We were trying to decide if humidity levels were an issue in our house. Very often, modern houses strive to be so insulating what with A-rated windows, thick loft lagging, plaster walls etc. There is little opportunity for newer houses to breathe properly, so it can give the impression of the air feeling overly "dry", which can lead to respiratory issues. We always seem to wake up feeling like our eyelids are made from sandpaper, so figured a hygrometer might at least give us an indication of what the state of the house was at any one time.
There are loads of these things on the market, from analogue to digital, full weather-stations to single-purpose devices. I settled on this model from TFA because I liked the idea of it giving a high and low for both temperature and humidity over a set 24 hour period. I also thought the Germanic pidgin-English from it's description was endearing - and continues in some of the documentation.
There isn't much to this device, but once you've figured out it's relatively limited controls, you can set it to "reset" it's high and low readouts at a designated time of day. I set mine to reset at 08.00hrs, so that I can see when I wake up at half 6am what the entire previous 24 hour period including the night I have just slept through what sort of extremes I might have been succomb to.
As it turns out, our house actually has very good readings, frequently over 60%. I understand that 50-55% is considered optimal, and any higher is all-the-better, but you have to be wary of condensation and potential mildew formations if it goes too high.
The model comes in your chosen coloured rim. I opted for the orange because I had no issue with it's quite trendy overall appearance. I haven't been disappointed.