Masons Hygrometer (B)

The Masons Hygrometer is housed in a yellow plastic case with lid and bulb protectors, the device has twin thermometers fitted over polished aluminium scale. A detachable water cistern is fitted to the lower case linking the “wet bulb” to the water cistern therefore providing both the “dry” and “wet” bulb readings. Hygrometric tables, a spare wick and full instruction are supplied making it possible to measure humidity and temperatures. The range is -5 to +50 degrees centigrade and 20 to 120 degrees Fahrenheit.