| TN
FTS 1294-2 |
UNDERSTANDING HOW THE SYSTEM WORKS |
HOW THE MEASUREMENT SYSTEM WORKS |
Dry film measurement is performed by first boring a shallow
crater in through the coating(s) surface and into the substrate.
By boring a shallow crater through the paint films to the
substrate, exposing the different layers of paint, the crater
is then viewed through the video microscope system. By magnifying
this crater through the video microscope system and viewing
it on the high resolution monitor, the different film layers
are visible. The image on screen is magnified up to approximately
320 linear magnification. The actual measurement is done with
the digital micrometer using a cross hair line generator to
line up the beginning and termination points for the measurement.
The reading is then divided by ten. |
Technical Details |
| To
achieve a very high degree of accuracy the angle of the borer
bit used shaves a very shallow crater. You need only to penetrate
through the film coating(s) exposing the substrate to obtain
a measurement. The film layer width exposed by the borer bit’s
shallow angle is 10 times greater then the actual film thickness. |
Measurement example showing benifits of ten X factoring |
| Sample
film thickness is .0008" (8/10,000 commonly referred
to as eight tenths) thick: - the width of the film layer exposed
by the borer bit is 10 times greater than the actual paint
thickness, i.e. .0008 x 10 =.008 (8/1,000), this width is
readily measured by the digital micrometer head reading to
a resolution of .00005" (50 millionths of an inch), and
when projected on to the monitor screen this is further enlarged.
On screen this image is approximately 2" wide, so it
is an easy matter to line up the cross hair on the enlarged
image. Any error or lack of consistency on the part of the
operator in lining up the cross hair to the edge of the film
is minimized. This error is only 1/10 of the actual film thickness,
repeatability of better than +/- .00005 (50 millionths of
an inch) is readily obtained. |
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