- Recorders type: Hygrograph
- Application: Agriculture, Building automation, climate measurements, industry, Museums, Research
- Norm: VDI 3786 Part 4 humidity
- Norm – WMO: WMO-No,8 7th Edition Part I Chapter 4 Measurement of humidity
- Manufacturer: Thies Clima
- Manufacture Year: 1987
- Operating conditions: Indoor, Indoor – Not in ammoniacal atmosphere, Outdoor, Outdoor – Not in ammoniacal atmosphere
- Measuring range [% RH]: 0 … 100%
- Measurement Accuracy: ± 2 % r. F. bei regelmäßiger Regeneration, ± 3 % r.F. (20…100%)
- Measurement methods: natural hair, synthetic hair
- Rotation of Time [h]: 1d – 7d, 1d – 7d – 31d, 14d / 31d
- Housing: Aluminum cast and stainless steel painted white
- Test certificate: +20 °C und 33%, 75%, 96%
- Dimension (cm): L:280 x 145 x 180 mm
- Weight (Kg): 2,0, 3,6
Description
A thermo-hygrograph or hygrothermograph is a chart recorder that measures and records both temperature and humidity (or dew point). Similar gadgets that record just a single parameter are a thermograph for temperature and hygrograph for humidity. Thermographs, where the fluctuations are recorded utilizing photography, were depicted by a few researchers as early as 1845, including Francis Ronalds who was Honorary Director of the Kew Observatory. An updated model of the initial machine was deployed across the public observational organization set up by the new UK Met Office in 1867 and facilitated by Kew Observatory. An alternative thermograph configuration has a pen that records temperature on a spinning cylinder. The pen is toward the end of a lever that is controlled by a bi-metal strip of temperature-sensitive metal which bend as the temperature changes.