| 摘要 |
PURPOSE:To eliminate the need to determine a reference characteristic curve for every measurement, by taking a measurement of exhaust gas by finding a temporary characteristic curve by distributing proportionally voltage-difference change values, corresponding to shifts in zero point and span point, to the reference characteristic curve. CONSTITUTION:Zero gas and span gas are flowed into analyzer 1, where zero-point shift value DELTAV0 and span shift value DELTAS are detected by differential amplifier 11, D/A converter 3, computer 4, etc. On the basis of difference value (DELTAS-DELTAV0) between those detection values, computer 4 counts proportional distribution value DELTAX of random CO concentration Cx due to shifts in the zero point and span point of the reference characteristic curve of concentration to an analyzer output voltage from equation I to set and memorize a temporary characteristic curve. Therefore, there is no need to find newly the reference characteristic curve at every time of a measurement due to shifts according to environment, and exhaust gas can be analyzed by measuring the density of CO, etc., easily and accurately without using reference gas unnecessarily. In the right equation, DELTAVs is (Vs'-Vs) and DELTAV0 is (V0'-V0) while Cs and Co represent CO concentrations of span gas and zero gas. |
