Description

Sper Scientific Ltd Masons Hygrometer obtains humidity by comparing the 2 readings on the enclosed chart where one thermometer bulb is kept constantly wet by a siphon reservoir while the other gives a dry temperature reading. It features dual scales of 10 deg. C to 50 deg. C and 10 deg. F to 120 deg. F. Uses a safe and easy-to-read red liquid in place of mercury. Dimensions: 12 x 2 1/8 x 1 1/4 inches.