Infrared breath analyzer with calibration provisions and related method
US5422485A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 9, 1993 |
| Grant date | Jun 6, 1995 |
| Priority date | — |
| Expiry date | Jul 9, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/3174
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A calibration device, method and apparatus is provided for checking calibration of a breath alcohol measuring instrument. A silicon wafer with an anti-reflective silicon monoxide coating on both sides is used to attenuate the infrared radiation in the range of 3.35 to 3.80 microns wavelength in a manner to simulate the attenuation caused by a breath sample containing 0.10 BrAC. A comparison of the signal generated by the attenuation at a wavelength of approximately 3.48 microns is made to the baseline signal obtained before placing the calibration disk in the IR beam path and accurately simulates the breath sample. The related breath alcohol measuring method and apparatus provides for the positioning of the composite disk in the path between the infrared source and receiver. A computer compares the signals and performs the calibration check, as well as the actual BrAC analysis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.