The Hygrometer
The hygrometer is a device used to measure humidity the water and moisture in the air. Hygrometers measure humidity in percents from zero precent to one hundred percent, one hundred being dense fog or mist.
A History of the Hygrometer
The first hygrometer was invented by Leonardo Da Vinci in the 1400s. Da Vinci was far ahead of his time and invented many things that we use today. Ferdinand II, the grand duke of Tuscany invented the condensation hygrometer in 1650. In 1664 however Francesco Folli of Italy reinvented the hygrometer making it more practical and easy to use. 1783 was when Swiss H.B. Saussure discovered that human hair could measure humidity and invented the first hair hygrometer. French Leslie discovered another way to measure humidity by using a dry and wet bulb thermometer. French H.V. Regnault created the dew point thermometer in 1854.
The Many Types of Hygrometers
Over the years many types of hygrometers have been developed to do the same job. These hygrometers are the condensation hygrometer, the dew point hygrometer, the hair hygrometer, and the dry and wet bulb thermometer. Lets start with the hair hygrometer, the hair hygrometer works because with the more humidity in the air the more the hair curls. So scientists have been able to match the amount the hair curls to a exact precent of humidity. Secondly let me explain the dew point hygrometer, the dew point hygrometer has a exposed bulb. This bulb lets in air and then measures the amount of water vapor in the air. Now lets talk about the condensation hygrometer, the condensation hygrometer measures humidity by creating a stabilized condensation and the temperature at when this happens is measured and shows humidity. Next I will talk about the dry and wet bulb thermometer. Despite the fact that it's a thermometer the dry and wet bulb thermometer measures humidity, it does this by water that evaporates from the thermometer and gathers on a cloth at the top, the temperature is then recorded which can be translated into humidity. All of these are different hygrometers with different ways to do the same job, and record humidity.
Why do we measure humidity?
Humidity is measured so that we can learn important details about weather and climate. Humidity tells us if a certain place is usually dry or wet and or if it's higher than average or lower. Humidity can also tell us if it is dangerous to keep objects like books or paper there, because the humidity will curl them and cause large amounts of damage. The humidity can also tell things about weather like if it will rain, because rain happens when large amounts of water vapor form into clouds and the overflowing water falls back down. So if there is lots of humidity there is a larger chance it will rain because of all the moisture. Humidity can tell us if there is not enough water in a place. Humidity can also tell us if water is near by or not, because if there is water near by more water vapor will evaporate from it and it will be more humid. So all in all humidity can tell us a lot of things whether they are related to weather or not.
Bibliography
Condensation principle hygrometer http://www.npl.co.uk/publications/good-practice-online-modules/humidity/hygrometers/condensation-principle- hygrometer/
A Brief History of Humidity Measurement http://www.cwb.gov.tw/V7e/knowledge/encyclopedia/in008.htm
Temperature Measuring the Weather. Published by Heinemann Library. Chicago Illinois. 2007.
"History of Weather Observing Tools" https://www.weathershack.com/static/ed-history-of-weather-observing-tools.html
"Hygrometers" http://physics.kenyon.edu/EarlyApparatus/Thermodynamics/Hygrometer/Hygrometer.html
"What is a Hygrometer? - Definition & Uses" http://study.com/academy/lesson/what-is-a-hygrometer-definition-uses.html
A Brief History of Humidity Measurement http://www.cwb.gov.tw/V7e/knowledge/encyclopedia/in008.htm
Temperature Measuring the Weather. Published by Heinemann Library. Chicago Illinois. 2007.
"History of Weather Observing Tools" https://www.weathershack.com/static/ed-history-of-weather-observing-tools.html
"Hygrometers" http://physics.kenyon.edu/EarlyApparatus/Thermodynamics/Hygrometer/Hygrometer.html
"What is a Hygrometer? - Definition & Uses" http://study.com/academy/lesson/what-is-a-hygrometer-definition-uses.html