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.
I would not be at all surprised to learn that both the commodity round and rectangular units use the exact same components inside. These surely must be made from jellybean off the shelf parts, and at similar price points to each other neither could possibly be assembled with much care or attention to detail.
I have a six pack of the rectangular ones from Jeff Bezos’ Knockoff Whitebox Emporium. Even all sealed in the same container with each other, they all disagree by a spread of about 15%. I have no idea which of the six, if any, are actually producing an accurate number.