Relative humidity and condensation measurement with a capacitive humidity sensor
US9360445B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 2011 |
| Grant date | Jun 7, 2016 |
| Priority date | — |
| Expiry date | Mar 10, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/121
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for measuring relative humidity including condensing environmental conditions using a circuit with a capacitive humidity sensor and a reference resistor each connected to an input of a switch device and thence a quadrature sampling circuit. A sinusoidal source is first connected to the reference resistor and secondly to the capacitive humidity while a signal ground is first connected to the capacitive humidity sensor and secondly to the reference resistor. This produces a first voltage and a second voltage that are each sampled in quadrature. A complex ratio of the sampled voltages is calculated and converted into a representation of relative humidity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.