2
Checklist
•
Transit in orange box. In the case should also be
•
a plumbob and a 5/64" drill bit or the original adjustment tools
•
a magnifying glass for reading the vernier
•
Tripod with 8.5 cm wide screw-on mount.
•
Stadia rod with rod level.
•
Tape if desired.
•
Survey pins if desired.
Setup
1. Set up tripod, getting the top close to horizontal.
2. Carefully mount transit on tripod, as close as possible to over the survey point.
3. Level in two directions using the plate levels, each in
line with opposite pairs of leveling screws. Rotate
horizontal circle 180° to check if bubbles stay level. If
necessary try again from this position. If you cannot get
the bubble to stay centered 180° apart, you'll need to
adjust the plate level (see the instructions). This is
commonly needed, so make sure you have the tool that
exactly fits the adjustment screws.
4. To position the transit exactly over a survey point
using the plumbob, after leveling you'll need to loosen
two
adjacent
leveling screws to be able to move the
transit on the tripod plate. You can only move it a short
distance – you may need to reposition your tripod and
relevel if you're off by more than that. Then level it
again.
5. Once leveled with the plate level, you can level to
greater accuracy with the telescope bubble:
•
Bring the telescope over a pair of leveling
screws and center the telescope bubble by using
the vertical clamp and tangent screw.
•
Rotate the telescope 180° in azimuth. If the
telescope
bubble does
not come to
the center,
bring it
halfway to
the center by
turning the
vertical
Adjusting a plate bubble level
After centering the bubble in one position,
rotate the horizontal circle 180° and if this
is off you need to adjust that plate level:
•
Use the leveling screws to correct
the bubble
half way
to center, then:
•
Use the smooth part of a 5/64" drill
bit, or the tool to adjust one or the
other side of the plate level up or
down to get the bubble centered.
You'll be turning the top and bottom
capstan screws the same direction to
move that side of the bubble up
(counter-clockwise) or down
(clockwise). Note that you have to
turn one to loosen it, and the other
the same direction to tighten it, in a
new position.
•
If it's off very much at all, you'll
have to repeat this to get it closer
and closer.
Clamps and tangent screws
clamp
tangent
screw
There are three clamp and tangent screw
pairs: two (upper and lower) for horizontal
circle adjustments, and one for vertical. In
each case, the clamp is loosened to move the
transit more than a few degrees, then the
clamp is tightened for fine adjustment with
the tangent screw
