MONOLARM
ELECTRICAL SUPERVISORY ALARM SIGNALLING APPARATUS WHICH CONSISTS OF AN ENCLOSURE CONTAINING SEVERAL RELAYS, SIGNAL LIGHTS, AND ASSOCIATED WIRING FOR AUTOMATICALLY SUPERVISING INDUSTRIAL-CHEMICAL PROCESSES CAUSING AN AUDIBLE AND VISIBLE ALARM TO BE REGISTERED WHENEVER THE SUPERVISED CONDITION DEPARTS FROM THE NORMAL
Expired · January 28, 1952 · 71624208 ·