| 摘要 |
PURPOSE:To enable to obtain reliable action by improving a special character of a oxygen starvation sensor, by appling at least two pieces of elements (oxygen starvation sensor) resistance values of which are varied according to density of either oxygen or carbon monoxide. CONSTITUTION:In a control circuit consisting of lack of oxygen sensors 1 and 14, although an output of an amplifier 17 is low as electric potential at a point (c) is far lower than that at a point (d) when oxygen density, for example, is more than 20%, resistance values of lack of oxygen sensors 1 and 14 are started to reduce when the oxygen density is reduced gradually by closing a room. Then, electric potential at a point (e) of an amplifier becomes high at the time when the electric potential at the point (c) becomes slightly higher than that at the point (d), an alarm circuit 12 is actuated and an alarm lamp 21 is lit intermittently. With this, safety action for lack of oxygen is made to perform stably as sensitivity for the lack of oxygen is improved and, moreover, dispersion of special characters of detecting element for lack of oxygen can be absorbed. |
