Reading the previous thread about the hygrometer issue and the mention about how cheap they are, I looked one up on ebay and pulled the trigger for 15 bucks.  It was described as one of the smallest, came with a removal magent with sticky tape to attach to the lid of the humidor.  Has the RH, temp in C and F, and does something with measuring min and max humidity over time, although I don't really know how that works yet.  A really decent hygrometer.

So I throw it in my humidor and find out that my mechanical hygrometer is off by quite a bit - by about 9 degrees.  I'm doing the salt test now to make sure its really accurate.  A pretty big eye opener though.  For $15 probably a pretty good purchase.

-Paul

Can the digital one be calibrated?  I've heard that sometimes they are also off up to about 10%

I had a digital one awhile back along with my analog and when the battery ran out, I lost it somewhere.  The one I had you could not calibrate, but it was pretty accurate.

*P

Most of them you can't calibrate, and suppsoedly shouldn't need - part of the "value" of the digital.  However, if they are not calibrated/accurate from the factory then you have to account for any differences.  I havn't heard of them being that far off though.  10% sounds like a lot.  Most advertise +/- 2.  There are some out there now that you can calibrate.  I'm just basically using it as another poit of reference.  It definitely made me realize it was time to calibrate my analog one.

-Paul

I'm thinking of getting a calibratible digital, not sure if it's worth the extra expense though...

I got one a few months ago after comparing the one that came with the humidor to a friend's digital. Turns out the analog was 20% off. Sticks seemed to be fine though.

I have 2 digitals. One cost $20, the other $10. They differ by as much as 8% and even more on temperature. I have several analogs. Some are so inaccurate I don't use them at all. The rest vary up to 20%. If I put all my hygrometers in a 70% humidity humidor for a day, I'll get readings from 58-88%. I don't know how to calibrate any of them. I plan to keep 2 or 3 in each box eventually.

Quoteljlemer - 9/1/2007  1:01 AM

I have 2 digitals. One cost $20, the other $10. They differ by as much as 8% and even more on temperature. I have several analogs. Some are so inaccurate I don't use them at all. The rest vary up to 20%. If I put all my hygrometers in a 70% humidity humidor for a day, I'll get readings from 58-88%. I don't know how to calibrate any of them. I plan to keep 2 or 3 in each box eventually.

I keep 2 in my humidor.  A digital and an analog.  I've thought about getting a third since I know the  analog is off and just have to trust the digital works.

You should be able to adjust the analog ones by turning a screw in the center on the back.

-Paul