Alarm Set Point (signals and alarms)
Fixed or adjustable setting of the apparatus that is intended to preset the level of concentration at which the apparatus will automatically initiate an indication, alarm or other output function.
Source: IEC 60079-29-1, Explosive atmospheres – Part 29-1: Gas detectors – Performance requirements of detectors for flammable gases. Global Standards
Alarm setpoint is a fixed or adjustable setting at which the system will automatically indicate an alarm. The FSS Code, chapter 16, limits the maximum alarm setpoint to the equivalent of 30% of the lower flammable limit.
Source: IMO MSC.1/Circ.1370, Guidelines for the design, construction and testing of fixed hydrocarbon gas detection systems, 22 June 2010, International Maritime Organization. Regulatory Guidance