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Single-Fiber Thickness and Swelling

Laser Scanning Microscopy


The laser micrometer in action.  The red laser light is just visible on the center of the fiber.  In the tests the fibers are rotated to get an average diameter and a measure of ellipticity.  Hairs are usually sampled in several points to get a representative reading.

Beautiful Hair Model
Single-Fiber Hair Thickness and Swelling
Laser Scanning Microscopy
If you want to show that your product is increasing hair thickness, or volume, it is useful to perform hair diameter measurements.  Additionally, since hair swells differently in water after various damaging treatments, hair swelling tests are also useful for measuring hair damage prevention and repair.

Hair diameter measurements involve shining a laser onto the fiber.  A detector behind the fiber measures the size of the shadow created by the laser light and uses this to calculate the hair diameter.  Hair diameter is thus measured without any contact with the instrument.  The instrument can also measure hair ellipticity.

TRI Publications
Evans (2018)
For more information please contact:
TRI Princeton
+1 (609) 430 - 4820

A sample being tested on the laser micrometer.

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