HP 8163A User Manual page 11

Safety Summary
Non-USA (All Tunable Laser Source Modules HP 81640A/80A/82A/89A)
These laser safety warning labels are fixed on the outside of the HP 8164A
Lightwave Measurement System before shipment.
A sheet of laser safety warnings is included with the laser module. You
MUST stick the labels in the local language onto the outside of the
instrument, in a position where they are clearly visible to anyone using
the instrument.
You MUST return instruments with malfunctioning laser boxes to
an HP Service Center for repair and calibration.
The laser module has a built in safety circuitry which will disable
the optical output in the case of a fault condition.
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