Vintage Thermohygrograph, Thermograph & Chart Recorder

Dated around 1970 - 90's

Serial number 18976

Manufactured by Casella - England

7 day wind-up mechanical movement

Working order

Good used condition for age, with some superficial wear, marks and discolouration. 

Thermohygrographs continuously record both the temperature and the relative humidity of the atmosphere against time by drawing a trace onto a chart. Thermohygrograph standard model is the more practical instrument and is slightly more accurate for temperature.