| 摘要 |
PURPOSE:To make it possible to perform highly accurate measurement, by controlling a current to a heating means so that the temperature of an electrochemical cell is kept stable based on the resistance value of the heating part of a heating element. CONSTITUTION:A solid state electrolyte 2 comprising stabilized zirconia, a similar spacer member 14 and heater plates 6 and 8 are laminated, and a unitary body is provided. An air path 10 is formed with the cut-out part in the member 4. A measuring electrode 12 and a reference electrode 14 are provided at the outside and the inside of the solid state electrolyte 2. A heating element 16 is provided between the heater plates 6 and 8, and a heater layer (heating means) is formed. The element 16 comprises a heating part 18 and current conducting lead parts 20a and 20b. The resistances RL and RL' from a detecting point 26 to the ends of the lead parts 20a, and 20b are made equal. Then, the resistance value RM at the central part of the heating part 18 is expressed by RM=(V1-V2)/A, where V1 and V2 are potential differences detected with potentiometers 30 and 32. When the voltage of a power source 22, which imparts a current value A, is controlled, RM becomes constant. Therefore, the temperature of the cell, which is heated with the element 16, becomes constant. |
