Humidity Sensor: Types, Characteristics, Advantages

by Sharon Martin Blogger and SEO Professional

A humidity sensor measures and reports both air temperature and moisture. The relative humidity is the ratio of moisture in the air to the highest amount of moisture at particular air temperature. When looking for comfort, relative humidity becomes an important factor. Humidity sensors work by detecting alterations that alter the temperature or electrical currents in the air. In all kinds of sensor, Humidity Sensor is one of the most important devices that have been widely used in consumer, industrial, biomedical, and environmental, etc. applications for monitoring and measuring Humidity. It may affect the business budget of the product and the health, safety of the personnel so Humidity measurement in industries is dangerous. Humidity sensing is very important for controlling systems for industrial processes and human comfort.

 

Types

Capacitive Humidity Sensors: Humidity Sensors made based on capacitive effect. Capacitive Humidity Sensors are one of the basic types of Humidity Sensors.

Advantages of Capacitive Humidity Sensors:

•The output voltage is linear.

•They provide stable results through long usage.

•They can detect a wide range of RH. 

Resistive Humidity Sensors: Resistive Humidity Sensors are another important type of Humidity Sensors that measure the electrical conductivity or resistance. The principle behind resistive humidity sensors is that the conductivity in non-metallic conductors is reliant on their water content.

Advantages of Resistive Humidity Sensors:

•Low costly

•Small in Size

•The distance between them signal circuit and the sensor can be large

•Highly exchangeable as there are no calibration standards.

 

Characteristics

•Accuracy is specified based on the specific standardization curves for any singular sensor.

•Hysteresis is the difference between the two voltages to %RH conversions at each of the four duplicated points in the nine-point categorization. In absolute %RH terms, hysteresis is recorded.

•Interchangeability describes the range of voltages for any population of sensors at this RH point. The output of the entire population of sensors will fall within this range when exposed to an RH of 0%.   

•Linearity indicates the voltage deviation from the measured output voltage value and the BFSL value, converted to RH.

•Reliability Sensors are subjected to faster stress tests. The sensor is considered a failed sensor if the test causes the sensor to drift and report RH outside recommended conditions.      

•Repeatability is the maximum variation of sensor outputs for repeated swings of humidity levels across the sensor’s measurement range under identical circumstances. 

 

Conclusion

Monitoring or controlling humidity is of supreme importance in many industrial and domestic applications. In the semiconductor industry, during wafer processing, humidity or moisture levels needs to be properly monitored and controlled. Humidity control in medical applications is required for biological products, incubators, sterilizers, pharmaceutical processing, and respiratory equipment. Humidity control necessary in food processing, dryers, ovens, paper and textile production, film desiccation, and chemical gas purification. Measurement of humidity in agriculture is important for plantation protection, soil moisture monitoring, etc. Humidity sensors are used to provide a signal of the moisture levels in the environment in all such applications and many others. 

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Created on Jun 23rd 2019 22:56. Viewed 409 times.

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