Thermohygrometers

A thermohygrometer is a precision instrument, approved by the World Meteorological Organization and that records the temperature and humidity values on a daily basis in graphical format.

The thermometer works through a spiral system by dilation and contraction of the same, while the hygrometer is also based on the contraction and dilation of hair of natural origin.
The equipment is completed with a drum where the recording graph paper goes and a stylus with a marker that transmits the movement to the paper and writes on it.
There are several models, depending on the range of temperature and humidity that can be registered.