Beiträge von libreiot

  • Shelly HT erroneous readings

    Hello

    I have several (8ea) Shelly HT that I've setup and done some testing prior to installation that were bought recently and updated to latest firmware (20210413-154417/v1.10.2)

    First I put the Shelly HT's inside middle of a small room. For comparsion I've added other humidity and temp sensors, both analog hygrometer and digitals (Aqara's, NEXA).

    The temp readings of all sensors were within 0.5C so its more than good. But the Shelly HT's humidity readings in differed from 40% to 69% while the rest of the other sensors were in the range 54-57%

    This lead up to testing the sensors in a sealed controlled enviroment like you do with cigar humidor cabinets hygrometers.

    The test conducted have been performed in a plastic sealed container in two test rounds for ~24hrs each. First round in a 75% humidity / 23C and next 100% humidity/ 23C.

    First round (75% humidity reference) the Shelly HT's were between 80-100% (1ea at 80%, 4ea @ 100% and the rest around 90%) while the other sensors showed between 71% (Nexa) and 74% Aqara's (2ea) / Analog (1ea).

    Round two (100% reference) all Shelly showed 100%, as suspected! The NEXA showed 87%, Aqara's 97% and Analog 100%

    This seems good but makes the Shelly OFFSET function unusable as you cannot calibrate the offset difference and still make it show "more" correct readings in the full 0-100% scale.

    I have tried contact Shelly support and also create a ticket but still have got no replay regarding the humidity sensor drifting and if its considred normal this large and unconsistent offset. Of course its no precision sensor but the large fluctuations bewteen the HT's readings makes the humidity function kinda useless I think.


    Anyone else here at the forum have similar experience regarding erroneous readings of the Shelly HT?