Abstract
The effects of thermometer shaft and of radiation on the wet bulb were investigated, and a new psychrometric formula for Assmann psychrometer was derived, that is, e=e"-Bp(t-t") where B=(6.60+0.011t")×10-4 above 0°C =5.8×10-4 below 0°C And it was remarked that the effect of the covering cloth of the wet bulb to the psychrometric constant B is not due to the sorts of the cloth, but is due to the mode of covering of the cloth.
