Geokon 6300 User manual

Instruction Manual
Model 6300
Vibrating Wire In-Place Inclinometer
No part of this instruction manual may be reproduced, by any means, without the written consent of Geokon®.
The information contained herein is believed to be accurate and reliable. However, Geokon®assumes no responsibility for errors,
omissions or misinterpretation. The information herein is subject to change without notification.
Copyright © 1995-2019 by Geokon®
(Doc Rev Q, 05/01/19)

Warranty Statement
Geokon warrants its products to be free of defects in materials and workmanship, under normal
use and service for a period of 13 months from date of purchase. If the unit should malfunction,
it must be returned to the factory for evaluation, freight prepaid. Upon examination by Geokon,
if the unit is found to be defective, it will be repaired or replaced at no charge. However, the
WARRANTY is VOID if the unit shows evidence of having been tampered with or shows
evidence of being damaged as a result of excessive corrosion or current, heat, moisture or
vibration, improper specification, misapplication, misuse or other operating conditions outside of
Geokon's control. Components which wear or which are damaged by misuse are not warranted.
This includes fuses and batteries.
Geokon manufactures scientific instruments whose misuse is potentially dangerous. The
instruments are intended to be installed and used only by qualified personnel. There are no
warranties except as stated herein. There are no other warranties, expressed or implied, including
but not limited to the implied warranties of merchantability and of fitness for a particular
purpose. Geokon is not responsible for any damages or losses caused to other equipment,
whether direct, indirect, incidental, special or consequential which the purchaser may experience
as a result of the installation or use of the product. The buyer's sole remedy for any breach of this
agreement by Geokon or any breach of any warranty by Geokon shall not exceed the purchase
price paid by the purchaser to Geokon for the unit or units, or equipment directly affected by
such breach. Under no circumstances will Geokon reimburse the claimant for loss incurred in
removing and/or reinstalling equipment.
Every precaution for accuracy has been taken in the preparation of manuals and/or software,
however, Geokon neither assumes responsibility for any omissions or errors that may appear nor
assumes liability for any damages or losses that result from the use of the products in accordance
with the information contained in the manual or software.

TABLE of CONTENTS
1. INTRODUCTION ...................................................................................................................................................1
1.1 TILT SENSOR CONSTRUCTION..............................................................................................................................2
2. INSTALLATION ....................................................................................................................................................3
2.1 PRELIMINARY TESTS............................................................................................................................................3
2.2 MODEL 6300 ASSEMBLY AND INSTALLATION .....................................................................................................3
2.2.1 Uniaxial System ..........................................................................................................................................4
2.2.2 Biaxial System.............................................................................................................................................5
2.3 FLUID DAMPING ..................................................................................................................................................7
2.4 SPLICING AND JUNCTION BOXES..........................................................................................................................7
3. TAKING READINGS.............................................................................................................................................8
3.1 GK-404 READOUT BOX.......................................................................................................................................8
3.1.1 Operating the GK-404 ................................................................................................................................8
3.2 GK-405 READOUT BOX.......................................................................................................................................9
3.2.1 Connecting Sensors.....................................................................................................................................9
3.2.2 Operating the GK-405 ................................................................................................................................9
3.3 GK-403 READOUT BOX (OBSOLETE MODEL)....................................................................................................10
3.3.1 Connecting Sensors...................................................................................................................................10
3.3.2 Operating the GK-403 ..............................................................................................................................10
3.4 MEASURING TEMPERATURES.............................................................................................................................10
4. DATA REDUCTION ............................................................................................................................................11
4.1 INCLINATION CALCULATION..............................................................................................................................11
4.2 TEMPERATURE CORRECTION .............................................................................................................................11
4.3 DEFLECTION CALCULATION ..............................................................................................................................12
4.4 ENVIRONMENTAL FACTORS...............................................................................................................................12
5. TROUBLESHOOTING........................................................................................................................................13
APPENDIX A. SPECIFICATIONS.........................................................................................................................14
A.1 VIBRATING WIRE TILT SENSOR ........................................................................................................................14
A.2 THERMISTOR (SEE APPENDIX BALSO) ..............................................................................................................14
APPENDIX B. THERMISTOR TEMPERATURE DERIVATION.....................................................................15
APPENDIX C. EXCITATION AND READOUT PARAMETERS......................................................................16
C.1 EXCITATION ......................................................................................................................................................16
C.2 EXCITATION FREQUENCY..................................................................................................................................16
C.3 OFFSET..............................................................................................................................................................16
APPENDIX D. ADDRESSABLE SYSTEMS..........................................................................................................17
APPENDIX E. TYPICAL CALIBRATION REPORT ..........................................................................................18

FIGURES
FIGURE 1-MODEL 6300 TILT SENSOR ASSEMBLY ........................................................................................................ 1
FIGURE 2-MODEL 6300 TILT SENSOR .......................................................................................................................... 2
FIGURE 3-TYPICAL INSTALLATION .............................................................................................................................. 3
FIGURE 4-BOTTOM WHEEL ASSEMBLY WITH SAFETY CABLE...................................................................................... 4
FIGURE 5-BIAXIAL SENSOR ASSEMBLY ........................................................................................................................ 5
FIGURE 6-BIAXIAL SENSOR ORIENTATION................................................................................................................... 5
FIGURE 7-TOP SUSPENSION.......................................................................................................................................... 6
FIGURE 8-LEMO CONNECTOR TO GK-404 ................................................................................................................... 8
FIGURE 9-LIVE READINGS –RAW READINGS............................................................................................................... 9
FIGURE 10 -DEFLECTION INTERVALS...........................................................................................................................12
FIGURE 11 -SAMPLE MODEL 6300 CALIBRATION REPORT...........................................................................................18
TABLES
TABLE 1-MODEL 6300 TILT SENSOR SPECIFICATIONS ................................................................................................14
TABLE 2-THERMISTOR RESISTANCE VERSUS TEMPERATURE .....................................................................................15
EQUATIONS
EQUATION 1-CALCULATION OF TILT (LINEAR)...........................................................................................................11
EQUATION 2-CALCULATION OF TILT (POLYNOMIAL)..................................................................................................11
EQUATION 3-TEMPERATURE CORRECTION .................................................................................................................11
EQUATION 4-HORIZONTAL DISPLACEMENT CALCULATION ........................................................................................12
EQUATION 5-RESISTANCE TO TEMPERATURE .............................................................................................................15

1
1. INTRODUCTION
The Geokon Model 6300 Vibrating Wire In-Place Inclinometer system is designed for long-term
monitoring of deformations in structures such as dams, embankments, foundation walls and the
like. The basic principle is the utilization of tilt sensors to make accurate measurement of
inclination, over segments, in boreholes drilled into the structure being studied. The continuous
nature of the instrument allows for very precise measurement of changes in the borehole profile
to be measured. The instrument is installed in standard grooved inclinometer casing (Figure 1).
Figure 1 - Model 6300 Tilt Sensor Assembly
Plan View
Sensor Housing
Stationary Wheel
Spring Tensioned Wheel
Connecting Tube
Inclinometer Casing
Instrument Cable

2
1.1 Tilt Sensor Construction
The sensor comprises a pendulous mass which is supported by a vibrating wire strain gauge and
an elastic hinge (Figure 2). The strain gauge senses the changes in force caused by rotation of the
center of gravity of the mass. The mass and sensor are enclosed in a waterproof housing which
includes components for connecting the sensor to wheel assemblies and/or other sensors. The
wheel assemblies centralize the sensors and allow the assembly to be lowered into the casing.
Swivel joints are included to prevent the wheel assemblies from running out of the casing
grooves due to spiral problems. Stainless steel tubing is used to connect the transducer and wheel
assemblies together, and the whole string is normally supported from the top of the casing.
Biaxial systems use two transducers mounted at 90°to each other.
To prevent damage during shipment the tilt sensors are locked in place by means of a
locking clamp screw. This slotted-head clamp screw must be removed and replaced by a
Phillips-head seal screw, (provided in the zip-lock bag), to render the tiltmeter operative.
Figure 2 - Model 6300 Tilt Sensor

3
2. INSTALLATION
2.1 Preliminary Tests
Prior to installation, the sensors need to be checked for proper
operation. Each tilt sensor is supplied with a calibration report
that shows the relationship between readout digits and
inclination. The tilt sensor electrical leads (usually the red and
black leads) are connected to a readout box (see Section 3 for
readout instructions) and the current reading compared to the
calibration readings. After backing-off the clamp screw three
full turns, carefully position the sensor against a vertical
surface and observe the reading. It will take a few seconds to
come to equilibrium and the sensor must be held in a steady
position. The readings should be within ±200 digits of the
factory reading, re-tighten the clamp screw three turns.
Note: Vibrating wire tilt sensors are shock sensitive and
severe shocks can cause a permanent offset or even break
the suspension. (The unit will not survive a two foot (0.5 m)
drop onto a hard surface). When transporting the tiltmeter
tighten the locking clamp screw.
Checks of electrical continuity can also be made using an
ohmmeter. Resistance between the gauge leads should be
approximately 180 Ω, ±10 ohms. Remember to add cable
resistance when checking (22 AWG stranded copper leads are
approximately 14.7Ω/1000' or 48.5Ω/km, multiply by two for
both directions). The resistance between the green and white
leads varies with temperature. Compare the measured
resistance and ambient temperature to the factors shown in
Table 2 in Appendix B. The resistance between any conductor
and the shield should exceed two megohm.
2.2 Model 6300 Assembly and Installation
1) Connect the safety cable to the bottom wheel assembly.
(See Figure 3.) This is strongly recommended. Not only
can it be used to retrieve the assembly in the event that one
of the joints breaks loose, but it is also very useful in
lowering the assembly into the casing. The alternative is to
hold the tube sections with vice-grips at the top of the
casing.
The bottom anchor is labeled and has no Universal joint,
just the swivel. The safety cable has a loop at its bottom
end which fits over the long bolt used to hold the bottom
anchor to the first tube section. This is shown in Figure 3.
The cable eyebolt is trapped between two nuts.
Figure 3 - Typical Installation
Top Support
Pr ot ect i v e Cap
Gage Cabl e
Incl inometer
Wheel A ssembl y
Sensor A ssembl y
Gage Tubing
Bottom Cap
Cable Connector
Casi ng

4
Figure 4 - Bottom Wheel Assembly with Safety Cable
2) Connect the first length of gauge tubing to the bottom wheel assembly. The length of tube is
shown in the table supplied with this manual. (In some cases, two tubes are joined together
by a special union.) Use the 10-32 screws and nuts, and a thread locking cement to make this
joint.
3) The next step is to attach the uniaxial or biaxial sensor assembly.
2.2.1 Uniaxial System
The uniaxial sensor is delivered unattached to its wheel assembly and should be attached
using the two 10-32 nuts and cap screws supplied. The tongue of the sensor fits inside the
slot of the wheel assembly with the orientation set such that the A+ direction marked on
the sensor is aligned on the same side as the fixed wheel on the wheel assembly. Tilts in
the positive direction yield increasing readings in digits.
Vibrating wire tilt sensors are shipped with a clamp screw holding the internal
pendulum mechanism so that it is not damaged in shipment. A label is attached to
each sensor emphasizing the importance of removing the slotted-head clamp screw
completely and replacing it with the Phillips-head seal screw taped to the sensor.
(Extra seal screws are provided in a zip-lock bag along with other accessories in case
some become lost). This is very important for the sensor to be able to respond to
tilting and remain waterproof.
The sensor and wheel assembly is now attached to the first tube section using a single
long 10-32 cap screw. (Use Loctite 222 on all threads.)