A Psychrometer is a hydrometer that uses the difference in readings between two thermometers. The first thermometer utilizes a wet bulb ventilated to cause evaporation and the other has a dry bulb to measure atmospheric moisture. The L7241 and L7242 sling psychrometer has two 9-1/2" mercury filled thermometers mounted on a stainless back and a swivel type handle. Also furnished is a wick and humidity tables. The L7245 and L7246 pocket sling psychrometer has two 5-1/2' mercury filled lens front thermometers attached to a metal back with a handle for whirling. Supplied with humidity tables, wick, and a pocket case.
