A Vermont Dial Thermometer offers an attractive alternative to spirit thermometers. Though not quite as accurate as spirit tubes, dial thermometers offer an easy-to-read format. The hygrometer measures the moisture content of the air to determine the relative humidity. Our mechanical hygrometers take advantage of a time-tested method in which a synthetic fiber expands as it absorbs moisture from the air. This expansion, in turn, moves the metal coil to which it is bonded. As the coil twists, the pointer moves up the scale. As the fiber dries, the coil contracts and the pointer reverses direction. Relative humidity ranging from 45% to 70% is generally considered to be comfortable.
