| 摘要 |
PROBLEM TO BE SOLVED: To make a carbon dioxide gas measuring unit simple and compact by monitoring a signal value of the concn. of carbon dioxide detected by a detection means and correcting a signal base line value when the signal value is less than a corrected set concn. value during a definite period. SOLUTION: A detection means A1 containing a solid electrolyte type carbon dioxide gas sensor, a power supply necessary for driving the same, various temp. compensation circuits or signal amplifying circuits detects the concn. of carbon dioxide. A correction and calibration means A2 corrects a signal base line value when the signal value of the concn. of carbon dioxide gas detected for the definite period by the detection means A1 is not less than a corrected set concn. value. The definite period is pref. about one week or more and usually one - several months. The concn. data of carbon dioxide corrected and calibrated by the correction and calibration means A2 is inputted to the ventilation judging means B1 of a ventilation unit B and compared with separately determined required ventilation concn. and, if necessary, ventilation is started by a ventilation means B2. |
