How to adjust temperature measurements ? Topic is solved

[CharlesL]

I have several temperature sensors hooked up to Domoticz, and I'd like to adjust the sensor readings to reflect some form of calibration. E.g. a sensor-specific calibration constant.

For illustration see the graph below, which shows temperature measurements taken by 2 separate sensors (different makes) that are 1 cm apart.

Measurements

chart.png (135.47 KiB) Viewed 1494 times

Of course the measurements should be identical, but there is a systematic offset of about 0.3 C - 0.5 C. That's not unreasonable for consumer-grade thermometers, but it's annoying and unnecessary because it's also something that can be easily remedied through calibration.

Of course I don't know which one is correct, but I want to at least make them consistent (so that when I put them in different rooms I won't be told that one room is always 0.5 C cooler than the other). Besides, I can always borrow a thermometer that's guaranteed accurate, and use that reading to calibrate both other sensors.

The question is: how to calibrate the thermometers or adjust the readings?

I can't calibrate the devices themselves (no technical manual, no API, etc.), so I'd have to adjust the readings after they're made. I.e. probably after they're received by Domoticz.

Any suggestions on how I can do that?
Does Domoticz itself offer a service like that? If not, how and where could I tweak Domoticz to do that? I believe it would be a reasonable feature for Domoticz to have.

[manjh]

Go to the "temperature" tab and find the device.
Then "Edit" it, and insert the correction value in the "adjustment" field. That should do it.

[CharlesL]

@manjh

Great thanks. I overlooked it.