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No. 99MBC095A
3. DISPLAYS AND KEY OPERATIONS
Display unit
Measuring unit 1
Measuring unit 2
SEG 1
SEG 5
EG 1
EG 2
EG 3
EG 5
EG 6
EG 7
Measuring unit 1
Measuring unit 2
Least significant digit of
program number: 0 - 4
Least significant digit of
program number: 5 - 9
Least significant digit of
program number: 0 - 4
Least significant digit of
program number: 5 - 9
c) Example of units positioned back to back
• Position two Measuring Units back to back as shown in 3) above to measure a transparent
object with the DF-type setup.
Transparent objects may not be measured with units facing each other or stacked one on
top of another.
• For information about techniques to improve the measuring accuracy refer to the measur-
ing unit user’s manual.
• Calibration and combined offset
a) Separate calibration for each Measuring Unit
Perform the calibration after selecting Segment (1 ~ 3) at the Measuring Unit 1 side
with the least significant digit of program number set to between 0 and 4 for Measuring
Unit 1, and Segment (5 ~ 7) at the Measuring Unit 1 side with the least significant digit
of program number set to between 5 and 9 for Measuring Unit 2, respectively.
b) Combined calibration
In addition to being able to perform separate calibration for each Measuring Unit, the
DF-type setup allows the use of combined calibration where segments are assigned over
two Measuring Units.
This combined calibration is effected from either combination of segments (1 + 5) or (1
+ 7).
Note that cancellation of separate calibration will also cancel the combined calibration.
IMPORTANT Since the reflection light from a large-diameter workpiece (skip phenomenon) is
generated in DF-type measurement, the accuracy decreases to some extent, com-
pared with the linearity of each measuring unit. The following figure shows that
undesired values e1 and e2 are generated due to reflected light. The undesired
value (e1, e2) increases with the diameter of the workpiece (e2 > e1). This depends
on the reflectivity of the surface.
Therefore, if each measuring unit is calibrated independently using a small diameter
gage, an error may result if a large diameter is measured.
