G
PHYSICS
G
PHYSICS
G08
SIGNALLING
G08
SIGNALLING
G08B
SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
G08B
SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
G08B21/00
Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
G08B21/00
Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
G08B21/02
Alarms for ensuring the safety of persons
G08B21/02
Alarms for ensuring the safety of persons