TFA Cosy Thermo-Hygrometer SG

In some ways this hygrometer works fine. It is very sensitive to changes in humidity and the readings are consistent. The display is easy to read, even at a distance.

The problem is that the readings are consistently WRONG. I've compared it with several high quality thermometers/hygrometers and the TFA "Cosy" Thermo-Hygrometer is consistently showing 2 degrees above and close to 10 % air humidity below all the others (the others all show more or less the same).

As long as I'm aware of this I can still use this hygrometer of course. It does seem to be very precise and consistent, just consistently WRONG. It seems to have a calibration issue rather than malfunctioning.

Still, it does not work the way it's supposed to so it will have to be a "poor" rating I'm afraid.

Having read reports about the effects of humidity on musical instruments, I was very concerned about my acoustic guitars. Although I live in a very damp British climate, having central heating on in the house for 6 months of the year is probably not good. I was rather shocked to discover how dry the atmosphere had become inside the house! The TFA Hygrometer gives a really quick visual guide, and helped me to remedy the situation by just opening a few windows to keep the humidity at a safe level. The Hygrometer is really sensitive - just hanging up some washing inside the house gives an instant change in the reading! Worth having one in different rooms.