Microtrac S3500, Operation And Maintenance Manual, Page: 11 / 38

Introduction
9/03 Microtrac S3500 Particle Size Analyzer Operation and Maintenance 5
Figure 1-2
Laser Safety Labels
WARNING
Laser radiation may be exposed when the top case cover or sample module door is open. Avoid direct
exposure to the beam. Do not view the beam directly or with any optical instruments.
Do not tamper with or attempt to defeat any safety interlocks. Use of controls and adjustments, or performance
of procedures other than specified by the manufacturer may result in hazardous radiation exposure.
Laser Interlock
The interlock safety feature consists of three microswitches in series which must be closed to allow the
lasers to operate. One safety interlock microswitch is closed when the access cover of the S3500 is closed.
Two additional microswitches close when the sample cell chamber access cover is closed. With both
access covers closed, the lasers can be activated under computer control.
Laser Alignment
Laser light source alignment is accomplished automatically by means of two adjusting stepping motors
under computer control. During alignment and normal operation, the laser light source is contained within
a protected compartment and not visible to the operator.