What is a good way to calibrate a hygromitor that is built into a humidor?

Don’t.

Get an electronic one for inside.

Or get beads and quit worrying

+1
Or Bovedas and fuhgetaboutit....
Actually, Bovedas and beads together is a great combo I’ve been running for many years.

i can’t post for 25 seconds.

How DARE you!

I quit looking at the gauges when I went to Bovedas and Heartfelt beads.

Beads all white / Bovedas shrinking = time to rehydrate the beads. After a week the beads will be half and half and the Bovedas fluffy.

It's been pretty foolproof for me after several years. I'm only managing one small humidor at this point but the process was the same while juggling several big cases.

^ so you’re low??

That’s how I took it

assuming the built-in is analog, it may be worthless after a year anyway

I have an analog in a tabletop humi that's dead on...…...and almost as old as Frank.I use an electronic in it anyway,more trustworthy and easy to salt test.

You are the last cat that should be stoking that fire. [frypan]

I am trying to honor our deal, this is making it tough Mr. "No Lanceros"

🌫

HeartFelt beads and a digital. "Trust, but verify!"

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Super-absorbent polymer spheres/chunks with 50/50 and Bovedas for two-way "trimming".

Works excellently, and you never do anything to maintain the Bovedas, they self-maintain. All you do is refill the containers of the polymer spheres/chunks with distilled water or occasionally fresh 50/50.

Oh, and Western/Oasis Caliber IV units, very carefully and accurately calibrated.

No HF beads. Not paying some guy $65 (or whatever it is) for a certain kind of sand he probably got for 10 cents as part of a giant bulk order from his sooper seekrit supplier. I have my own retirement to worry about, I ain't gonna fund his!
.

I do the bead/boveda combo also. Still watch all the meters but don't sweat it as much as I used to. I also have a couple analogs that I've never had an issue with, but electronic also because I heard so much about the analogs.

I have an old Fench analog that’s been nuts for almost 10 years...........actually 3% “over”............but always 3% over on salt test.

I do like Dan does, but instead of rehydrating beads, I just swap out the Bovedas..........no spraying or pouring water on beads, etc.

Then those Bovedas get recharged in my special, patented, top of the line “rehydration chamber”.....................Send me $20 for directions on how to make one.....

You can't go wrong with a Boveda Butler BlueTooth RH and TEMP sensor. They go for around 20 bucks or less online and use a free iOS or Android companion app to see the gauges.

I tested out all of the higher rated digital HGs out there using my $400.00 scientific grade hygrometer as reference. (I run the NOAA weather station for our rural town and the scientific grade HG is part of the weather station's arsenal of hardware).

Anyway... After calibrating the top three sensors I tested, the Boveda Butler was the clear winner 2 months later when I retested the same three sensors for drift and their 2 month average. As a result of my testing, I now run a Boveda Butler in all (4) of my cabinets. Impressive little bugger, especially considering the ridiculous retail price Boveda is giving these things away for. I would pay 3 times the price for one of these if I had to!

OK, I'm looking for the $20 version. They all look to be $40 now a days.

Replace it. U can one on here that can be calibrated for around $10 if you're patient. Use a boveda in a ziploc or salt test to calibrate.

I saw this one drop to 10.93
https://www.cigarbid.com/a/hygro-set-adjustable-digital-hygrometer/3409561/ 

I've got good digitals that are calibrated. But for $20 I would have tried a bluetooth version for my winador in the basement. $40 not so much.

But, it's probably better to check it every so often anyway. 🤔