These have to be the least accurate things I have ever seen.
The rectangular one is accurate or accurate enough and has been what I used but I noticed files all had cutouts for these round hygrometers…
Well from my 6 pack 1 is within a margin of error to even be useful.
I get they aren’t expensive but seems like a waste of money for this bad.
@Krauerking@lemy.lol Hygrometers are only as good as their components. Buying a DHT11/22 or SHT31 from AliExpress ($1-2) alongside an ESP8266/32 and you’d have much better results than buying these “are my cigars dry” pucks.
I’ve had massive differences in readouts in DHT22 from aliexpress. They are really not good sometimes
@callcc@lemmy.world SHT31/41 are better than DHT22 tbf. DHT would have a variance of about 2-5%. It also takes a while for it to stabilize.
Thanks for the tip. The BME280 are also not too bad.
@callcc@lemmy.world True - but it really depends what you’re measuring with BME280/680s though (680>280). As a combination temp/humidity/pressure they’re excellent, but for humidity alone I think SHT gives better “expected” readings than BME.
Someone nerded it out on arduino forums about five years ago: https://forum.arduino.cc/t/compare-different-i2c-temperature-and-humidity-sensors-sht2x-sht3x-sht85/599609/10