Is it possible to use a 9217 to measure 30 kΩ thermistors?

[JoshB]

I have a 9217 (100 Ω RTD, 24-Bit Analog Input Module).  Can it be used for measuring thermistors that have a resistance of 30 kΩ at 0C?  They require an excitation current of between 10-15 uA.

The 9217 module: https://www.ni.com/en-us/shop/model/ni-9217.html

[Henrik_Volkers]

Without digging into the spec in detail, you have a current source of 1mA and you can measure a voltage in the range of 0-400mV...

Depending on the uncertainty you need the most simple solution is a good (stable, low tempco) resistor parallel to your thermistor.

Depending on your temperature range (thermistor value) and the max current you can choose a value for R to stay in the 0-400 Ohm range.

[JoshB]

It's not clear from the spec, but can the current source be changed to values other than 1 mA (such as 10 uA)?

While I have the hardware, I ordered the wrong USB sleeve, so I can't test this out myself until the new sleeve comes in.  For some reason, the 9217 is not available to be simulated in MAX, or I would just set up a simulated instrument and see what options are available in the task setup.

[Brad_K · Accepted solution]

Hi JoshB,

The excitation current on the NI 9217 is fixed, not programmable.

To create a simulated NI 9217 in DAQmx, you need to create a simulated CompactDAQ chassis first. Then right-click on the chassis and there will be an option to configure simulated modules.

Brad