| 摘要 |
PURPOSE: To stably measure the concn. of oxygen over a long period of time by applying monitor voltage across electrodes arranged so as to hold an oxygen ion conductor therebetween. CONSTITUTION: When a power supply is closed, a microprocessing unit(MPU) is operated and a switch Sb becomes a closed state and a signal 'on' is taken in the MPU through an input board 3ic. At the same time, a sensor 1 stands by until a temp. rise is started by the heater 1b connected to a heating power supply 8. After a temp. rise completion time T1, the state of a switch Sa is investigated through an input board 3ib and, when the signal 'on' is inputted, the sensor becomes a continuous measuring state. In such a case that a signal 'off' is inputted to the input board 31b, the sensor becomes an intermittent state. A timer 11 is operated and monitor voltage is applied to the detection part 1b of the sensor 1 by a relay R and a power supply 2 and a limit current is continuously measured to calculate the canon. of oxygen. |
