The most accurate way to measure Relative Humidity (RH%)!

Two 5˝” red spirirt filled thermometers are attached to metal back for whirling. To obtain a RH%, simply wet the wick of the wet bulb thermometer, whirl the psychrometer, and view both thermometer readings. Then, using the chart provided, determine the RH% (the optional slide rule makes this easier).

• Handle folds out of way when not in use.
• Supplied with humidity table, wick, & case.
• Range 20 to 110°F in 1°F divisions.
• Accuracy: ±1% scale.