Coolidor question

Is he using a digital hydrometer?

I read on another forum there may be an issue with some digital hydrometer. If the temperature is 67 F or less, then it adds 5% humidity to the real humidity. If the temperature is more at 68 or more, then it is the correct humidity. There was a thread I think on ICC.

I purchased the round digital meter from heartfelt and tested it and found this to be true.