Mini Power-Free Indoor Outdoor Humidity Easy To Read Water Resistant Unit

Excellent product. Exactly what I was looking for. Bought a half dozen of them, to be able to spot check various zones throughout my property (garage, back deck, inside living spaces, HVAC Utility room. Knowing our humidity is a medical necessity in our household, as one of us has MS which is very fickle with temps & humidity. These devices well priced, I added self-stick hook/loop (Velcro) to them so I could easily stick them anywhere I needed.

This hygrometer was only about $2 & worked just as well, if not better than, a fancy one I got for $70. It had accurate readings for several months until I put it inside of my mini greenhouse where I have mushroom blocks growing. After about a month or 2, it got stuck & stopped working. Not sure if it was TOO humid in the mini greenhouse or what killed it. You would assume a humidity meter would be able to handle a humid environment...🤔 Anyway, the other bad thing about it is that it was shipped from China in a tiny bubble wrap package & the front was busted when I got it. I informed the company & they immediately refunded my money, no questions asked, so that part was good. Despite the front being busted from shipping, it still worked perfectly tho.

Got 3 of these. When side-by-side, they differ 10 to 15% in their readings, so don't know which one is most accurate! They are responsive and clearly show when humidity changes and are very interesting to watch, but don't have much confidence in absolute accuracy.

I ordered four of these. I wanted to check humidity in various areas of my home. But I kept them together in one spot for a day to see if they were consistent, and then placed them at various locations around the house. They are consistent and agree within a few degrees of measurement with each other and my other meter. They aren't very large, just over two inches or so across, but I wanted them to be inconspicuous. They have a slot on the back for mounting using a small nail, but I just used some double faced tape, as the don't weigh much. The tape will hold them OK. No batteries, no lights, no fuss, no maintenance. Just a dial. They were shipped promptly and it took only a couple of weeks to get here. Overall, I am happy with these meters.Note; they say don't run a dehumidifier with central air, but I run two 70 pint dehumidifiers; one in the basement and one upstairs, and they do a great job of getting that humidity down. It is difficult to properly size a central air unit in my area. If it runs enough to get the humidity down on an 85 degree day it is not capable of cooling properly on our 100 degree days. So my central AC is sized to handle the hottest days, but we can get a lot of humidity even on a 75 degree day. But the AC then doesn't run enough to reduce that humidity much; hence the dehumidifiers. I bought the dehumidifiers because I got tired of turning down the AC simply so it would kick on and reduce the humidity even though the temperature in the house was fine and I didn't really need it any colder. It was just too humid. The setup with the dehumidifiers has solved that problem.

I bought two of these, and the humidity readings differ by about 8 percent. The lower one reads about 2% higher than a digital hygrometer I already had. The price is good, but the factory quality control is not good. If you want better than +/-5% accuracy, you may have to buy several of these (or compare them with a known good hygrometer), and throw out the inaccurate ones.Humans cannot feel the difference of a few percent humidity. I believe I can start to feel the difference when the humidity changes by at least 10% or 15%. If you want good accuracy, buy a more expensive, well-calibrated, scientific instrument.

I've sat these next to 2 other digital thermometers with humidity gauges, and these little analog ones give readings that are consistently within the same range after switching them around, so working as expected. Hard to beat for the price!

This is really inexpensive, but like others reported its %RH is off, in my case its 10%.Time will tell whether it's stays at 10% or if this will vary. Frankly, I would not buy this again.Edit (12/14/2017):These varies quite a lot in the sense that it is not a linear 10%, across all ranges, but the dryer it gets, the higher the discrepancies. Basically these have very limited range.I just bought a new digital reader for $9 with 4+ stars reviews. And I am not planing to buy this one ever again.

Item seems accurate, calibrated against an electronic humidity meter. It is actually much smaller than it appears in photo illustrations, about 2 inches in diameter. Build quality sloppy; mounted on wall, the label is crooked, so there's no mistaking it for a quality product. Imported. But the main thing, it does the job of measuring humidity, and it doesn't need batteries.