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The other day I posted about my pringled top and humidity in my shop. So yesterday, I popped over to Dave Collin's shop to check out my new (to me) sling psychrometer which was reading about 10 points higher than my caliber III. He pulled out 4 psychrometers and we had the, mine and my caliber all going at the same time.

So, 3 out of the 4 psychrometers plus the caliber all agreed within 2% of each other. My psychrometer was reading....10 points high. Looking at the wick, it was dirty and I had used tap water, not DW to wet it. The dry bulb readings on all of them matched, it was that my wet bulb wasn't going down as far as the others.

The psychrometer I have is a Bacharach and it has a very long wick so I cut off the dirty part and soaked the rest of it in DW for several hours stirring from time to time. I pulled it and dried it over night. I then washed my hands and re-installed the wick. Moistened with DW and ran it in the basement using my dust collector to draw air over the bulbs.

Compared to my caliber that read spot on yesterday, the psychrometer is still reading about 10 points high!?!

I can buy a new wick but they only come in 4 packs for $20 which seems kind of crazy. Questions are:

Any other ideas as to why my wet bulb isn't dropping in temperature right?

Anyone want to buy a couple of Bacharach sling psychrometer wicks off me?

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It's possible the thermometer used for the wet bulb may be inaccurate. Remove the wick and let it dry and stabilize then see if it reads the same as the dry bulb thermometer. If not, you may need to replace that thermometer (maybe it's under warranty?).

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Formerly known as Adaboy.......