Laser Diffraction
Definition
An instrumental method where a dispersed sample passes through a laser beam and the angular diffraction pattern is inverted to produce a particle-size distribution. Instruments such as the Malvern Mastersizer can resolve distributions from below 0.1 micrometres to 3500 micrometres in a single run.
- Measured quantity
- Angular diffraction pattern of laser light
- Output
- Particle-size distribution
- Example instrument
- Malvern Mastersizer
- Range
- Below 0.1 micrometres to 3500 micrometres
Common questions
What forensic use does laser diffraction have beyond soil or trace evidence?+
It profiles particle-size distributions of powders, minerals, and granular trace materials in a single run, which can support comparisons between a questioned sample and a suspected source, such as matching soil or industrial powder grain-size signatures.
Why is a full distribution more informative than a single average particle size?+
Two samples can share the same mean particle size while differing sharply in how that size is distributed, so a matched or mismatched distribution shape carries more discriminating value than comparing single average figures alone.
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