For years I have used an Caliber III Hygrometer to monitor the temp and humidity in my safe. It was regarded as a very good hygrometer for the price. It has worked fine, but I have always wondered on how accurate it really was. Recently, I had a deal that I could not pass up on and I bought a Golden Rod wireless digital hygrometer by Battenfeld/Lockdown. It had good reviews plus I liked the feature about being able to measure the temp and humidity from inside the safe on a display monitor on the outside of the safe. First I did a simple test. I took both hygrometers outside the safe and left them on my desk for 24 hours. The temps matched up, but the humidity percentage was way off. Then I placed them back into the safe and waited 48 hours. The temps matched up again, but the humidity was still way off. For example, the Caliber III reads a temp of 69 degrees in the safe with a humidity of 27%. The Golden Rod measured the same temp but with a humidity of 42%. Both meters say that they have been calibrated at the factory and that no further calibration is necessary. Also that if standard humidity calibration tests are performed on either meter that it could ruin the meter's internal circuitry. Any thoughts? Any recommendations or suggestions? Thanks.
"Trust us, it's accurate. And if you don't trust us, and try to test it, you'll probably ruin it". I don't know about you, but that doesn't really fill me with confidence for either one. BTW, I'm surprised that a wireless anything could transmit a signal through a (presumably thick metal) safe. Does it really seem to be picking up a live signal? If you fiddle with the temperature or humidity in the safe (carefully refraining from calling it a "test"), does the reading change as expected?
Put them outside and compare them to the weather reports. BTW, I would not think it should take more than about 10 minutes to at least be very close to the humidity. Not sure what you have access to. but if you could lay your hands on a sling psychrometer, you could know absolutely from any where large enough to operate the psychrometer.
Ok, I reset both meters again. The GoldenRod was reset and within a few minutes, the numbers displayed and were the same as before. When the Caliber III reset, the temp displayed the same but the RH went from 39% to 78%. It may just be a faulty sensor. I have had it for a long time. Maybe low batteries too. Something I need to consider. Just noticed that EVA -dry has a similar model but it is a lot more than what I paid for the GoldenRod. Same set up though.
You could make your own wet bulb thermometer to get an accurate humidity and determine which gadget is correct.
Put both units outside and allow time to equilibrate , pull up www.wunderground.com for your area and click on wondermap, and then weather stations in right column. When you see them appear on the map click on the one closest to you and compare the results that show with your units. My humidity is currently 12 %, dry heat
I'm envious. American southwest? Back in 1962 I worked at a weather station just north of Yuma, AZ. We officially recorded a humidity of 1% one day. Now I'm just outside of Wash, DC. We're lucky if we can get below 50% humidity.
