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No. 99MBC095A
3.2.17 Recording the amount of light
• The gap measurement may be unstable if not enough laser beam passes through the gaps.
In the case shown in diagram (a) below, an adequate amount of light can be obtained as
the laser passes through gap (g) above the workpiece, even if the gap (t) is small. How-
ever, in diagram (b) where gap (t) is small, measurement will be affected. In this case,
therefore, it is necessary to have the system record the full amount of light when there is
no obstruction (workpiece or fixture) in the optical path.
Workpiece
Workpiece
t
g: Gap for the
reference beam
t
Gap
Gap
(a) Light amount can be detected normally = Auto-detecting
(b) Recording the amount of light is required
Laser beam
passes through
this gap.
Light amount
cannot be detected
(insufficient duration)
Photo-electric signal
Light amount
can be detected
Peak of the
photo-electric
signal
• Normally the amount of incident light is continuously checked so that the counting
operation can follow the change in the amount of incident light. Have the system record
the light amount following 4.4, “Recording the light amount”. It is also necessary to carry
out this operation twice or three times each year since the light amount of the system may
vary.
• If the amount of light is recorded, temperature drift of the measured data becomes larger.
• The minimum size of gap (t) that can be measured depends on each Measuring Unit as
shown below:
emanledoMtrog:paG
S005-MSLeromromm2.0
S105-MSLeromromm3.0
S305-MSLeromromm1
S605-MSLeromromm2
S215-MSLeromromm4
S615-MSLeromromm6
