Is it vital to use sampling in RTD temperature measurements?

[Muori]

Hello

I am using NI 9217 module to acquire temperature measurements and I am wondering whether to use sampling or not. The examples that I found all use sampling but my own design doesn't. In my tests my own design works well and I would appreciate some insight on the importance of using sampling in RTD measurements. Could somebody point out where and why the example code performances better or is better than my solution. In my design I am using the while loop wait to control the "sampling rate".

I attached a picture where is a snipped from the example code (above) and a snipped from my own code (below), showing how the measurements value is acquired.

-LN

[Henrik_Volkers]

The DAQ driver is smart enough and use the default values that enable you to read a single value 😉

However by looking at your data you migth find that the temperature signal is more or less noisy for such a (usually) slow temperature signal.

The reason is the default setting of 1000SPS, so you 'randomly' peek at a 1µs value.

A better aproach would be to take more samples (say 300 @ 1kSPS) and take the mean value of it. Like that you eliminate most of the line noise (50Hz or 60Hz) ....