370266 HAIR HYGROMETER (POLYMETER), WITH MERCURY THERMOMETER

This instrument, known as a polymeter, measures temperature, humidity, vapour tension and dew point. A mercury filled glass thermometer is attached. The humidity element is a bundle of human hair. The dial which indicates selective humidity is 80 mmø. Temperature range –20 to 50oC in 1o div. and Humidity scale 0 to 100 % 0.18 kgs in weight. 263 mm in length.