Who Invented the Hygrometer?

Since most of us have watched the news from time to time, we're more than familiar with newscasters and meteorologists giving us a forecast on the weather. Half the time they may not get it right, but there is a foundation on which these predictions are made, and it has nothing to do with what it looks like outside. In all reality, they use a number of gadgets to calculate the weather. One such device is the hygrometer.

Identification

As with a number of inventions throughout history, the actual creation of the hygrometer is up for debate, as its development can be attributed to three different men. The first is said to have been crafted back in the 1400s by none other than Leonardo di Vinci. It was far more rudimentary in its construction than the more modern devices, but still seen as a "working" hygrometer. The second was built back in 1664 by Francesco Folli, a practitioner of medicine and one of the first researchers, so to speak, on blood transfusions. His model is believed to have found its way into very limited production and distributed exclusively to the "royals" of Europe. The third and probably most accurate device, making it more than likely the basis of today's hygrometer, was developed by Adolph Richard Assmann, a meteorologist and physician from Germany, in the mid-1800s.

Function

The basic function or purpose of the hygrometer is to measure the moisture in the air, or, to put it more plainly, the humidity of the air. The most simplistic and probably most renowned of the hygrometers is a device called the psychrometer, a mechanism that consists of two thermometers, one used to measure the "dry-bulb" temperature and the other to measure the "wet-bulb" temperature. The difference between the two readings is used to indicate the relative humidity.

Effects

While the creation of the hygrometer has allowed us to read the moisture of the air, including its dew-point, the actual measurement of humidity is of the more tricky dimensions of meteorology. The inherent problem with any of these devices, no matter what the complexity, is they're more apt to give a proper reading of relative humidity, or amount of water vapor in the air, as opposed to a conclusive amount of water currently present in the air, translating to variations from hygrometer to hygrometer. Does this mean that we are unable to get a proper read? Not really; it is difficult, but not impossible.

Types

Besides the psychrometer, there are other types of hygrometers that have been created and used to measure the amount of moisture in the air. The mechanical hygrometer used human hair that was connected to a needle to establish the amount of relative humidity. The idea was that the inherent nature of a substance like hair (its ability to expand and contract based on the environmental influence of moisture) would set the needle to move when there was a change in the amount of humidity in the air.

Features

Though hygrometers, at least the motorized variation, are generally used by meteorologists, they have also found their way into other areas. Museums will use hygrometers to measure the moisture in the air as a way to protect art and artifacts from being damaged or destroyed. Gyms use them to give a proper read on the heated moisture in their saunas. Tobacco shops use them to gauge the amount of moisture present to preserve cigars and other tobacco product in humidors.