| 摘要 |
PURPOSE:To control a solid electrolyte to keep it to a constant temperature, to simplify the structure of a detecting part, and to execute the measurement stably, by controlling so as to keep the resistance of a heater for heating the solid electrolyte to a constant value. CONSTITUTION:A transducer 20 supplied electric power to a heater 9, also a controlling circuit 23 detects resistance of the heater 9 so as to reduce a resistance value to a setting value, and controls the electric power to the heater 9, through an element 24. Subsequently, when a solid electrolyte 1 is set to a constant temperature, air is fed into the surface of its inside through a reference gas leading-in pipe 8, contacts with a porous electrode 3, and simultaneously, combustion exhaust gas which has passed through a leading-in port 14 of gas to be measured, and a filter 12 is led in through a porous electrode 2, to contact with the outside surface of the electrolyte 1. As a result, voltage generated between the electrodes 2, 3 is applied to an indicator 22 after it has been amplified, and oxygen density of the gas to be measured is indicated. |
