A flame detector
is a detector that uses optical sensors
to detect flames
(UV) detectors work with wavelengths
shorter than 300 nm
. These detectors detect fires and explosions within 3–4 milliseconds due to the UV radiation emitted at the instant of their ignition. False alarms can be triggered by UV sources such as lightning
, arc welding
, and sunlight
(IR) flame detectors work within the infrared spectral band. Hot gases emit a specific spectral pattern in the infrared region, which can be sensed with a thermal imaging camera
(TIC) a type of thermographic camera
. False alarms can be caused by by other hot surfaces in the area.
UV and IR flame detectors compare the threshold signal in two ranges and their ratio to each other to confirm the fire signal and minimize false alarms.
IR/IR flame detection
Dual IR (IR/IR) flame detectors compare the threshold signal in two infrared ranges.
IR/IR/IR flame detection
Triple IR flame detectors compare three specific wavelength bands within the IR spectral region and their ratio to each other to reliably detect flames and minimize false alarms.
or a web camera
can be used for video detection (wavelength
between 0.4 and 0.7 µm). Like humans, the camera can be blinded by smoke
UV/IR flame detectors are used on hydrogen stations