Can I measure voltage only signal with NI 9211

[ping2002]

Hi,

I have some low voltage signals to measure, ranging from 10mv to 80mv, I am using NI 9205 voltage input module now, but the accuracy is only about 1% or worse, that is below my expectation. I am considering NI 9211, which is said to be able to measure "4 thermocouple or ±80 mV analog inputs".
 
My 1st question is, can I use NI 9211 to measure these differential low voltage signals? I do not need the CJC and autozero function in 92111, but only need the voltage value. These signals are not from thermocouples, they are differential voltage signals from 7-100 ohm resistors.

My 2nd question is, what is the voltage measurement accuracy of NI 9211, its manual does not specify the voltage measurement accuracy, it only listed the converted temperature measurement accuracy.

My 3rd question is about the NI 9974 36-pos spring term connector block for NI 9205, I have 16 pairs of wire connected to the spring terminal on NI 9205, which took a long time to attach and detach all the wires. NI 9205 need to be sent back to NI for calibration, I do not want to detach those wires before shipping it back to NI and attach those wires back after it is shipped back.

I am wondering if I can use an extra NI 9974 for this purpose. Can I unscrew the two side screws on the  NI 9205 spring terminal, and pull it out, then plug in the extra NI 9974 spring terminal with no wires attached,  send it back to NI for calibration? I had tried to pull out the current NI 9205 spring terminal block with the two side screw loosened, but the terminal is very rigid, hard to pull out, I gave up, being afraid too much pull force might damage the connector. I am wondering if this connector terminal is designed for pull out, please advise.

 
Thanks a lot.

 

Ping

[KateB]

Hi Ping,

1. Yes, you can use 9211 to measure a voltage, I used it with pyranometer before.

2. Please refer to page 20 of http://www.ni.com/pdf/manuals/371566e.pdf.

3. Yes, this connector can be pulled out.

Regards, Kate