Dual channel nitrogen oxides analyzer
US3967933A · kind A · utility
35Cited by
11References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 23, 1974 |
| Grant date | Jul 6, 1976 |
| Priority date | — |
| Expiry date | May 23, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T436/179228
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Sample air is divided into two paths. One path leads through a thermal converter where ambient NO.sub.2 is changed into NO. The other path passes through equivalent tubing to keep the air samples synchronized. Both samples then go to separate cells where each combines with ozone. The resulting chemical reaction produces light, chemiluminescence, which is measured by separate photo-multiplier tubes. Electronic circuits translate the results into simultaneous readings of NO.sub.x and NO concentrations. A difference amplifier subtracts the NO from the NO.sub.x to give a continuous NO.sub.2 value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.