I was shying away from the $20+ ones, I have 2 of those and both are crap, I did the salt test many times and they both read different #'s each time I did it, a battery change didn't help either and these aren't adjustable.
Which ones do you have?
I am not a huge fan of the salt test, you can get different values depending on how much water you add to the salt and how long you leave them in the bag/container.
Although it does cost a little money and it pretty ghetto, the boveda calibration kit does what it is suppose to do. Actually, if you have any boveda packets laying around, any of them can be used to calibrate a digital hygrometer. Just leave them sealed for at least 24 hours, 8 hours really is not enough.
Like I have said before, I own nine Western Digital Caliber III's. About a month ago I decided to calibrate them all, I wanted to know for sure how accurate each one was. So I changed all the batteries and over a period of 4-5 days calibrated each of them.
I have the actually data at home, but off the top of my head: 4 were +1, 2 were perfect, and 3 were -1. All were within the +/- 1 error as described from the manufacturer.
Now, maybe I have gotten lucky and have gotten nine good ones, who knows.
I have bought several of them from Mark at Cigarmony, who seems to run out of them at lot faster than the adjustable ones. Which I like to think means something other than just that he has less of them in stock.
:r
I also wonder about the adjustable digital hygrometers, does anyone know if they need to be re-adjusted when you change the battery?
