Nikon eclipse lv150 Instruction Manual page 30

Coarse focus stopper
The coarse focus stopper restricts the movement of the coarse focus knob so that the stage cannot
be raised higher than the position the operator specifies.
When the coarse focus stopper ring is rotated in the direction of the arrow (labeled "CLAMP→")
on the microscope base, the coarse focus knob cannot be used to move the stage any higher.
(Movement of the stage by the fine focus knob is not restricted.)
For example, once the coarse focus knob is clamped in place at the focus position, a rough focus
can be attained the next time simply by raising the stage until the coarse focus knob cannot be
turned any further.
If the coarse focus stopper is not being used, be sure to turn the ring in the direction opposite to the
arrow on the microscope base as far as it goes.
[Example usage]
With the sample in focus, turn the coarse focus
stopper ring as far as it goes in the direction of the
arrow (labeled "CLAMP→") on the microscope
base (about 3/4 revolution). The coarse focus
stopper is now clamped in position.
When changing the sample, lower the stage by
turning only the coarse focus knob.
After changing the sample, gently raise the stage by
turning only the coarse focus knob as far as it goes.
The sample should be roughly in focus when the
stage has been raised as far as it goes. Use the fine
focus knob to bring the sample into perfect focus.
28
Clamp
Coarse focus
stopper ring