Good hygrometers?

Zuzu

Arachnopeon
Joined
Mar 10, 2017
Messages
11
I'm trying to find an accurate hygrometer, which is proving to be difficult. Which one do you use/recommend? This will be for my mantis enclosures, so the smaller the better.
 

The Snark

Dumpster Fire of the Gods
Old Timer
Joined
Aug 8, 2005
Messages
8,314
Old but relevant: http://arachnoboards.com/threads/accuracy-of-hygrometers.29704/

On the accuracy aspect of cheap meters, they can be off by as much as 50%. This really doesn't matter. Simply make your own equivalency scale. X=..., Y=.... etc. Just be sure that you map the gradient curve since it may not be (probably isn't) linear. IE at one end it could be 20% indicated=20% while at the other 90%=65% indicated.
 

user 666

Arachnobaron
Joined
Jan 27, 2017
Messages
351
I read that thread, and I am surprised that no one has mentioned the salt trick.

You can calibrate a cheap humidity sensor by sealing it in a small container with a pinch of salt and a drop of water.

The trick is that if you leave it alone for a few hours, the salt will keep the RH at 75%.

If your humidity sensor says 65% then you know it's under by 10 points. If it says 80%, you're over by 5 points.

Note the discrepancy, and when you use the sensor just add or subtract as needed.
 

Ghost56

Arachnobaron
Joined
Aug 28, 2016
Messages
443
Buy one such as http://www.vegetronix.com/Products/VH400/
Make one like http://gardenbot.org/howTo/soilMoisture/
Or get a good multimeter and an appropriate moisture sensing probe. I used certified, calibrated Fluke meters at the hospital for just about everything from HVAC to IFM calibration.
I just skimmed through so I apologize if I missed it somewhere. Can the DYI ones be used above ground or just strictly in soil?

EDIT: Pretty sure it wouldn't work suspended in air, but I may be wrong.
 
Last edited:
Top