Laser-Induced Incandescence

Soot is considered a hazardous pollutant emission, and is typically a result of incomplete combustion processes and is thus also related to combustion performance. Laser-Induced Incandescence (LII) is a laser-optical measurement technique dedicated to soot diagnostics. LII can provide measurements of soot volume fraction in e.g. Diesel engine exhaust and even instantaneous images of soot distribution during the formation inside a running IC engine.

Laser-Induced Incandescence (LII) Measurement SystemsThe view from below through the optical piston bowl of a Diesel engine (a), together with calibrated LII measurement providing instantaneous soot-volume-fraction images (b). Courtesy of H. Bladh et al, Lund University.


Non-intrusive, in-situ measurements Full control of hardware from the software
Multi-parameter measurements by combination with PIV or LIF Modular system allowing easy future upgrades

Detector Unit


Laser-Induced Incandescence (LII) Measurement Systems


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Learn more about LII for combustion diagnostics

Measurement Principles
A short, energetic laser pulse is used as illumination source for LII. The illuminated soot particles absorb the light and in this way they are heated up by the laser pulse to very high temperatures (~4000 K). Read More