David White LT8-300, Руководство пользователя

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To determine the fraction, or minutes:
- Start at 0 on the vernier and read up
the vernier scale (in the same direction
as you’re reading the degree scale) until
you find a minute line that coincides
exactly with a degree line.
- 41° was the last degree line passed on
the circle.
Reading to the right on the vernier
scale, the minute line which coincides
exactly with a degree line is 25’
(Reading is 41° 25’).
Remember, each line on the vernier scale
represents 5’, so you will be reading 5’,
10’, etc. The circle degree scale is being
read to the left.
When reading the circle degree scale to
the left, read up the vernier scale in the
same direction.
- Reading to the left on the vernier scale
8 , the minute line which coincides
exactly with a degree line is 45’.
The vertical arc 14 is read in the same
way. 21° was the last degree line passed
(when reading the arc degree scale to the
right).
- Reading to the right on the vernier
scale, the minute line which coincides
exactly with a degree is 30’.
Sighting and Focusing the
Telescope
The telescope 1 provides a sharp image
magnified 26 times. This means the
object sighted appears 26 times closer
than it would with the naked eye.
Avoid touching the tripod while sighting.
- Aim the telescope at the object and
sight first through the notches
2
on
the top of the level vial for preliminary
sighting. Look through the telescope
eyepiece 3 and focus the crosshairs
using the eyepiece adjuster
3
.
- Then bring the object into focus using
the focusing knob 4 .
- Rotate the instrument until the
crosshairs are positioned on or near
the target. Tighten the horizontal clamp
9 and make final settings with the
tangent fine tuning knob 10 to bring the
crosshairs exactly on point.
When sighting through the telescope,
keep both eyes open. You will find that
this eliminates squinting, will not tire your
eyes and gives the best view through the
telescope.
Remember to avoid touching the tripod
while sighting.
Stadia Reticle.
All LT8-300 series instruments have a
glass stadia reticle with two additional
horizontal lines for use in determining
distance.
Stadia
Hairs
A B
L
Read the length “ ” of a level rod shown
between the stadia hairs.