| 摘要 |
PURPOSE:To accurately measure the ultraviolet ray absorption of specimen gas in high temperature state by heating a light absorption cell at high temperature. CONSTITUTION:Cell heating heater 113 is wound on a light absorption cell 110. The gas temperature in the cell 110 is set at approx. 200 deg.C. under PID control of a temperature controller 114. A flue exhaust gas is continuously introduced into the cell 110. When ammonia gas is accordingly mixed with the exhaust gas, ammonia gas absorption spectrum is focused in the vicinity of an outlet slit 125. When the slit 125 is vibrated to wavelength-modulate it, the light reaching the light receiving surface of a photo electric multiplier 126 obtains light intensity modulation signal of the amplitude proportional to the ammonia gas concentration. A photo electric multiplier 126' provides a light intensity modulation signal of the amplitude proportional to the sulfur dioxide concentration. Thus, an output proportional to the ammonia gas concentration is obtained through a function generator 300 and subtracting circuit 400, and displayed on a display unit 500. |
