Salt Test Fail?

[eliu2010]

I tried doing the salt test with 2 different hygrometers, the analog one that came with my new humidor and a digital one I bought from Wal-mart. Both read 60% after 8 hrs in separate ziplock bags with damp (not wet) salt. Could both cheap hygrometers be off? Or is there something I'm doing wrong with my salt test? ...shouldn't they read 75%?

For the analog hygrometer's salt test, I put a teaspoon of salt in a bottle cap and dampened it with tap water (not distilled). I only put a few drops, enough to wet all of the salt, but not make it a soupy mix. After 8 hrs, the analog read 60%. Thinking my calibration was off by 15%, I decided to buy a cheap ($8) digital from Wal-mart.

Though some say digitals dont need calibrating, I noticed the digi was reading similarly to the analog, which, according to the salt test, is off by 15% . I tried a salt test for the digital, and after 8 hrs, it too read 60%. Are both of them off?

Thanks.