| 摘要 |
<p>Method and sensor for infrared measurement of gas comprising one infrared radiation source which illuminates two detectors at different distances from the radiation source, a spectrally selective element for infrared radiation adapted to be absorbed in a gas .alpha. to be measured arranged between the IR source and each of the detectors, and another infrared radiation source that illuminates those same two detectors possibly via a spectrally selective element for infrared radiation which is not more than weakly absorbed by any present gas. The radiation sources are excited at different patterns in time, and an electronic unit is adapted to select and separately amplify the resulting signals at said patterns from the detectors and to use the mutual ratios between such signals to calculate the concentration of said gas .alpha..</p> |
