Voltage Input Module selection for cRIO

[BonAn]

Application:

- Differential voltage input reading for 12 voltage taps

- Signal is 20 uV to 10V level

- Acquisition speed = 1 kHz

- Can be up to 3 separate modules

Desire:

- Minimal noise, drift, etc.

- Reliablilty

So far, have used 24-bit modules w/ 10V range. Originally used three of the 9239 modules which worked fine but had the upper limit of noise on the uV level. Swapped to a single 9202, which seemed to have lower noise when utilizing the filter, but this module has been very unreliable. Three of them have failed on two different systems with minimal usage, whereas the 9239 cards have never failed. 

Additional modules options I have found: 9224 and the 9252.

Which module (9239, 9202, 9224, 9252, or any other recommendation) will be the best for my application, and how do they compare on the baseline noise level at 1kHz ?

[BonAn]

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[santo_13]

What kind of signals are those from the tap? Are those a voltage divider/attenuator from a high voltage? Do you intend to read DC or AC (frequency content) signals?

What is your required resolution and accuracy for these 20uV to 10V signals?

[BonAn]

- It is a voltage tap on a superconducting wire. As such, the voltage is extremely low until the wire transitions from the superconducting state

- The superconducting wire is being ramped up with DC or low frequency AC power until transition. So the signal on the voltage tap is usually DC, sometimes <1 Hz AC.

- It is not voltage divided

- Not much help, but the higher the resolution and accuracy, the better; but keep in mind the 1 ms data rate