| 摘要 |
PURPOSE:To detect the presence of imperfect burning and of burning by means of a single detecting element, by a method wherein the presence of imperfect burn is detected from an electric conductivity, and the presence of burning is detected from the changing rate of the conductivity. CONSTITUTION:If imperfect burn occurs, an electric conductivity of an element 3 changes remarkably. The change is detected by an imperfect burn detecting circuit 11, and the closing of an electromagnetic valve 32 prevents the occurrence of imperfect burn. Immediately after firing, the temperature of the element 3 rises rapidly, and the conductivity also increases sharply. A comparing circuit 41 detects a changing rate of the conductivity immediately after firing to ascertain firing and actuate a relay 51. In case firing is not ascertained, when an operation of a delay circuit 16 is completed, the electromagnetic valve 32, simultaneously, is closed to prevent discharge of live gas. When firing is ascertained, a comparision potential of a comparator 42, simultaneously, changes, and the comparator 42 is used for ascertaining of an accident fire. Rapid decrease in the conductivity of the element 3 attendant upon the accident fire is detected by a comparing circuit 41 to prevent discharge of live gas. |
