Mason’s Hygrometer

Easily measure humidity

• Instructions included
• Safe, does not contain mercury

One thermometer bulb is kept constantly wet by a siphon reservoir while the other gives a dry temperature reading. Humidity is obtained by comparing the two readings on the enclosed chart. The red liquid masons hygrometer uses a safe and easy to read red liquid in place of the usual mercury. Dual scales of -10/50°C and 10/120°F.