David White L6-20, Руководство пользователя

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To establish vertical lines and planes,
first level the instrument, then release the
locking levers which hold the telescope in
the level position.
Swing the telescope vertically and
horizontally until the line to be established
is directly on the vertical cross hair. If the
telescope is rotated up or down, each
point cut by the vertical cross hair should
be in a vertical plane with the starting
point.
CHECkING CALIBRATION
Your David White instrument must be
serviced and repaired by an authorized
David White service center.
You may, however, choose to check
the instrument yourself to make sure it is
properly adjusted. A simple, inexpensive
setup can be established to check an
instrument’s line of sight:
1. Locate an area to set up a tripod
that is 10 feet (3 m) away from a wall,
post, permanent shelving, etc. and
approximately 75 ft to 100 ft (22 m
to 30 m) away at a 90°angle from
another wall, post, etc.
2. Using an automatic level or other
high-accuracy instrument known
to be in perfect adjustment, secure
it to the tripod and level it following
instructions in the instrument’s
owner’s manual.
3. Make sure the tripod is on a firm base
and mark the location of the tripod
shoe points. These marks can be
used for future reference.
4. After the instrument has been
completely leveled, sight on the wall
that is 10 feet (3 m) away.
5. Place a two-foot section of rod ribbon
on the wall so the horizontal cross
hair of the instrument intersects the
middle of the two-foot section.
6. Rotate the instrument 90°and sight
on the wall that is about 75 feet to
100 feet (22 m to 30 m) away.
7. Place a two-foot section of rod ribbon
on that far wall so the horizontal cross
hair of the instrument intersects the
middle of the two-foot section (as
in Step 5). Adjust this rod ribbon so
that it reads the same exact point as
the closer ribbon. Secure ribbon with
tape or glue.
8. Now put the instrument to be
checked on the tripod and take a
reading on the ribbon 10 feet (3 m)
away. Record the reading.
9. Rotate the instrument 90° and take a
reading on the distant ribbon.
10. Compare the two readings. If there
is a difference in the two readings,
your instrument needs adjusting by a
David White service facility.
If you have questions about checking
for calibration, contact David White or a
repair facility. All actual adjusting of the
instrument must be done by a qualified
service facility.