Calibration -- doing more than one???

[NavyChap]

I have four (4) D'Addario Humiditraks that I use in my cases. I am getting some weird readings and am thinking that perhaps they need calibration -- I have down loaded the "instructions" to calibrate -- but my question is,"Can I put all four hygrometers in the ziplock bag or do I have to do them individually?"

 Guitar sages, please respond!! I posted this in another forum, and after several days, and 75 reads, there have been no replies!  Thanks in advance -- Jim

[Edward]

Hi Jim,

Sure, you can do more than one in the bag.  What I recall reading in the past, however, is that the salt/bag process your reference calibrates at ~75%RH.  Problem is we want a gauge that is accurate in the 30-50% range.  No guarantee that hygrometer that is calibrated at 75% will read accurately at 47%. 

That said, this is geeky-detail stuff, and I'm personally of the mind that our guitars simply aint gonna swell up like grapefruits nor implode like a star if simple given reasonable care under any decent digital hygrometer.  So while I have no familiarity with the D'Addario Humiditrak, I'd simply advise one decent hygrometer, keep an occasional eye on it, and relax.  Guitars have somehow managed to survive for many a decade (let alone those Martys from the 1800s) without our uber-precision and care.

Edward

[NavyChap]

Thanks for the input Edward!!

[Edward]

You bet sir.