| 摘要 |
PURPOSE:To obtain a good transient characteristic by eliminating overshoot, by placing no transition metal oxide inside the projection part of a gas diffusion port in the opening direction thereof. CONSTITUTION:The negative side of a differential amplifier 15 is held to reference voltage Vc and a resistor R1 is provided to transition metal oxide 6 in series and constant voltage V1 is applied to obtain output voltage V2 divided by the resistance value of oxide 6 and the resistance value of the resistor R1. This output voltage V2 is inputted to the positive side of the amplifier 15 and the amplifier 15 supplies a pump current Ip to an oxygen pump cell 14 so that the output voltage V2 becomes equal to the voltage Vc. The reduction in the value of the current Ip in a rich side is attained with respect to the change in the air excessive ratio of gas to be measured. The shape of oxide 6 is changed and oxide 6 is not placed inside the projection part 11a of a gas diffusion port 11 in the opening direction thereof. By this method, because the replacement of the gas is a gas diffusion control space 9 is performed by a minute quantity of a current, no overshoot appears. |
