What is a humidity sensor?
Humidity sensors can be defined as low-cost sensitive electronic devices used to measure air humidity. Humidity sensors are also known as hygrometers. Methods of measuring humidity include specific humidity, absolute humidity and relative humidity. The two main types of humidity sensors are divided into absolute humidity sensors and relative humidity sensors.
Based on the factors used to measure humidity, these sensors are further classified as thermal humidity sensors, resistive humidity sensors, and capacitive humidity sensors. Some of the parameters when considering these sensors are response time, accuracy, reliability, and linearity.
Working principle of humidity sensor
Humidity sensor is an important device that helps to measure the humidity of the surrounding environment. Typically, these sensors contain a component that senses humidity and a thermistor that measures temperature. For example, the sensing element of a capacitor sensor is a capacitor. In a relative humidity sensor that calculates the relative humidity value, the change in the permittivity of the dielectric material is measured.
The materials used to build resistance sensors have low resistivity. These resistive materials are placed on top of the two electrodes. When the resistivity value of this material changes, the change in humidity is measured. Conductive polymers, solid electrolytes, and salts are examples of resistive materials used to build resistance sensors. absolute humidity values, on the other hand, are measured by thermal conductivity sensors. Now let’s see how the humidity sensor works.
Application of humidity sensor
Capacitive relative humidity sensors are used to measure humidity in printers, HVAC systems, fax machines, automobiles, weather stations, refrigerators, food processing, and more. Due to their small size and low cost, resistive sensors are used in home, residential and industrial applications. Thermal conductivity sensors are commonly used in dryers, food dehydration, pharmaceutical plants, etc.
Our digital humidity and temperature sensor is based on a planner capacitance technology that integrates the humidity and temperature sensors in the sensing element. Using our extensive experience in reading small capacitance variations in accelerometers and gyroscopes, we developed a differential capacitance sensing element that, when combined with the temperature sensor, provides the relative humidity. It is easy to use with the sensor, signal processing circuitry, onboard calibration and proprietary algorithm intergrated in a single package.
The small size and low power consumption is ideal for use cases in consumer mobile, smart home(home appliances and HVAC), and storage and logistic applications.
Post time: Oct-07-2023