Operation:
Taking Measurements
The Micrometer features a very shallow depth
of focus that allows the distance between
two points at different depths to be easily
measured. Areas within the focal plane will
appear sharp while areas above and below
this plane will be out of focus.
The Micrometer does not feature prismatic
correction, so the image is inverted.
▪
Step 1
Shine flashlight
through the eyepiece
to create a pin-point
spot. Use spot to
position Micrometer
directly over region of
interest (ROI).
▪
Step 2
Without moving the
Micrometer, place lit
flashlight in desired
flashlight receptacle
on base.
▪
Step 5
Focus into the bottom of damaged area (“Surface
B” in diagram below).
▪
Step 6
Record depth shown on digital display.
▪
Step 7
This step is for verification only. Re-focus on
the top surface, display should show “0.0000”.
▪
Step 8
Repeat steps 3-7 for verification.
Transparencies
For transparent materials it is necessary to know
the refraction index of the specific material. The
Micrometer reading must be multiplied by the
refraction index for an accurate result.
For instance, if measuring the overall thickness
of a plexiglass window and the Micrometer reads
0.3600”, the actual thickness of the window is
0.3600 x 1.49 (the refractive index of plexiglass),
or 0.5364”.
Bubbles inside transparent materials are air
space and not subject to the refraction index.
Hold the base of micrometer for support while
focusing to prevent it from moving.
▪
Step 3
Look through the eyepiece and use
the focus adjustment to bring the
primary surface (the undamaged
surface directly next to the scratch or
pit, “Surface A” in diagram at right)
into sharp focus.
At 100X magnification, the
objective lens will be approximately
1/4” over the target when in focus.
▪
Step 4
Press the “ZERO/ABS” button
(display should now read “0.0000”).
