Opacity meter for monitoring exhaust emissions from non-stationary sources
US6025920A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 6, 1996 |
| Grant date | Feb 15, 2000 |
| Priority date | — |
| Expiry date | May 6, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/534
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Method and apparatus for determining the opacity of exhaust plumes from moving emissions sources. In operation, a light source is activated at a time prior to the arrival of a diesel locomotive at a measurement point, by means of a track trigger switch or the Automatic Equipment Identification system, such that the opacity measurement is synchronized with the passage of an exhaust plume past the measurement point. A beam of light from the light source passes through the exhaust plume of the locomotive and is detected by a suitable detector, preferably a high-rate photodiode. The light beam is well-collimated and is preferably monochromatic, permitting the use of a narrowband pass filter to discriminate against background light. In order to span a double railroad track and provide a beam which is substantially stronger than background, the light source, preferably a diode laser, must provide a locally intense beam. A high intensity light source is also desirable in order to increase accuracy at the high sampling rates required. Also included is a computer control system useful for data acquisition, manipulation, storage and transmission of opacity data and the identification of the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.