Why it matters
It is faster than smoke detection because it does not wait for combustion products to travel to a sensor. For fast-developing fires that difference is the whole warning.
Sensing
Flame detection
Flame detection identifies the presence of fire directly by sensing the optical radiation a flame emits, rather than by detecting its smoke or heat.
How it works
Sensors respond to infrared or ultraviolet emission characteristic of combustion. Line of sight is required, and false triggers from sunlight or hot surfaces are the main design problem.
Example
A flame sensor positioned with a clear view of a welding bay detecting ignition of nearby material.
In Alfa HazardX
The flame channel is read both as a digital trigger and as an analog intensity. It is inverted: a brighter flame pulls the analog value down, so every threshold check on that channel is reversed.
Read further
Related terms
- Hazard detectionHazard detection is the act of determining that a hazardous condition exists now, usually by comparing a sensor reading against a defined limit.
- Threshold detectionThreshold detection classifies a reading by comparing it against one or more fixed limits, producing a discrete state such as safe, warning, danger or critical.
- Sensor fusionSensor fusion combines readings from multiple sensing channels into a single assessment, so that patterns spanning several channels become detectable.