325 Hygrograph

Mechanism: Mechanical

The Fischer Hygrograph chart recorder can track humidity trends in real time.

The instrument is constructed of brass and finished in matt chromium plate. All axles are fitted with jewel bearings meaning the instrument has considerably low friction. The 325 Hygrograph uses the change of human hair or synthetic fibres depending on the moisture contained in the air to measure humidity. Fischer’s specialist treatment of the hair is the reason for the very low response time, even in the case of very low temperatures. For this reason, Fischer hair hygrographs are the preferred instrument for outdoor measurements.

Available as either the 325 Hygrograph with mechanical (wind-up) clock or 325Q with quartz clockwork. The latter of which can be changed in an instant between a daily, weekly or monthly revolution.

The 325Q is compatible with the Fischer 310 chart paper.


Models available: 325 / 325Q
Humidity range: 0-100% RH
Accuracy: +/- 3%
Electronic quartz clockwork with changeable revolution times:
Daily – 25.6h
Weekly – 176h
Monthly – 783h
Mechanical clockwork drum according to DIN 58658
Ships with:
60 charts for weekly revolution
2 x fibre tip pens
1 x Battery LR6

Data Sheets