Capacitive humidity sensor with hysteresis compensation

Patent metadata

Field	Value
Publication number	US-9304098-B2
Application number	US-201314092410-A
Country	US
Kind code	B2
Filing date	Nov 27, 2013
Priority date	Feb 4, 2013
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A gas sensing device that includes differential temperature compensation.

First claim

I claim:

1. A humidity sensor comprising:
(a) a humidity sensitive element that estimates ambient humidity based upon a capacitive measurement to provide humidity data related to said ambient humidity;
(b) a trend adjustment structure that modifies said humidity data based upon a rate of a temporal trend of said humidity data.

2. The humidity sensor of claim 1 wherein said humidity sensitive element includes a hygroscopic dielectric material sandwiched between a pair of electrodes.

3. The humidity sensor of claim 2 wherein said humidity sensitive element includes a signal conditioning circuit.

4. The humidity sensor of claim 1 wherein said trend adjustment structure uses a difference based comparison.

5. The humidity sensor of claim 4 wherein said difference based comparison includes a difference amplifier.

6. The humidity sensor of claim 1 wherein said adjustment mechanism modifies said humidity data based upon a generally proportional rate of change of said humidity data.

7. The humidity sensor of claim 1 wherein said adjustment mechanism modifies said humidity data using a pair of filters each of which have a different time constant.

Assignees

• Veris Industries Llc

Inventors

• Pion Albert

Classifications

• G01N27/228

  Circuits therefor (measuring capacitance per se G01R27/26) · CPC title

• G01N27/225 Primary

  by using hygroscopic materials · CPC title