APPLICATION NOTE
FORENSIC
INSPECTION OF CYLINDERS
L.E.S.S. SA
Chemin de la Dent d’Oche, 1A
1024 Ecublens, Switzerland
www.less-sa.com
info@less-sa.com
+41 21 552 07 10
AVOIDING REFLECTIONS ON THE SURFACE
OF CYLINDRICAL PARTS.
CONTRASTING DEFECTS AND SURFACE
STRUCTURE.
Using standard illuminations to inspect reflective cylindrical
parts creates parasite reflections of the light source on the
surface to inspect, preventing a sharp observation. The
metal rod used in this application has a diameter of 2 mm.
The L.E.S.S. lighting systems provide a perfect illumination
of the entire visible surface and speeds up inspection.
FEATURES OF L.E.S.S. LIGHTING SYSTEMS APPLIED
•
Features of L.E.S.S. lighting systems applied
•
Darkfield illumination
•
Easy adjustment of working distance
•
Uniform and diffuse illumination with neutral white
light (5400 °K)
•
Avoidance of reflections on mirroring surfaces
•
Partly covering the illumination ring
•
Free view and easy access to the specimen
•
No heat dissipation from the ring lights
APPLICATION
Fig.1 has been taken with in a traditional configuration: the
lighting system lights the sample from above, generating
parasite reflections on the surface to inspect as per shown
on Fig. 1. As a consequence, marks on the surface are
hardly visible.
Fig.2 has been taken with a diffuser: an opened
transparent coffee cup, illuminated from an external light
source. While widely used, this set-up actually extends
the reflections and diminishes the contrasts, covering the
marks the observer would like to reveal. The dark strip on
top of the cylinder is the mirror image of the microscope
objective.
Fig.3 has been taken with the L.E.S.S. Darkfield
illumination. In this low angle illumination configuration,
the reflections are totally eliminated: the surface structure
is revealed in sharp contrasts, marks are clearly visible and
well defined.
Fig.1
Cylinder lit by L.E.S.S. Brightfield
illumination
RISK CLASS 0
EN 62471 : 2006
Fig.3
Cylinder lit by L.E.S.S. Darkfield
illumination
Fig.2
Cylinder lit with a «Coffee Cup»
diffuser
EYE-SAFE
CLASS 1 LASER PRODUCT
ICE 60825-1 2014-05
L.E.S.S. SA
Chemin de la Dent d’Oche, 1A
1024 Ecublens, Switzerland
www.less-sa.com
info@less-sa.com
+41 21 552 07 10
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