An audible alarm indicating that one or more sprinkler heads have been activated. "Flow" is often detected by a change in pressure, subjecting these systems to false alarms if anything affects the water pressure feeding the system, however transient
Wikipedia, The Free Encyclopedia, Glossary of firefighting equipment, Wikimedia Foundation, http://en.wikipedia.org/wiki/Glossary_of_firefight ing_equipment, CA, USA 2012. (Fr Srvc - Amer) {509}