Conventional smoke detector barrier by reflection of infrered light beam with integrated test. Includes transmitter and receiver in the same unit and a reflector element. Easy line-up, the value of the received signal is indicated in two 7 segment displays. Incorporates dirt compensation, three state leds and a short-circuit isolator. Includes reflector (200 x 230 mm) for distances from 10 to 70 m, an additional complement being needed for longer distances (6500-LRK). Ideal for the protection of large industrial spaces and rooms with very high ceilings. Includes testing filters.