08/12/2026
Artwork requires a lot of special care, from how its unpacked, stored, installed, repacked, transported and everything in between. One way JNAAG works towards collection conservation is with the actual environment the art is stored in, and the mechanisms used to maintain the perfect conditions.
Before the gallery moved into its current location, which has an advanced building automation system, gallery staff used a drum hygrothermograph to record relative humidity and temperature.
Swiss physicist and geologist, Horace Bénédict de Saussure, refined the drum hygrothermograph design in 1783 to use stretched human hair as its sensor. Human hair was used because its hygroscopic (able to absorb moisture from the air) and its length changes with humidity.
The apparatus works by the human hair shortening or lengthening depending on the humidity, which moves a lever that charts the levels on a rotating drum.
Relative Humidity (RH) and temperature are critical for art galleries because fluctuations in either can cause irreversible, physical damage to artwork.
Some art galleries continue to use drum hygrothermographs today, but here at JNAAG we have fully transitioned to digital hygrothermographs, which capture and record humidity in a software program called a Building Automation System.
You can read more hygrothermographs on the AGO - Art Gallery of Ontario website: https://loom.ly/RY7jPqs
