SOUTH
ET
‐
02/05
ELECTRONIC
THEODOLITE
SERVICE
MANUAL
3
SOUTH
SURVEY
&
MAPPING
INSTRUMENT
CO.,
LTD.
3
G. Horizontal Clamp and Tangent Unit
Its case is just the same as that of vertical clamp and tangent unit. Pass it over here.
H. Level Unit
a. Plate level
The plate level with protective glass is installed on the alidade bracket and is vertical to adjustment vertical
axis unit. The level is obturated with plaster in the metal tube. There is a setscrew on the right of the metal
base with an adjusting screw which can make the left of the level rise or fall so as to adjust the plate level
axis vertical to vertical axis.
b. Circular level
As a primary leveling one, bubble of circular plate can be adjusted to move to the center directly after plate
level is well adjusted.
I. Battery Box
The battery box of ET consists of four nickel-hydrogen batteries, which normal voltage value is between
5.5V and 7V.
J. Optical Plummet
The focusing device of optical plummet is similar to the inside focusing telescope. Rotate focusing hand
wheel of eyepiece, make reticle in focus, this process is called focusing for reticle board. Rotate focusing
hand wheel in order to make the imaging of target point that is on the reticle board is in focus, too. In
addition, reticle is required to go through the prism on structure, and should go through the center of the
object lens after turning.
K. Display Unit
The display unit consists of display board, display driver, IC parellel interface, etc.
When being output from parellel interface, characters are sent to computer which exports signals and
transmits instructions to display driver. After receiving address route and external synchronic signal, display
driver acts together with clock SCL, reading in data from computer and IC, then shows with character.
L. CCD
CCD photoelectric sensor consists of infrared light-emitting diodes, CCD photoelectric receiver and other
parts. The light signal form tube emit to the encoder dick plated with transparent and opaque stripe.
According to the working principle of encoder disk signal, it measure the angle value
M. Base and Leveling Screw
Unlock the setscrew of the three-jaw base, discharge alidade and base. Place the instrument and base on the
worktable, then loosen the cap of screw, rotate the nut clockwise, turn the base upside down, loosen the
three brads on the trigonal soleplate with screwdriver to separate the leveling screws from base and separate
the base from the trigonal soleplate. Hereto, the spare parts such as leveling screw can be cleaned and oiled.
