PCI 6033 Analog measurement noise

[auerdoan]

I want to make sure I'm doing all I can to get the best measurement possible

Im using a SCB 100; I'm using a PCI 6033 card.

I've connected my analog wires

Looking at a chart labeled I/O connector for 64 channel E series Devices..

I see for ground a choice AI GND, AI SENSE, AI SENSE 2, EXT REF, AO GND, D GND.

I used the AI GND.

my measurement is close but there is some noise 4.30 milliamp is expected I'm getting 4.80 on some units 

in Measurement and Automation I've set it up for ref single ended and a -10 to 10 vdc measurement

I connected a wire from the AI GND to my units I measure power supply ground the wire is short less than 10 inches, 16 gauge.

Am I using the correct ground?.

Thanks-Kurt

this post is also in the Labview forum i think it belongs here.

[CWolf · Accepted solution]

Kurt,

Yes, that is the correct ground for an RSE measurement.  Is your signal source floating or grounded?  If it is grounded then I would recommend using differential or NRSE instead of RSE.  Here is a document that is a great reference for wiring and noise considerations. 

 -Christina

[auerdoan]

I did find the problem in our software someone had put a offset in our measurement that wasn't necessary in the test system.

The software was copied from another system and modified to work with this one and they didn't realize a offset wasn't necessary.

I wish I could go differential in all our measurements but because of cost we make due with single ended unless absolutely required.

Thank you for the link very useful.

I also changed my Measurement and Automation to 0-10 instead of -10 to10   

Thank you -Kurt