Temperature and humidity sensors are among the most commonly used environmental sensors. Humidity sensors are also sometimes referred to as hygrometers. These devices are used to provide the actual humidity condition within the air at any given point or in any given place. Such devices are commonly used in situations in which air conditions may be extreme or where air conditions need to be controlled due to varying reasons.

Humidity is the presence of water within the air. The amount of water vapor that is present in the air can affect not only personal comfort but can also affect various manufacturing processes within industrial applications. For instance, in the semiconductor industry, moisture or humidity levels must be properly controlled and monitored to ensure proper wafer processing. Humidity control is also frequently important for incubators, respiratory equipment, sterilizers, and biological products. In addition, the presence of water vapor may also influence various other chemicals, biological, and physical processes.

Measuring humidity within the environment can be critical due to the fact that the higher the humidity, the warmer it may seem. In industries, humidity measurement is often important because it can affect the health and safety of personnel as well as the cost of the product. As a result, temperature and humidity sensors are often quite important.