Intrinsically safe portable alarm - has portable receiver that interacts with alarm transmitter and includes test signal facility

摘要

An alarm monitoring system includes a transmitter and a portable receiver with a built-in error signal detector. The alarm unit (1) consists of a transmitter that operates in conjunction with a periodic test signal that distinguishes between an alarm condition and any malfunction. Any correct alarm signal activates the portable unit. The portable receiver system (2) includes a fault input detector connected to an alarm display or sound unit.