The expression ‘spark detection system’ may be misleading; one could believe that sparks are the only cause of industrial fires and explosions.
A particle will emit light (spark), visible to the human eye when it has a temperature of about 1,300°F or more. All particles below this temperature are perceived by the human eye as ‘black’ particles.
The adjacent chart illustrates the temperature combustible material ignites. According to the National Fire Protection Association, NFPA, combustible material can ignite at much lower temperatures than 1,300°F. ‘Black body particles’ such as a mechanical impact may never emit light but can still generate enough energy to create ignition.