| 摘要 |
<p>PURPOSE:To restrain a temperature drift while reducing the number of times to enter an automatic zero correction sequence by short setting a time interval of automatic zero correction practiced in a measuring mode when the warming up time is short, and long setting the time interval of the automatic zero correction when the warming up time is long. CONSTITUTION:When an exhaust gas analyzer is put in a measuring mode condition, a sampling probe 11 is inserted in an exhaust pipe of an automobile, and exhaust gas is sampled. The sampled exhaust gas (sample gas SG) is introduced to a measuring cell 20 through a sample gas passage 10. Among infrared light passing through the measuring cell 20 by starting from an infrared light source 21, infrared light having a wave length proper to CO2, HC or CO contained in the sample gas SG introduced to the measuring cell 20 is absorbed, and a quantity of the infrared light incident on measuring detectors 23 to 25 is reduced. On the other hand, a quantity of the infrared light incident on a comparing detector 26 is not reduced because of a wave length having no absorbing band in the sample gas.</p> |
