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Caliber III Thermometer Hygrometer by Western Humidor
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List Price: $24.95 Our Price: $15.40 You Save: $9.55 (38%) Availability: Usually ships in 1-2 business days Category: Home See more product details
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Product DetailsManufacturer: Western Humidor Brand: Western Humidor Edition: Kitchen Model: CALIBER3 Publisher: Western Humidor Studio: Western Humidor Music Label: Western Humidor Product features: - Never requires calibration
- Easy to read large display
- Magnetic mount
- Accuracy +/- 1% humidity, +/-1 degree temperature
- Dimensions: 3.5" x 1.25" x .25"
Tools and Hardware Reviews of Caliber III Thermometer HygrometerCustomer Review: Humidity measurements Summary: 4 Stars
A couple weeks ago I bought a Caliber III digital hygrometer/thermometer, and liked it quite a bit, so I bought 2 more, for a second room & inside a guitar case.
I want to make few comments on their accuracy, and suggestions for testing accuracy of rh measurements with these gadgets.
The bottom line is that measuring & interpreting relative humidity (rh) isn't as simple as you might think. There may be some defective units out there, but if you jump to conclusions, you might be discarding a perfectly good hygrometer.
The tests I did, and why:
I wanted to know what range of humidity my house has, because in the winter I get headaches if it's too dry. I chose the Caliber III digital hygrometer/thermometer because of its specifications, and the strong reviews. From the manufacturer's website:
Humidity Measuring Range 20% to 99% RH (relative humidity)
Resolution 1%
Accuracy, humidity ....... +/- 1% (40%-80%) +/- 3% other
Updating time 10 seconds
Temperature Measuring Range to 50 C/ 32-120F
Resolution 1 degree
Accuracy +/-1 C/F
These aren't quite the same as the specs posted here, which apply to humidors @ ~ 75% rh: but below 40% humidity, which is what I expected in my house in winter, the accuracy in +/- 3%, not +/- 1%, but plenty good for my needs, and below 20% rh they aren't going to be much use, except to let you know that the air is very dry.
Suppose you put two units next to each other to compare their readings: wait a few minutes for the units to adjust ...if readings are not the same, say 31% (unit A) and 26% (unit B)...does this mean that A will always read higher than B, or is this because there are slight differences in humidity even within a few inches? Unit A may read higher than B, but because 31% +/- 3% overlaps with 26% +/- 3%, in fact the difference isn't reliable.
With a little fussing, you can find out: swap the two units (put A where B was & vice versa), allow time to adjust, and take another set of measurements; or, use a gentle fan to circulate the air, so there is little chance of variation in the actual humidity between the two. Another possibility is to increase the humidity (with a humidifier or wet sponge and a fan to circulate the air) and watch the measurements of the two units climb over several minutes. If unit A consistently reads higher than B in all these conditions, then they are calibrated differently.
Problems interpreting humidity get exaggerated when you try to take measurements in an enclosed space (guitar case, humidor, terrarium), especially one that contains things (like animals and plants) that take up water and release water. What one naturally expects to be the case, that the air in a room/ terrarium/ guitar case has a particular % humidity and that it doesn't vary much from place to place, is probably wrong most of the time. This assumption comes from the facts that 1) Except for on our face, most humans are not very sensitive to small (+/- 5%) changes in humidity, and 2) some of the classical devices for measuring humidity, like sling psychrometers, in fact report measurements that are averaged over time (~30 sec) and a large volume of air (several cubic yards).
These little digital devices make more precise, more sensitive, and much more localized measurements. Taken together, this makes it pretty hard for a human to anticipate what level of rh a finger-sized electronic device will detect.
In other words, we really don't know how much variation there is in rh until we measure it with sensitive devices under different conditions.
What I found was that the 3 Caliber III's and another similar item I got from Radio Shack a few years ago are all within specs. They don't always register below 20% rh... when the humidity goes below 20% (out of range), the display sometimes reads "---%", and sometimes it reports a value, like 11%, but there is no way to know how accurate (or not) this is. Otherwise, in the range I tested they were within 3%.
Description of Caliber III Thermometer HygrometerThis Western digital humidor gauge accurately measures and displays relative humidity and temperature to assure your cigars are stored in the ideal conditions keeping them in prime smoking condition. The Caliber III never requires calibration; there are no springs to stretch or moving parts to wear out. Features easy to read large display, slim profile design, and magnetic mount. Accuracy +/- 1% humidity, +/-1 degree temperature. Full 5 years guarantee. Dimensions: 3.5" x 1.25" x .25".
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