Hi-Q Hygrothermograph

MEASURING TEMPERATURE: The Hi-Q Hygrothermograph employs an aged bimetal element to record temperature changes. The temperature pen arm covers a 3-1/8" area of the 7" high chart. The response is linear, with temperature recorded over a 110°F or 60°C span. Span is adjustable up or down to match the season (winter or summer).

MEASURING HUMIDITY: A specially treated bundle of human hair is used to measure relative humidity over the full range of 0% to 100%. The hair expands and contracts with increasing or decreasing amounts of water vapor in the air, which is also reflected on the recording chart. All internal parts are chrome-plated brass. Arm pivots are polished, instrument grade stainless steel for fast response. Charts and internal mechanisms can be viewed through the glass window at the front of the unit. Charts are installed on a self-contained brass battery operated clock. Gears adjust drum rotations to 176 hour or 31 day cycles.