For some reason my air temp sensor is reading -9 currently in it's value grid, on my Omex 600.

I know it's nippy but it's not that cold... so presumably the calibration of the sensor is out of sync with the values in the ecu grid.

I've read up that it can be calibrated the same way as the water temp sensor. Has anyone done this tho? By putting it in water, heating it up and adding the temperature values as the temp increases?