1 Humidity Sensor Manufacturers in 2022

What Is a Humidity Sensor?

Humidity sensor measure the humidity in the air, relative to the saturated water vapor content. They are sometimes used in combination with temperature sensors in the form of temperature and humidity sensor.

Humidity sensors are necessary measurement devices not only for home appliances such as air conditioners and dryers but also for machine maintenance and food processing. Some humidity sensor is small and connected to electronic circuits, while others are in probe form and can take measurements.

It is important to note that some methods are resistant to condensation, while others can be damaged by condensation. It is also necessary to understand the life expectancy of the humidity sensor.

The humidity sensor in a measurement device will gradually deteriorate as the sensor itself continues to be used for many years. And in general, the performance of humidity sensor usually deteriorates gradually over time.

The effect of this degradation is the deterioration of the measurement accuracy of the humidity sensor. In addition, degradation of the junction between the humidity sensor and the external output also occurs. Therefore, depending on the use environment and the type of sensor mounted, the life of the sensor is about 2 to 5 years.

Uses of Humidity Sensors

Humidity sensors are widely used not only in general household appliances but also in OA equipment, such as printers and in industrial applications. Examples of each application are as follows.

General Household Products

Humidity sensors are used in many products in the home. For example, they are used in air conditioners, refrigerators, automobiles, dryers, air purifiers, humidifiers, etc. Humidity sensors are indispensable for air conditioning products that regulate the human environment.

Office Automation Equipment

Humidity sensors are also used in printers and other office automation equipment. Office automation equipment does not like extreme dryness or humidity, so humidity sensors are used to measure the external environment and prevent equipment malfunctions.

Industrial Applications

Humidity sensors are also widely used in industrial applications. They play an important role in controlling humidity in food processing plants, plant cultivation facilities, semiconductors, and museum and art gallery storage areas. Humidity sensors are also used in medical equipment and in aerospace.

Storage Applications

Humidity control is also very important in the storage of exhibits in museums and art galleries. Therefore, humidity sensors play an important role in controlling humidity in storage areas.

Types of Humidity Sensors

With the development of polymer membranes for humidity detection, humidity sensors have become smaller and have improved in performance. There are two types of humidity sensors, resistive and capacitive, both of which use polymeric membranes, but each has its own characteristics.

Resistive Humidity Sensors

The resistive type of humidity sensors uses a polymer membrane stretched to fill the gaps between the electrodes inside the humidity sensors. When the polymer membrane absorbs moisture and water is absorbed, the ions in the membrane become mobile, and the resistance of the membrane changes.

The advantage of the resistive type is that it is inexpensive, durable, and suitable for areas with high humidity. However,  detection does not work well when humidity is low.

Capacitive Humidity Sensors

Capacitive humidity sensors are based on capacitor technology. It consists of an electrode that transmits moisture and a polymer membrane dielectric, such as cellulose or PVA, that absorbs moisture.

Since the capacitance changes depending on the moisture content of the polymer membrane dielectric, differences in moisture content can be detected as changes in capacitance. The advantage of capacitive humidity sensors is that they are more sensitive and have a faster response time than resistive sensors.

However, it should be noted that capacitive humidity sensors have the disadvantage of more complex circuitry.

Humidity Sensors in Smartphones

An increasing number of smartphones are equipped with temperature and humidity sensors. However, not all smartphones are equipped with a temperature and humidity sensors.

Therefore, to measure temperature and humidity with a smartphone, you need to download a free app or install an external sensor. Among those wireless sensors with smartphone integration, temperature and humidity sensors with Bluetooth functionality are available on the market.

The common name for these sensors is "environmental sensors." Environmental sensors have multiple sensor functions, such as temperature, illumination, air pressure, noise, etc., as well as humidity.

The measuring instrument that incorporates these superior sensor functions in a single module collects total environmental information. The area to be measured is diverse, ranging from ordinary homes to inside offices, outside offices, and inside manufacturing plants.