Humidity sensor with temperature compensation
A gas sensing device that includes humidity compensation.
1. A humidity sensor comprising:
(a) a humidity sensitive element within a housing that senses the humidity and provides a humidity estimate of said humidity to a microprocessor;
(b) a sensing circuit that senses power provided to electronic components of said humidity sensor, including a microprocessor of said sensing circuit, from a power source;
(c) an internal temperature sensor enclosed within said housing and provides an internal temperature signal to said microprocessor;
(d) said microprocessor modifying said humidity estimate based upon (1) said internal temperature signal, (2) a thermal resistance of said humidity sensor, and (3) said power including said power to said microprocessor.
2. The humidity sensor of claim 1 wherein said humidity sensitive element said provides said humidity estimate of said humidity based upon a capacitive measurement.
3. The humidity sensor of claim 1 wherein said humidity sensitive element said provides said humidity estimate of said humidity based upon a resistive measurement.
4. The humidity sensor of claim 1 wherein said housing enclosing said internal temperature sensor also encloses said sensing circuit, and said microprocessor.
5. The humidity sensor of claim 1 wherein said microprocessor is free from modifying said humidity estimate based upon a temperature sensor that senses ambient air temperature external to said housing enclosing said humidity sensitive element.
6. The humidity sensor of claim 1 wherein said thermal resistance is a constant.
7. The humidity sensor of claim 1 wherein said microprocessor said modifies said humidity estimate based upon a voltage provided to said electronic components.
8. The humidity sensor of claim 7 wherein said microprocessor said modifies said humidity estimate based upon a power provided to said electronic components.