What Is a Hygrometer Instrument?
The hygrometer, along with many other instruments and scientific inventions, is used by meteorologists in their labs. It provides a clear measurement on humidity and has branched into multiple types of instruments. Some of the types of hygrometers have been around since the 1700s.
Other People Are Reading
-
Basics
-
The Hygrometer instrument is a tool that is used to measure the humidity of the air and/or the amount of invisible water vapor in a certain environment. Similar to how a thermometer measures temperature, the hygrometer measures the atmosphere's humidity. There are several types of hygrometers that are generally used by meteorologists for their studies.
Mechanical and Electrical
-
According to Britannica.com, there are mechanical and electrical hygrometers that are used in given situations. A mechanical hygrometer will "make use of the principle that organic substances contract and expand in response to the humidity." Substances such as goldbeater's skin and human hair are typically used. The electrical hygrometer will "measure the change in electrical resistance of a thin layer of lithium chloride (or of a semiconductor device) as the humidity changes.
-
Hair Hygrometer
-
The hair hygrometer will use hair under tension to measure the humidity in the area. When the humidity increases, the hair will simply become longer, as when the humidity declines, the hair becomes shorter. The hair is attached to levers on the instrument that magnify any changes in length. Then a hygrograph, which is operated by an ink pen and a rotating cylinder, will record what the humidity does during the day.
Dew-Point Hygrometers
-
The dew-point hygrometer is the most precise instrument that scientists use, and will usually have a polished metal mirror that is constantly cooled at a certain pressure and vapor content until the moisture begins to condense on it. The dew point is the temperature of the metal at which condensation starts.
History
-
When the dew point hygrometer was invented in 1751, it was said that the clear meaning of dew point meant to "measure humidity." The first basic way that it was used in the 1700s was with cold water. The cold water was added to water in a vessel until dew developed on the vessel. Then the temperature of the vessel (which was the dew point) gave a precise index of the humidity.
-
