I have several multisensors, and I’ve never paid a lot of attention to the humidity values. However, I’m trying to control humidity in several rooms now and am finding that getting a reliable humidity measurement is harder than I thought it would be.
See screenshot below - ignore the titles, I have put these all within ~2 inches of each other in the same room. Though they all follow approximately the same line, none of them agree, there’s a ~20% offset between the highest and lowest.
So maybe it’s not surprising they’re inaccurate given how inexpensive they are. But has anybody found a humidity sensor that is accurate/calibrated? And/or, I’m wondering if (to use these other sensors) anybody has just done an addition or subtraction adjustment to bring the offset sensors overlapping with an accurate/calibrated sensor?
Just so you know what the baseline is… most consumer grade electronic humidity sensors are going to have a 3-5% margin of error. Have you tested any other them?
I have about a dozen of the Xiaomi Bluetooth temp/humidity sensors throughout the house. I always test them as described in the link. IIRC, I’ve only had 2 that reported a value more than 3% away from 75% RH. The custom firmware makes it relatively easy to offset the value the sensor reports as needed, so there’s no need for template sensors etc in HA.
Thank you! That’s super helpful, to know that the baseline is 3-5%, which seems reasonable to me and is far from the ~20% I’m seeing. I’ll give that salt water test a try and see what I get. Appreciate the thoughts.
If you are going to say they are out of cal from each other, they need to be right next to each other for a reasonable period of time. You may have 20% difference in real humidity between a garage and a bedroom.
