higròmetres

A hygrometer is an instrument used for measuring the amount of water vapor in the air, soil, or in confined spaces. This measurement is known as humidity. Hygrometers are essential in various fields, including meteorology, agriculture, industrial processes, and climate control within buildings.

There are several types of hygrometers, each utilizing different principles to determine humidity. Mechanical hygrometers often use materials that change in size or shape in response to humidity, such as hair or synthetic fibers. As the humidity increases, these materials expand, and this expansion is translated into a reading on a dial. Electronic hygrometers are more common today and typically employ sensors that change their electrical properties with humidity. Capacitive hygrometers measure changes in capacitance, while resistive hygrometers measure changes in electrical resistance.

Another type is the psychrometer, which consists of two thermometers: a dry-bulb thermometer and a wet-bulb thermometer. The wet-bulb thermometer has its bulb covered in a wet cloth. As water evaporates from the cloth, it cools the bulb. The difference in temperature between the dry-bulb and wet-bulb thermometers can be used to calculate the relative humidity. The accuracy and range of hygrometers vary depending on their design and intended application. Maintaining and calibrating hygrometers is important for ensuring accurate readings.