Problem with NI 9227

[GagruG]

I had purchased NI 9227 for current measurement. But is there any possibility to measure the current of 4-20mA range from a temperature transmitter by using NI9227, since NI 9227 have a minimum measurement range of 5A. 

[Henrik_Volkers · Accepted solution]

just give it a try 🙂

depending on the transmitted range and the needed resolution ... (you havn't told us 😉 )

the spec uncertaincy is quite high (for a 24bit unit) , but I assume that this is mostly due to the tempco and spec of the current shunt used in 9227, and you are using it only up to 20mA 🙂

another point is noise. but usually temperature sensors & signals are not very dynamic, so reading a lot of values for one or more seconds and calc the mean will help.

Of greatest help will be an individual calibration. a known current in the 20mA range or a known temperature near your max expected temperature  would verify your setup and enable correction. (More cal  points allow more ... ) 

  destilled water/ice give a 0°C usually good enough for industrial sensors, a stirred water bath at 37°C with a medical thermometer give a good second temperature point (medical thermometer (from a phar....   not *bay 😉 are a good calibrated! and cheap source for a temperature point)