B-70315EN/02 3.INSTALLATION
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(13) Conduct an oscillator vacuum leakage test.
Check the oscillator for any internal leakage.
When performing the leakage check, use the automatic leakage
check function described in Subsection 3.3.4.
If there is internal leakage, locate the leakage according to the
leakage location method described in Subsection 3.3.5.
(14) Check that the laser gas pressure is controlled normally.
(a) Set all bits of parameter No. 15025 through parameter No.
15028 to 0 because only the pressure control operation is to
be checked, without causing discharge.
Check that alarm Nos. 4073 and 4078 are not issued. If one
of the alarms is issued, see the solution in Section 5.2, and
take appropriate action.
(b) After completing the checking, reset the changed
parameters to their original settings.
(15) Start the laser oscillator to perform discharge aging. See
Subsection 3.3.6 to start the aging function.
(16) Check the oscillation characteristics and output. See Subsections
3.3.7, 3.3.8, and 3.3.9 for details of the check method.
Check items
(a) Check that the correction coefficient is 1100 or less.
(b) Oscillation characteristic check :
Check that the discharge voltage during base discharge and
when a rated output is specified is within the factory-set
value plus 200 V.
If the correction coefficient or discharge voltage exceeds the
maximum, repeat discharge aging.
(c) Discharge margin check : Check that a margin is provided.
(d) Voltage margin check : Check that no alarm is issued.
(17) Check the laser beam mode.
CAUTION
A beam mode deviation may occur depending on
the transportation method and storage condition.
When installing the oscillator, be sure to perform
this step. A mode deviation does not mean a
failure. Perform alignment by following the
procedure described in Subsection 8.3.2.
Follow the check procedure described in Subsection 3.3.10 to
ensure the following:
Check items
(a) Check that there is no significant difference from the mode
specified in the data sheets attached to the oscillator.
(b) Check that the mode shape is perfectly circular.
(c) Check that no interference fringes can be observed nearby.
If an abnormality is found, make mirror adjustments by
following the procedure described in Subsection 8.3.2.