| 摘要 |
PURPOSE:To make it possible to prevent the erroneous operation of a control system, by providing a means for stopping control operation when the correspondence of the output signal of an oxygen concn. detector and the oxygen concn. in gas to be detected is broken. CONSTITUTION:When a current I is flowed to an electrolyte 1 by a current controller 2, voltage V is obtained in a voltage detector 3. Oxygen partial pressures inside and outside a chamber 5 are respectively set to PV, PA. When the partial pressure outside a diffusion resistance body 6 is set to PM while coefficient D of diffusion is made constant and the current I is increased, the partial pressure PV in the chamber is lowered and the voltage V is increased. At this time, voltage V' is compared with a set value V0 by a comparator 10 while a current I0 obtained when the current I is controlled so as to equalize V, V0 by a current setting device 11 is detected by a current detector 4 and inputted to an operation treatment circuit 9 to enable the detection of the partial pressure PM corresponding to the oxygen concn. in gas to be measured. |
