During the winter months, we get calls from clients who's TIM10 or TIM12 CO2 monitors suddenly show an error code and can no longer read CO2 levels.
All the returned meters came from northern states (and countries) in the winter time. But when the monitors were returned to our factory in Florida, they worked fine.
After some research, we discovered is that the TIM10 and TIM12 CO2 monitors began displaying the error at 20% relative humidity or lower.
So if your TIM10 or TIM12 starts displaying an error during the winter months, check the humidity level reading on the meter first.