Smoke detector with changeable pulse light emitting interval for monitoring purposes

摘要

A smoke detector comprising a light emitting section from which pulse light is radiated to a detection area with a predetermined period and a light receiving section which is disposed so as to be opposite to the light emitting section to receive the light for detecting a change caused in the detection area in the form of a change in photo-output level. The light receiving section has a monitor terminal for outputting a monitor signal corresponding to the photo-output level. When a measuring apparatus is externally connected to the monitor terminal, the supervision period is shortened as compared with the normal supervision period, so as to enable the monitor signal to be supervised substantially in real time, thereby facilitating an adjusting operation.