United Scientific Supplies SPCRKIT-PK/15 Sling Psychrometer, Pack of 15

Features:

• Use this simple apparatus to measure relative humidity.
• Includes two plastic-backed Celsius thermometers, one for dry bulb measurements and the other for wet bulb measurements.
• The thermometers mount on a wooden handle so they can be spun to obtain temperature readings.
• Includes an activity guide with relative humidity calculation table.
• Requires assembly.