Microwave detection of soot content in a particulate trap
US4477771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 21, 1982 |
| Grant date | Oct 16, 1984 |
| Priority date | — |
| Expiry date | Jun 21, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/40
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Conductive particulates in the form of soot are collected from diesel engine exhaust gases on a porous wall monolithic ceramic filter in such a way that the soot is somewhat uniformly distributed throughout the filter. The filter is housed in a chamber having a property of a microwave resonant cavity and the cavity is excited with microwave energy. As the particulates are collected the cavity appears to the microwaves to have an increasing dielectric constant even though the matter being accumulated is conductive rather than dielectric so that as collected on the porous filter it has the property of an artificial dielectric. The response of the cavity to the microwave energy is monitored to sense the effect of the dielectric constant of the material within the cavity to provide a measure of the soot content in the filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.