DETECTOR

摘要

PURPOSE:To always maintain a fixed level over all alarting areas by automatically adjusting the detection sensitivity according to the inclination of the alarting zone of a detector. CONSTITUTION:A detector 11 mounted on a ceiling surface 10 has a condenser mirror 16 supported rotatably with an arm 15 formed on the undersurface of a frame body 12 and a rotary switch 18. The condenser mirror 16 is rotated by turning a knob 25 to alter the inclination of an alerting zone to beta from alpha while the angle of rotation of the mirror 16 is detected with the rotary switch 18 and fed to a printed circuit board 26. As the alerting zone 2 is switched to 3 from 2, the zone dimensions change to B from A and according to this, the amplification factor of a processing circuit of the printed circuit board 26 or the reference voltage of a comparator are changed with the rotary switch 18 to ensure a fixed detection sensitivity.