Looking for a motorized psychrometer

I used one of these in college and wondered if they still exist as I haven’t been able to find one. It worked well and was much easier on the wrist! Suggestions welcome!

Do you mean something like this - Casella Vintage Clockwork Aspirated Psychrometer Hygrometer | eBay

Something like that yes. The one we used at BSU was much smaller. Also, I found some new for hundreds of $$ but that is a little steep for my budget. I’ve seen the HVAC versions for as little as $25 but they are not fan aspirated and they do not use a wet wick so I really don’t trust them to be as accurate as their specs state.

The accuracy of mechanical (whirling or aspirated) psychrometers (+/- 2%) seems about the same as most electronic humidity sensors so is there any disadvantage in using an electronic sensor?

Possibly but here’s my concern with those and I welcome your input on this. That type seems to use a backward conversion to come up with the wet bulb temperature. I may be wrong but I was under the impression that an accurate wet bulb reading requires that the wet thermometer be “air cooled”. In other words, we need to have air passing over that thermometer or the reading may not be true. Thoughts?

There are aspirated electronic humidity sensors available which will likely give a better result than a sensor with little air flow past it.