Gas analyzers
US4914720A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1988 |
| Grant date | Apr 3, 1990 |
| Priority date | — |
| Expiry date | Nov 21, 2008 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/097
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Gas analyzers of the non-dispersive infrared radiation type which are designed to measure the concentration of one gas in a mixture of gases containing that gas. An infrared radiation emitter is employed to emit energy at a frequency of 40-100 Hz with a system which includes a source driver and a timer; and a detector is used to intercept the attenuated beam after it has passed through the mixture being analyzed and output a signal indicative of the concentration of the selected gas. Also, a second detector is preferably provided so that a ratioed, error eliminating output signal can be supplied to the failsafe, signal processing circuitry of the analyzer. The detectors are electrically biased by way of flyback transformer based circuitry to improve the signal-to-noise ratio, and the signal processing circuitry can be adjusted to compensate for drift. The detectors are mounted on a thermally conductive substrate along with appropriate filters, a filter frame, and a cover. The signal processing circuitry and an analog-to-digital convertor supply information to a microcomputer which: turns the infrared radiation emitter on and off and controls a heater which keeps the infrared radiat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.