Convenient portable gauge for measuring relative humidity and dew point. Very important tool to determine when to stop irrigating during freezing conditions. This instrument compares the temperatures of a dry bulb thermometer and a wet bulb thermometer.

The psychrometer is spun around rapidly for a few minutes and readings are taken for the dry and wet bulb temperatures. After you have these readings, the back of the unit has a scale that allows you to correlate the readings. All psychrometer units come with a chart to help growers understand the relationship between dew point and temperature.