A hygrograph is a meteorological measuring instrument for detecting and recording air humidity over a continuous, temporal course. It is therefore a recording hygrometer that controls a recording arm based on its specific input measurement method. This, in turn, has a writing tip at its tip, with which it transfers the air humidity or the corresponding humidity measurement onto a rotating paper drum, thus graphically displaying it. Hair hygrometers are the most commonly used input measurement method and display the relative humidity. The recording period is determined by the rotation speed of the paper drum.
The main features of the hygrograph with display are:
- Can also be used below 0 °C
- When the relative humidity fluctuates, the natural hair regenerates itself
- low hysteresis
- high reaction speed
- good handling
- high reliability
- easy operation
- mechanical and electronic clockwork