Potential Analog Input Offset Using an Externally Powered Pressure Transducer in an SCXI SystemHardware: SCXI
Problem: I am using an SCXI system for analog input (for example an SCXI-1100 with an SCXI-1300 terminal block) and measuring voltage from a pressure transducer that requires an external power source. Why do I see a constant offset over the entire range of my measurement? Solution: Because the pressure transducer is externally powered, it is a grounded signal source. When this grounded signal source is connected in differential mode to the SCXI system, the offset observed is actually the potential difference between the source ground and the measurement system ground. To account for potential difference between the source ground and the measurement system ground, place a bias resistor from the AI negative terminal to ground on the SCXI terminal block. Related Links: Field Wiring and Noise Considerations for Analog Signals . Attachments:
Report Date: 07/16/2004 Last Updated: 07/19/2007 Document ID: 3BFCPR1J |
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