Method and instrument for continuous monitoring of aerosols
US4140005A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 22, 1977 |
| Grant date | Feb 20, 1979 |
| Priority date | — |
| Expiry date | Mar 22, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A50/20
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and instrument for continuous monitoring of an aerosol as the sulfur content of atmospheric aerosols. The instrument has an electrostatic precipitator that is turned off and on at a given frequency to modulate the particle concentration of aerosol flowing through the precipitator. A total sulfur flame photometric detector sensitive to both gaseous and particulate sulfur receives a sample of the modulated aerosol from the precipitator. The modulated particle concentration of the aerosol supplied to the detector causes a fluctuating component in the detector output that is directly related to the sulfur particle concentration. This component is amplified by a frequency and phase sensitive lock-in amplifier tuned to the precipitator modulation frequency. The resulting output signal gives a continuous measure of the sulfur particle concentration entering the instrument.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.