[AllanG]

Until now, with the sensors I have, I was unsuccessful in trying to reproduce that behaviour. So, where the problem resides?
Sincerely I don't know! But must be something related to the sensor itself.

Yes, the problem with buying parts very cheaply from China is that we know only what the supplier tells us and we have no way of knowing whether it's true or not. Unless it's a very bad copy, I doubt it's possible to tell if there's a genuine sensiron chip on a board!

Since that one very brief occasion I've not seen above 100% recorded here. I'm going to try a little experiment though. A couple of months ago I bought a SHT25 on a small board which was sold and manufactured here in the UK, so I'm going to install that instead of the SHT21 from China. I'll leave the software as it is now and see if the SHT25 records anything over 100% during the next few months.

Maybe the lesson for us is that it may be a good idea to spend a little more money on some of the critical components to make sure we get genuine and reliable ones!

Happy New Year to the whole WeatherDuino family.

Allan.