Temperature and humidity sensor for Cleanroom
Working Principle
● Temperature Measurement
Resistive: Utilizes the property of material resistance changing with temperature (e.g., thermistors, platinum resistance thermometers), calculating temperature by measuring the resistance value.
Thermocouple: Based on the Seebeck effect, the temperature difference between the junctions of two different metals generates a voltage, which is used to calculate temperature.
Digital Integrated: Employs a digital chip with a built-in temperature sensor (e.g., DHT11, SHT31), directly outputting a digital signal.
● Humidity Measurement
Resistive: Calculates humidity by observing the change in resistance of a humidity-sensitive material (e.g., polymer films) after it absorbs water vapor.
Capacitive: Calculates humidity by observing the change in capacitance of a humidity-sensitive material due to changes in its dielectric constant with humidity.
Digital Integrated: Integrates a humidity sensor chip (e.g., HIH-4000), directly outputting a digital signal.