Hygrometers: A History

We see our fair share of hygrometers here at our humidity calibration facility, but people didn’t always have the sophisticated devices that we have today. People have been measuring humidity for hundreds of years, and hygrometers have come a long way in that time!

Simpler Times

The first crude hygrometer was made in the 1400s by renowned inventor Leonardo da Vinci. Major leaps forward came during the 1600s; Francesco Folli invented a more practical version of the device, while Robert Hooke improved a number of meteorological devices including the hygrometer.

Historic hygrometer

Hooke’s version is noted as the first mechanical hygrometer as it measured the way in which an oat husk would change with the relative humidity. In the late 1700s, Horace Bénédict de Saussure built a hygrometer that worked in a similar fashion by measuring humidity with a human hair.

Modern Humidity Calibration

Today, many of the humidity devices that we calibrate fall into the category of psychrometers, which measure humidity using a pair of mercury thermometers. While one thermometer is dry, the other has a wetted base and is ventilated. The water causes the reading to drop as it interacts with heat, and the differing readings can be interpreted to discern the relative humidity of the environment.

Other types of modern hygrometers make use of lithium chloride or another semiconductive material. The resistance of such a materials is impacted by relative humidity, allowing users to find the latter by measuring the former.

Humidity instrument calibration

While these strides have certainly helped modern scientists to track relative humidity more accurately, it remains crucial for such precision instruments to be properly cared for and calibrated. At Atlantic Scale Company, we offer a convenient mail-in calibration service for hygrometers and other humidity-based instruments.

For more information on caring for your equipment and how we can help to ensure accuracy with your gear, be sure to contact us online or to call our team directly at (973) 661-7090 today!

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