Re: WiFi range ...

On Sun, 2 Aug 2026 11:59:29 -0400, Robert Komar wrote:

> Back when I was an student in the 80's, one mechanical engineering
> professor described doing wet/dry bulb measurements.  The thermometers
> were tied to lanyards, and you would whirl them around in the air at a
> certain rate to get more air flow over the bulbs during the measurement.
> It increased the difference between the wet and dry readings for better
> accuracy, and the tables were adjusted for that affect.  My old
> thermodynamics textbook has a Psychrometric Chart in the back that you
> could use for calculating the absolute humidity from the temperatures. 
> It doesn't say whether the bulbs should be whirled around or not, maybe
> that was common knowledge back then.

https://ktagage.com/product/sling-psychrometer/

The video shows the use of the charts. Barometric pressure comes into play 
too. I assume that takes into account elevation. The side by side types 
probably are good enough although with no motion the air around the wet 
bulb will be affected by the evaporation.

Digital hygrometers measure the capacitance or resistance of a moisture 
sensitive material. The common DHT11 uses resistance which isn't as 
accurate as capacitance but what do you want for $3? One of the Accurite 
pages mentions both methods but doesn't say which is used. In both cases 
onboard processing handles the raw measurements of the thermistor and 
humidity sensor 

I suppose I could build a 70 cm Yagi and go fox hunting to find the 
Accurite unit but whoever owns it probably wouldn't be happy with me 
taking it apart.