Measure and Record Ambient Temperature and Relative Humidity Simultaneously
For 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"H 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). For measuring Humidity, a specially treated bundle of human hair is used to measure relative humidity over the full range of 0–100%. The hair expands and contracts with increasing or decreasing amounts of water vapor in the air, which is also reflected on the recording chart. Two blue felt tip pens are provided. Red Felt-Tip Cartridge Pens are sold separately, –10° to 50°C, 7-Day Charts are sold separately in packages of 50, 10° to 120°F, 7-Day Charts are sold separately in packages of 50, and 10° to 120°F, 31-Day Charts are sold separately in packages of 25. Uses two AA batteries (sold separately).