23
The readout always shows the displacement
between the Target Center and the Laser
Beam Center. When the Target Center is not
on the True Bore Center, the numbers and the
signs on the readout will change when the
target is rotated because the Target Center is
moved to a different location in relationship to
the laser beam.
Figure 9 represents the target in the NORMal
position, with the cable
down
. If each square
represents .001 in., the Target Center is .002
in. higher than the Laser Beam Center (+.002
in.) and is .007 in. to the right of the Laser
Beam Center (+.007 in.).
Figure 9 –
Target in the NORMal position
Figure 10 represents the target in the INverted
position, with the cable
up
. When the target is
rotated, the
signs
on the readout are also
rotated. Therefore, although the Target Center
appears to be to the right of and lower than the
Laser Beam Center in Figure 10, the vertical
readings are positive, and the horizontal
readings are negative. When the vertical TCE is
calculated, (INverted divided by 2)
the Target Center is .004 in. higher and .003 in.
to the right of the True Bore Center in the
NORMal position.
The table below shows the calculation of the
vertical and horizontal TSCE values.
Figure 10 –
Target in the INverted position
NORMal Vertical Reading
+.002 in.
NORMal Horizontal Reading
+.007 in.
INverted Vertical Reading
+.008 in.
INverted Horizontal Reading
-.001 in.
Total
+.010 in.
Total
+.006 in.
Divide by 2 =
Vertical TSCE
+.005
in.
Divide by 2 =
Horizontal
TSCE
+.003
in.
If you place the Laser Beam Center exactly on the True Bore Center with the target in the NORMal
position, the readings will show Ve.005 in. and Hori.003 in.
