Bought a new Xikar digital hygrometer (PuroTemp Rectangular 833XI) which doesn't have a calibration button - supposed to be ready out of the box.  Still I decided to do the salt test to check it and it would not go above 68% after 36 hrs. in the bag.  I wrote a note to Xikar and they directed me to a video ( https://www.youtube.com/watch?v=zkw4fTNoL90 ) for performing a salt test "the right way".  They recommend using a small sealed container like a small tupperware, not a zip-lock bag as I had been doing.  It read 76%.  So I rechecked my other 2 recently recalibrated round digital hyrometers and sure enough they were high when using the sealed container.

 

 

Good tip, thanks!

Good Video.  I have always done the ziplock bag test.  Makes me want to take all my hygrometers out and do a double check.

I used to do the zipploc but a couple years back I stole one of the wifes containers to do it and havn't gone back since.

cool video but I ain't goin for the BS about taking the calibration out bcs we fluck it up more often than we get it right. they are just cheaper to make I bet.
I use the Bovida bag and it matches my what my Fluke 971 reads which has never matched what the new Zikar reads.

Good video.  Thanks for posting that.

Great video! thanks for sharing.

Thanks for the link I'm retesting my hygrometers in a small sealed container 

I could be wrong but buying a hygrometer @ $20 or so you are not going to get a precise instrument. I have been using a Western Digital that is not adjustible for 5 years and I know if it is @ 65 or 66 % it is my sweet spot. Now is it actually @ that RH?  Yea I expect it is off 1 or 2 %.

Thanks for sharing.