exo-terra thermometer/hygrometer, any good?

I am looking at purchasing this combo to monitor the humidity and temperature inside of my incubation containers. I had purchased a Zilla combo with the individual probes, but the Zilla is 16% off in its humidity reading, when I did the calibration test.

To do the test, I used the salt and water test and left the sensors in the bag for 2 days to ensure accurate results. All hygrometers should have been reading 75% humidity in the test.

My test results were as follows:
Zilla- Temp:75F Humidity: 59%
Flukers- Temp: 75F Humidity: 75% +/- 1%
ZooMed Analog- Temp: 75F Humidity: 45%

I would use the Flukers, except I would like one with the probe so that I do not have to open my Hova to see the results on the Fluker's combo.

Not sure what this salt/water test is but whenever you are trying to do an experiment or study you have to do it many times to get an accurate scale. Not sure if this is what you did over the couple of days so I thought I would mention that.
Also have to have several of each product to really determine which one is better.... you might have bought a faulty zoomed hygrometer and not know it.
Otherwise very interesting results.

RampantReptiles said:

Not sure what this salt/water test is but whenever you are trying to do an experiment or study you have to do it many times to get an accurate scale.

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The salt/water test is a well established method for calibrating hygrometers. A dish of salt is saturated with water, then placed in a sealed bag or container with the hygrometer. The salt/water mix will hold humidity in the bag at exactly 75%, and the hygrometer is then adjusted to the proper reading.

Tony C said:

The salt/water test is a well established method for calibrating hygrometers. A dish of salt is saturated with water, then placed in a sealed bag or container with the hygrometer. The salt/water mix will hold humidity in the bag at exactly 75%, and the hygrometer is then adjusted to the proper reading.

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As Tony said it is very a well established method and is commonly used with cigar storage boxes to calibrate the hygrometers used to monitor the humidity in the box.

To calibrate a hygrometer you will need:

* 1/2 cup table salt
* approximately 1/4 cup water
* coffee cup
* hygrometer
* large re-sealable freezer bag

Mix the salt and water until the salt feels/looks like wet sand, then place the cup into a sealable bag, like a ziplock, and your hygrometer. Seal the bag and place it away from any drafts, sunlight or heaters. Let the hygrometer settle for about 8-12 hours, then take the reading. If accurate the hygrometer should be reading 75% humidity, good quality hydrometers are adjustable. Once you have your reading either adjust the hygrometer with the calibration dial or +/- the % needed for the hygrometer to read 75%.

So for my Zilla, it read 59%, I would then need to add 16% to my reading to get 75%. That means that any reading my Zilla takes, I then need to add 16% to it.

Be sure that the hygrometer remains dry and does not come into contact with the mixture for accurate results and to prevent damage to your hygrometer.