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Chapter 3 Preparation and inspection before observation
Inspecting the O-ring
Inspect the O-ring for cuts or gaps.
CAUTION
• If the O-ring is positioned incorrectly or chips exist on its surface, water can get into the joint
area between the insertion tube and optical adapter which may cause malfunction or
damage. In some cases, the illumination does not light.
There are two O-rings on the distal end of the insertion tube.
If the large O-ring on the tip of the insertion tube is not present then the area
under it is visible because it is colored yellow. The area under the small O-ring
for the cleaning nozzle is not colored.
CAUTION
• If the O-ring is cut, nicked or shows any abnormality, put silicon grease on the spare O-ring
provided with the optical adapter and replace the abnormal O-ring with the spare O-ring. You
should periodically replace the O-ring.
O-ring (large)
O-ring (small)