| 摘要 |
PURPOSE:To enhance the accuracy of a carbon dioxide concentration detection apparatus by improving the latching treatment of a reference value when the carbon dioxide concentration detection apparatus is calibrated. CONSTITUTION:The maximum value within a prescribed time (a) of signals from a carbon dioxide sensor 101 is stored in a maximum-output-value storage means (a) 102; the maximum value is stored in a maximum-output-value storage means (b) 1 only for a prescribed time (b). A group of maximum values which have been stored in the maximum-output-value storage means (b) 1 are weighted respectively by their dispersion; they are weighted by the difference from a reference value; the reference value is computed in a reference-value computation means 2. Thereby, the accuracy of the reference value is enhanced. In addition, when the maximum value is latched into the maximum-output-value storage means (a) 102, the stability of outputs is detected by using a sensor-output-stability detection means 6 so that the latching accuracy of the maximum value is enhanced. In addition, the state of a measuring atmosphere is known from the outputs of the sensor by using a sensor-output-value- dispersion monitoring means 7. Thereby, the proper maximum value is latched. In addition, the maximum value is monitored by means of dispersion degree and the reference value by using a maximum-value storage and monitoring means 8. Thereby, the reference value can be renewed stably. |
