Dust sensor apparatus
US5910700A · kind A · utility
161Cited by
12References
16Claims
0Family size
Inventor
Key dates
| Filing date | Mar 20, 1998 |
| Grant date | Jun 8, 1999 |
| Priority date | — |
| Expiry date | Mar 20, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/0257
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A dust sensing apparatus uses a transducer element oscillating at a resonant frequency to detect changes in dust concentration. The transducer is fabricated from a polymer material which oscillates when a voltage is applied. The presence of dust affects the oscillation frequency. Dampening of the frequency by the dust presence changes the electrical resistance provided by the transducer. Electronic circuitry computes the level of dust by measuring and controlling the level of the AC signal required to maintain the oscillation frequency by monitoring the resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.