Psychrometric Slide Rule

Quickly Calculate Relative Humidity

This easy-to-use, flexible white plastic slide rule quickly calculates the percent of relative humidity by comparing wet and dry bulb thermometer temperatures.
Specifications: Temperatures are listed in Fahrenheit from 20°–100°F with relative humidity marks from 10–100%. The rule measures 6-3/4" x 7/8" and can be used with any sling type psychrometers.