Method and apparatus for in-situ measurement of soot by electron spin resonance (ESR) spectrometry
US8212563B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 2009 |
| Grant date | Jul 3, 2012 |
| Priority date | — |
| Expiry date | Sep 12, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/60
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An instrument and method using electron spin resonance spectrometry for measuring the concentration of airborne soot particles, and the like, that includes continuously passing a sample of exhaust gas through a resonating RF microwave cavity resonator during the application therethrough of a uniform slowly varying uniform magnetic field that is rapidly modulated and measuring the resulting phase modulation or amplitude modulation thereof to derive an electron spin resonance signal that directly senses the concentration of carbon free radicals produced as a result of inefficient combustion of hydrocarbons during operation of the vehicle or boiler. A further invention is the use of this signal for feedback control of the engine or boiler operating parameters to minimize or substantially eliminate particulate matter emissions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.