +-20mA, the signal noise is the equivalent of +-2 KPa.
I don't know exactly how these modules work and am wondering if it could be caused by lack of common mode noise in the measurement circuitry. If anyone could provide advice on what could be the cause of these results it would be greatly appreciated. Are there any in depth diagrams available detailing how the 9203 cards work? Ideally I would like to understand what happens inside the card itself for future reference as well.
Cheers.
Rory.
