Review on Precise Humidity Control With Xikar PuroTemp Round Digital Hygrometer, 10-Second Refresh Rate by Alejandro Silem

Easy to calibrate but that is also this gizmo's biggest flaw. After 4 hrs in a wet salt environment in a ziplock bag, just tap the Calibrate button, remove from bag and done. Doesn't get any easier. I have 4 of them. Have periodically put all 4 in the same environment, RH & temp readings have always been identical in all 4. Good way to also test the analog hygrometer. This consistency is why I give it 5 stars despite flaw mention below.BUT . if you accidentally touch the Calibrate button afterwards, which is easy to do because the button is not recessed and is right next to the C/F temperature button, or when you're loading in extra cigars or your shirt sleeve brushes against it, the LED will instantly change to 75% regardless of actual humidity. So now you have to recalibrate it all over again or remember how much to +/- to get an accurate reading.In other words, if you take the hygrometer out in say a dry 45% climate to add some cigars or refill the humidifier, accidentally hit the Calibrate button when placing it back in, it'll read 75% but will actually be 30% degrees off until you recalibrate it. And since all you have to do it tap it, not press & hold it for several seconds, you can easily happen to hit the Calibrate button without even realizing you did it.Not a problem if in a locked humidor and you're the only one that has access. But I would not trust it in a travel case or if you separate cigars in ziplock bags even for temporary storage or moving as you'll have no idea whether something accidentally bumped the Calibrate button while your luggage was being bounced around. Even bigger problems if you share a humidor, have kids that like to snoop around, or you bump a full humidor while cleaning & the hygrometer falls on a cigar. Was the Calibrate button accidentally tapped?Great unit if you're careful to look but don't touch. I still recommend re-calibrating once every month or two by taking the battery out, letting it reset and re-doing the salt test.