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Measurement of soot particles with photothermal interferometry

The FHNW Institute for Sensors and Electronics is working on a new measurement method for detecting atmospheric soot particles.



Photothermal interferometry (PTI)


Development of a new measurement method for the sensitive, quantitative detection of atmospheric soot particles.

Starting situation

Atmospheric soot particles are mainly created by burning biomass and diesel fuel. Soot particles are known for their negative effect on our health. They also influence our climate because they absorb sunlight and thus heat up the atmosphere.


Our approach consists of measuring and examining the soot particles using so-called photothermal interferometry (PTI). In this process, soot particles are detected because of their very pronounced light absorption. The main difference to today's standard measurement methods is that the PTI method is very sensitive and hardly affected by measurement artefacts, as the measurement takes place in situ.


Project information


FHNW Institute for Sensors and Electronics


3 years


Schweizerischer Nationalfonds, EMPIR, Eurostars


Prof. Dr. Ernest Weingartner (Lead), Daniel Egli, Dr. Bradley Visser, André Meier, Peter Steigmeier