| 摘要 |
<p>An automatic calibration technique for a gas analyzer includes applying electrical energy to a source that is different from the level used to detect gas concentration in order to produce a different level of radiation from that used to detect gas concentration. The reduced level is applied with a non-absorbing gas in the gas sample chamber. The detector output at the reduced level is resolved to a calibration factor. The instrument can be linearized by repeating the calibration procedure at multiple different levels of reduced source radiation. In one embodiment, a source assembly (26) is provided that includes a plurality of infrared emitters (36) to which is applied modulated electrical energy in a timed sequence in order to produce output levels for three component gas concentrations. A filter (56) between each one of the sources (36) and a detector (50) pass radiation at an absorption line of one of the component gases.</p> |
