My icc500t is reading 3500ppm+ ambient! I’m alive so it must be erroneous!!!
Please check that the probe, the white sticker on the probe, and the probe cable are intact?
If the probe is plugged into another probe port and tested in a dry stable environment, will it still read off?
If yes, please send an email to firstname.lastname@example.org with order information and a picture of the problem.