One of the essential electronic equipment for numerous devices is a humidity sensor or RH sensor. There are numerous sensors present in the market but which is the best one for you? For an apt selection read this blog.
Humidity sensor has far and wide application in our day-to-day life. It is found in the HVAC system i.e. heating, ventilating and air conditioning. It is also present at the meteorology stations for weather predictions. Some other places include cars, industries, greenhouses, offices, etc.
It consists of the following layers within
Best humidity sensor may vary according to its application, but it is essential to check the following before making a purchase
- Cost-effectiveness etc.
How to check the working of a humidity sensor?
Voltage deviation is indicated by the linearity. The difference is measured between the BFSL value and the output voltage. This is converted to relative humidity.
Basis the 9 point system, every sensor has an individual calibration curve. This is used for the good and bad analysis of a particular sensor.
Reliability defines how trustworthy the measurements are as offered by the sensor. It is necessary to check the same as the sensor can anytime fall out of sync and display wrong measurements
It is the measurement of drift among other single quantity measurement. The values should not be poles apart.
Response time is the typical time required by a sensor to rise or fall. Generally the rise time is 66% and fall time is 33% of the output voltage.
There are three types of humidity sensors,
- Capacitive: It is used for measuring relative humidity. The two electrodes have a thin strip of metal oxide in between to measure the atmosphere’s relative humidity that changes its electrical capacity. The range may vary from 0% to 100%. It finds maximum usage in industries and weather applications with its low-temperature effect
- Resistive: It measures the electric impedance of atoms with the ions present in salts. On both sides of the salt medium, there is change in resistance of electrodes observed with the humidity change.
- Thermal conductivity: It is majorly used in areas with high temperatures. A difference between thermal conductivity of moist and dry air is calibrated for measurement of humidity. Even, dry nitrogen and ambient air is used for calibration.
How to take care of humidity sensor
For accurate results, it is imperative to take proper care of the humidity or RH sensor.
Check the environment: Use the RH sensor within the recommended temperature and humidity range for accuracy. A prolonged impact can affect the accuracy permanently.
Sensor Covering: It is necessary to store the sensor element or the humidity sensor in a protective case instead of keeping it exposed to outside air or harmful chemicals. This increases the durability of the instrument and offers a prolonged life.
Don’t touch the sensor element: Sensor elements being sensitive element needs to be handled with care. Unless imperative, don’t touch the sensor directly. Also, never wash the sensor or leave it in contact with compressed air/any other material.