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No. 99MBC071A
5. MEASUREMENT MODE
5.2 Other Functions
From the ready state it is possible to activate the following modes.
5.2.1 Key lock
Press the
SHIFT
and
LOCK
/
UNIT
keys to activate the key lock mode. Subsequently, key
operations other than
SHIFT
and
LOCK
/
UNIT
keys will not be accepted. To cancel this mode,
press the same keys again.
However, if the key lock mode is initiated by the “LOCK” command from the RS-232C/GP-
IB interface, it can not be canceled by any key operation.
The only way the key lock mode is canceled is by turning the power off.
5.2.2 Displaying the measuring position
• If the
SHIFT
and
READ
keys are pressed in the ready state, the measuring position (focal
position) display mode is entered. The ready state can be returned to if the
READ
key or
SET
key is pressed.
• The displayed value is not defined, but a value that is proportional to the beam diameter at
the measuring position.
Since the measurement is defined at the focal position where the displayed value is the
smallest, take measurements at a position as close to the focal position as possible.
If the measured position is off the focal position, the measurement accuracy will be
reduced.
PROG
Measuring position
• Beam diameter at each position
The laser scanning beam is stopped down so that it has a minimum diameter at the measure-
ment position (focal position). Since the beam diameter gets thicker the farther it gets from the
focal point, the repeatability will be reduced if measurements are taken far out.
Therefore, always perform measurement at the focal position.
If a very thin workpiece is measured outside the measuring region, “Err-0” (no objective
workpiece present) may be displayed.
f–θ Lens
Beam diameter at each position
Focal position
• Check the measurement position in the up/down direction with the W.P. LED.
