Data logger calibration

Hellow dears,

I am trying to calibrate Rotronic data loggers Model HL-20 which is used to record temperature and humidity using a Testo brand Huminator II but I am not sure about the calibration tolerance. In other words what is the acceptance criteria in the calibration.

Appreciate your support if you can share any reference in this matter.

Temperature is an easy calibration. RH is more problematic. In my experience a +/-2% RH was as tight as my metrology person would commit to, but we didn’t have a Testo Huminator II.

I just checked the cut sheet for the Testo Huminator II. It states that “typical” accuracy is +/-1.5 %.

Here is the web page for that unit.