| 摘要 |
<p>PURPOSE:To eliminate the drift by contamination and to make analysis with high accuracy by providing two pieces of sample cells, introducing a gaseous sample and reference gas alternately as specified time intervals to the cells, comparing the measurement data of IR absorbances and determining concns. CONSTITUTION:The gaseous sample of an introducing port (p) is introduced into the sample cell 2 and the reference gas of an introducing port (q) into the cell 2' when (a) and (b), (e) and (d) are connected by solenoid valves 8, 9. The valves 8, 9 are then changed over at the period T' larger than the rotating period T of an optical chopper 4 to connect (c) and (b), (f) and (e) to introduce the reference gas to the cell 2 and the gaseous sample to the cell 2'. Such operation is repeated at every period T' and the measurement data of the IR absorbances thereof are compared in a signal processing circuit 7', by which the concns. are determined. Since the gaseous sample and the reference gas are introduced at about the same degree into the cells 2, 2.. in such a manner, the cells are internally contaminated at about the same degree. The drift by the contamination is thereby eliminated and the analysis with the high accuracy is enabled.</p> |
