| 摘要 |
PROBLEM TO BE SOLVED: To precisely measure the concentration of carbon inside a furnace and to make the life of a sensor long by a method wherein the burnout air in a proper amount is blown on an external electrode and on a solid electrolyte by a burnout-air introduction pipe installed by particularly partitioning the inside of a sheath pipe and soot which is stuck is removed. SOLUTION: When the amount of carbon is measured by an O2 sensor 1, the reference air is introduced up to an internal electrode 6b from a reference- air introduction pipe 8, an in-furnace atmosphere gas which is introduced from a measuring-gas introduction port 12 is supplied directly to an external electrode 6a, and an electromotive force which is generated by the oxygen concentration difference of a solid electrolyte 2 generated across the electrodes 6a, 6b is taken out as a carbon amount signal. Then, after a lot treatment has been finished or at every definite time, the solenoid valve of an air supply unit is changed over, the burnout air in a definite amount is blown on the electrolyte 2 and on the electrode 6a via a burnout-air introduction pipe 11, soot (precipitated carbon) which is stuck to the electrolyte 2 and to the electrode 6a is burned, and an oxidized burning gas is discharged to the outside of the sensor 1 from the measuring-gas introduction port 12. |
