Sokkia DT7C User manual

SURVEYING INSTRUMENTS
OPERATOR'S MANUAL
DT7C
DT20C
Electronic Digital Theodolite

This is the mark of the Japan Surveying
Instruments Manufacturers Association.

DT7C
DT20C
Electronic Digital Theodolite
• Thank you for selecting the DT7C/DT20C.
• Before using the instrument, please read this operator's manual
carefully.
• Verify that all equipment is included. C"12.1 Standard
Equipment"
• The specifications and general appearance of the instrument may
be altered at any time and may differ from those appearing in
brochures and this manual.
• Some of the diagrams appearing in this manual may be simplified
for easier understanding.
SURVEYING INSTRUMENTS
OPERATOR'S MANUAL

ii
HOW TO READ THIS MANUAL
The following conventions are used in this manual.
• Functions differ depending on the theodolite model used.
• Screens and illustrations appearing in this manual are of DT7C.
Symbols
The following conventions are used in this manual.
G: Indicates precautions and important items which should be
read before operations.
C: Indicates the chapter title to refer to for additional information.
$: Indicates supplementary explanation.
&: Indicates an explanation for a particular term or operation.
{Key} : Indicates operation keys.

iii
CONTENTS
1. PRECAUTIONS FOR SAFE OPERATION ........ 1
2. PRECAUTIONS ................................................. 4
3. PARTS OF THE INSTRUMENT ........................ 6
4. INSTALLING/REMOVING THE BATTERY........ 9
5. SETTING UP THE INSTRUMENT................... 11
5.1 Centering .............................................................11
5.2 Leveling................................................................12
6. FOCUSING AND TARGET SIGHTING............ 14
7. POWER ON ..................................................... 15
8. MEASUREMENT ............................................. 16
8.1 Measuring the horizontal angle between 2 points (H
angle 0) ................................................................16
8.2 Set Horizontal Circle to a Required Value (Horizon-
tal angle hold) ......................................................17
8.3 Changing Horizontal Angle Display Mode............18
8.4 Changing Vertical Angle Display Mode................18
8.5 Stadia Survey.......................................................19
9. CHANGING INSTRUMENT OPTIONS ............ 21
10. ERROR MESSAGES ....................................... 28
11. CHECKS AND ADJUSTMENTS ...................... 29
11.1Plate Level ...........................................................29
11.2Circular Level .......................................................30
11.3Reticle ..................................................................31
11.4Optical Plummet...................................................33
12. STANDARD EQUIPMENT ............................... 35
12.1Standard Equipment ............................................35
12.2Optional Accessories ...........................................36
12.3Layout Plan ..........................................................38
13. APPENDICES .................................................. 39
13.1Battery Selection..................................................39
14. SPECIFICATIONS ........................................... 40
15. REGULATIONS ............................................... 42

iv

1
1. PRECAUTIONS FOR SAFE OPERATION
Read this manual before using the instrument.
For the safe use of the product and prevention of injury to operators and other
persons as well as prevention of property damage, items which should be
observed are indicated by an exclamation point within a triangle used with
WARNING and CAUTION statements in this operator's manual.
The definitions of the indications are listed below. Be sure you understand them
before reading the manual's main text.
Definition of Indication
Definition of Symbols
CWARNING
Ignoring this indication and making an operation error
could possibly result in death or serious injury to the
operator.
CCAUTION
Ignoring this indication and making an operation error
could possibly result in personal injury or property
damage.
JThis symbol indicates items for which caution (hazard warnings
inclusive) is urged. Specific details are printed in or near the symbol.
DThis symbol indicates items which are prohibited. Specific details are
printed in or near the symbol.
IThis symbol indicates items which must always be performed. Specific
details are printed in or near the symbol.

1. PRECAUTIONS FOR SAFE OPERATION
2
General
CWARNING
CCAUTION
DDo not use the unit in areas exposed to high amounts of dust or ash, in
areas where there is inadequate ventilation, or near combustible
materials. An explosion could occur.
GDo not perform disassembly or rebuilding. Fire, electric shock or burns
could result.
DNever look at the sun through the telescope. Loss of eyesight could
result.
DDo not look at reflected sunlight from a prism or other reflecting object
through the telescope. Loss of eyesight could result.
DDirect viewing of the sun using the telescope during sun observation will
cause loss of eyesight. Use a solar filter (option) such as that in
“12.2 Optional Accessories”
EWhen securing the instrument in the carrying case make sure that all
catches, including the side catches, are closed. Failure to do so could
result in the instrument falling out while being carried, causing injury.
DDo not use the carrying case as a footstool. The case is slippery and
unstable, so a person could slip and fall off it.
DDo not place the instrument in a case with a damaged catch, belt or
handle. The case or instrument could be dropped and cause injury.
DDo not wield or throw the plumb bob. A person could be injured if struck.
ESecure handle to main unit with locking screws. Failure to properly
secure the handle could result in the unit falling off while being carried,
causing injury.
ETighten the adjustment tribrach clamp securely. Failure to properly
secure the clamp could result in the tribrach falling off while being carried,
causing injury.

3
1. PRECAUTIONS FOR SAFE OPERATION
Power Supply
CWARNING
CCAUTION
Tripod
CCAUTION
DDo not short circuit. Heat or ignition could result.
DDo not heat or throw batteries into fire. An explosion could occur, resulting
in injury.
ETo prevent shorting of the battery in storage, apply insulating tape or
equivalent to the terminals. Otherwise shorting could occur, resulting in
fire or burns.
DDo not use battery if wet. Resultant shorting could lead to fire or burns.
DDo not touch liquid leaking from batteries. Harmful chemicals could cause
burns or blisters
EWhen mounting the instrument to a tripod, tighten the centering screw
securely. Failure to tighten the screw properly could result in the
instrument falling off the tripod, causing injury.
ETighten securely the leg fixing screws of the tripod on which the
instrument is mounted. Failure to tighten the screws could result in the
tripod collapsing, causing injury.
DDo not carry the tripod with the tripod shoes pointed at other persons. A
person could be injured if struck by the tripod shoes.
EKeep hands and feet away from the tripod shoes when fixing the tripod in
the ground. A hand or foot stab wound could result.
ETighten the leg fixing screws securely before carrying the tripod. Failure
to tighten the screws could lead to the tripod legs extending, causing
injury.

4
2. PRECAUTIONS
Precautions concerning water and dust resistance
DT conforms to IP66 specifications for waterproofing and dust resistance when
the battery cover is closed and connector caps are attached correctly.
• Be sure to close the battery cover and correctly attach the connector caps to
protect the DT from moisture and dust particles.
• Make sure that moisture or dust particles do not come in contact with the inside
of the battery cover, terminal or connectors.
Contact with these parts may cause damage to the instrument.
• Make sure that the inside of the carrying case and the instrument are dry before
closing the case. If moisture is trapped inside the case, it may cause the
instrument to rust.
Other precautions
• If the DT is moved from a warm place to an extremely cold place, internal parts
may contract and make the keys difficult to operate. This is caused by cold air
trapped inside the hermetically sealed casing. If the keys do not depress, open
the battery cover to resume normal functionality. To prevent the keys from
becoming stiff, remove the connector caps before moving the DT to a cold
place.
• Never place the DT directly on the ground. Sand or dust may cause damage to
the screw holes or the centering screw on the base plate.
• Protect the DT from heavy shocks or vibration.
• Never carry the DT on the tripod to another site.
• Turn the power off before removing the battery.
• When placing the DT in its case, first remove its battery and place it in the case
in accordance with the layout plan.
C"12.3 Layout Plan"
• Consult your local dealer before using the instrument under special conditions
such as long periods of continuous use or high levels of humidity. In general,
special conditions are treated as being outside the scope of the product
warranty.
Maintenance
• Always clean the instrument before returning it to the case. The lens requires
special care. First, dust it off with the lens brush to remove tiny particles. Then,
after providing a little condensation by breathing on the lens, wipe it with a soft
clean cloth or lens tissue.
• If the display is dirty, carefully wipe it with a soft, dry cloth. To clean other parts
of the instrument or the carrying case, lightly moisten a soft cloth in a mild