DETECTALARM
ELECTRONIC AUDIO DETECTION SYSTEMS INDICATING AN ALARM CONDITION CONSISTING OF SOUND DETECTION MEANS, CANCELLATION SENSITIVITY CONTROLS, RESET CONTROLS, INPUT SENSORS, KEY SWITCH AND TIME CLOCK TAMPER SWITCHES, EMERGENCY BATTERY SOURCES, ALARM RELAYS, INPUT UNITS, AND PARTS THEREOF
Expired · May 25, 1967 · 72272337 ·