HygroSet II Round Adjustable Digital Hygrometer for Humidors with Easy Calibration & 10 Second Refresh Rate | Precision Temperature & Humidity Monitoring for Enthusiasts - Battery Included

I read many reviews of all the available hyrgrometers before purchasing this one, and I took a "wait and see" approach, because I had some reservations. But after having purchased this product, I can say without hesitation that I am 100% satisfied. The device was close to spot-on accurate out of the box, and was pretty easy to re-calibrate once I got the hang of it. I would highly recommend either the pre-manufactured Boveda calibration kit, or else a homemade calibration kit, to aid in the calibration process. Here are some tips that I discovered along the way:1. When it comes to pressing the small reset button on the left of the hygrometer, which you have to press after turning the knob on the right to recalibrate the unit, I needed to use the tip of a pen (retracted) because trying to push it with my finger alone did not work.2. Maybe it's just me but after I read the directions (i.e. "Turn the knob one click in either direction to calibrate the hygrometer..." etc) I expected to see the numbers immediately change with each "click" that I turned the knob. It doesn't work that way. You have to turn the knob however many clicks you need to to get to the magic "75" (i.e. if it's reading 73 after a good amount of time in the calibration packet, you have to turn it 2 "clicks" clockwise; if it's reading 76, you need to turn it one "click" counterclockwise, etc.), press the small reset button on the left side, then put it back in the calibration bag, then wait a while to see if it ends up reading 75% R/H. Also, I never really heard any clicks. I had to find the larger "center" line on the face of the hygrometer, then see where the tiny little pointer was on the knob was, and adjust accordingly.3. As the instructions state, after you recalibrate and press the reset button, you have to press the red button to get back to F (vs C) if you're using F (and not C).4. The unit is very sensitive once it's out of the calibration bag, so you have to do the adjustments rather quickly then get it back in the bag a.s.a.p. so it can re-adjust itself and give you an accurate readout. Sometimes it takes more than one adjustment attempt to nail it at 75. It shouldn't take 24 hours by any means before it gives the actual readout; a couple of hours seemed to be the average on the units I purchased.I ended up purchasing 4 more after my initial purchase, and these units seem to be consistently well made. All 5 hygrometers work very well, and after the first one, they were all pretty easy to set up. Additionally, the thermometers appear to be quite accurate as well.

This is the third one of these I've gotten in just more than a year. They have been used in sheltered locations in blizzard conditions and in hot/humid situations where both the temp and humidity were in triple digits. In waiting a decent period of time before reporting the experience with them, I wanted to be able to give more than just a first impression.DESCRIPTION: The device itself is 1 3/4 inches diameter, 1/2 inch thick, with LCD readout (not backlit) that's 1/4 inch tall in a window 1 3/8 in wide x 3/8 in high. I think it's easy to read with adequate light. It's powered by a 357A button battery (less than 30 cents apiece if bought in a 10 pack on Amazon) which is accessed by a slide compartment on the back. The battery space is designed under the mounting area so it's easy to replace, although the original is still going strong after a year.MOUNTING: It comes with a crescent moon shaped magnet built into the back (it's lightly glued and can be removed if desired) and is quite strong and not easily dislodged from a decent metallic surface. An adhesive backed strip with a thin metal pad the same shape as the magnet is also included for use in placing a mount where a metal surface does not currently exist. The adhesive is rather weak and short lasting and I would suggest that double sided mounting tape be used if this method were chosen for a more secure fixture. There is no hole on the back for a nail hanging.FEATURES: The humidity reading is adjustable by a 3/8 inch diameter rotating dial on the lower right face. Each click of the dial moves the setting up or down 1%. The red button in the top center changes the temperature reading from Fahrenheit to Celsius and there is a small slightly recessed button on the lower left face that needs to be pressed to reset the humidity reading after the dial is moved. It's a safety measure I think because the dial is prominent and easily moved if the operator is not careful, or if children pick it up. Moving the dial without pressing reset does nothing. The temperature reading is not adjustable.RELIABILITY & ACCURACY: Straight out of the box all three of the ones I currently have were within 2 degrees of a calibrated laboratory thermometer at temperatures varying from 2 degrees F to 106 F. Over time they differ by only one or two degrees generally when placed within one foot of one another for a 24 hour period. Similarly, compared to a laboratory grade hygrometer, straight out of the box they were within 2 points reading humidity, and over time have maintained that degree of accuracy from an 18% to 100% saturated environment. It responds to small changes in temperature (less than 10 degrees) within 5 minutes and humidity (less than 20%) within 10.The main reason I chose this model over others was the adjustability of the humidity reading. Consumer grade humidity readers are notoriously inaccurate, even ones from famous "Scientific" manufacturers from Oregon. I did place each one in a 75% calibration environment (laboratory grade because it was available, but there are consumer ones available on Amazon that work fine for under $6) and each one read between 74 and 76%. So for the small sample size of 3 devices in my experience, none needed calibration. I tried the adjustment dial anyway, just for fun, and as advertised, one click = 1%. The clicks are subtle however, so be forewarned - you may turn the dial farther than you intend. The device responds quickly so it does not take long to correct your mistakes. Don't forget to push the reset button though, or your efforts will have been futile.SUMMARY: For the money this is really a very accurate and reliable piece of equipment. It has a major advantage over other humidistats in being adjustable. But I think its greatest advantage is that it comes from the factory actually calibrated, so it's accurate out of the box. For these type devices temperature has pretty much become a no-brainer - even $5 desktop penholders are pretty close. But I have found it rare that humidity readings are anywhere near accurate. For people looking for a temp/humidity sensor for wine cellars or cigar boxes or damp basements for determining when to run a dehumidifier, or dry air during the winter for a guide running humidifiers, this thing would suit well.

It was a little hard to get it adjusted, 3days, but now that it's all set it seems to work fine.