Geokon GK-404 User manual

Instruction Manual
Model GK-404
Vibrating Wire Readout
No part of this instruction manual may be reproduced, by any means, without the written consent of Geokon, Inc.
The information contained herein is believed to be accurate and reliable. However, Geokon, Inc. assumes no responsibility for
errors, omissions, or misinterpretation. The information herein is subject to change without notification.
Copyright © 2003-2018 by Geokon, Inc.
(Doc Rev L, 1/25/18)

Warranty Statement
Geokon, Inc. 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, Inc. 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, Inc. or any breach of any warranty by Geokon, Inc. shall not exceed the
purchase price paid by the purchaser to Geokon, Inc. 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, Inc. 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
2. INITIAL SETUP .....................................................................................................................................................1
2.1 ACCESSORIES.......................................................................................................................................................1
2.2 CONNECTING A SENSOR.......................................................................................................................................2
2.3 CONNECTING A LOAD CELL.................................................................................................................................2
3. OPERATION...........................................................................................................................................................4
3.1 POS (POSITION)BUTTON ....................................................................................................................................4
3.2 MODE BUTTON ....................................................................................................................................................5
3.3 CFG (CONFIGURATION)BUTTON ........................................................................................................................5
3.4 DEFAULT SETTINGS.............................................................................................................................................5
4. LOW BATTERY INDICATION AND AUTO-OFF............................................................................................6
5. MAINTENANCE ....................................................................................................................................................6
5.1 BATTERY REPLACEMENT.....................................................................................................................................6
5.2 CLEANING............................................................................................................................................................6
5.3 CALIBRATION ......................................................................................................................................................6
6. TROUBLESHOOTING..........................................................................................................................................7
7. LIMITS OF LIABILITY........................................................................................................................................8
APPENDIX A. SPECIFICATIONS...........................................................................................................................9
A.1 VIBRATING WIRE READOUT ...............................................................................................................................9
A.2 TEMPERATURE READOUT ...................................................................................................................................9
A.3 PHYSICAL ...........................................................................................................................................................9
APPENDIX B. CONNECTOR PIN OUTS ...............................................................................................................9
B.1 TRANSDUCER PLUG PIN OUT ..............................................................................................................................9
APPENDIX C. THERMISTOR TEMPERATURE DERIVATION.....................................................................10

FIGURES
FIGURE 1-LEMO CONNECTOR ALIGNMENT .................................................................................................................. 1
FIGURE 2-NECK STRAP CONNECTOR ........................................................................................................................... 1
FIGURE 3-CONNECTOR ON GK-404 ............................................................................................................................. 1
FIGURE 4-CONNECTOR POINTING DOWNWARD ........................................................................................................... 2
FIGURE 5-NECK STRAP CONNECTIONS ........................................................................................................................ 2
TABLES
TABLE 1-LOAD CELL CONNECTOR AND CABLE (STANDARD WIRING) ........................................................................ 3
TABLE 2-POSITION SPECIFICATIONS ............................................................................................................................ 4
TABLE 3-TRANSDUCER PLUG PIN OUT ........................................................................................................................ 9
TABLE 4-THERMISTOR RESISTANCE VERSUS TEMPERATURE ......................................................................................10
EQUATIONS
EQUATION 1-RESISTANCE TO TEMPERATURE .............................................................................................................10

1
1. INTRODUCTION
The Model GK-404 Vibrating Wire Readout is a portable, low-power, handheld unit that is
capable of running for more than 20 hours continuously on two AA batteries. It is designed for
the readout of all Geokon vibrating wire gages and transducers, and is capable of displaying the
reading in either digits, frequency (Hz), period (µs), or microstrain (µε). The GK-404 also
displays the temperature of the transducer (embedded thermistor) with a resolution of 0.1 °C.
2. INITIAL SETUP
2.1 Accessories
The GK-404 is sold with the following accessories:
•GK-404-1 flying leads
•Carrying case
•Nylon strap for the carrying case
•Neck strap for the GK-404
Before use, attach the flying leads to the GK-404 by aligning the red circle on the silver “Lemo”
connector on the flying leads with the red line on the connector on the top of the GK-404. Insert
the Lemo connector into the GK-404 until it locks into place (Figure 1). Remove the flying leads
before storing the GK-404 in the carrying case.
Figure 1 - Lemo Connector Alignment
To install the nylon strap onto the carrying case, clip both ends of the strap onto the plastic loops
on the sides of the case.
To install the neck strap onto the GK-404, locate the plastic connector on the neck strap (Figure
2) and place the larger circular hole onto the plastic nub on the back of the GK-404, with the
bottom of the connector positioned to the right (Figure 3).
Figure 3 - Connector on GK-404
Figure 2 - Neck Strap Connector

2
Slide the connector all the way to the right, so that the nub on the back of the GK-404 locks into
the smaller hole of the connector. Turn the connector clockwise until the part of the bottom of
the connector is pointing down (Figure 4).
Figure 4 - Connector Pointing Downward
Lastly, snap together the twin connectors located at the strap ends (Figure 5).
Figure 5 - Neck Strap Connections
2.2 Connecting a Sensor
Attach the GK-404-1 flying leads to the bare leads of a Geokon vibrating wire sensor by
connecting each of the clips on the leads to the matching colors of the sensor conductors, with
blue representing the shield (bare).
Patch cables may be ordered from Geokon to enable sensors with connectors attached to the
readout cable to be read by the GK-404.
2.3 Connecting a Load Cell
Patch cables may be ordered from Geokon to enable load cells with connectors attached to the
readout cable to be read by GK-404.
If the load cell cable does not have a connector, the leads of the load cell may be connected to
the flying leads from the GK-404. The individual leads will be identified as shown in the wiring
diagram in Table 1. Each sensor is read in turn by clipping either the red or black clip to the lead
marked “common” and the black or red clip in turn to the leads marked #1, #2, #3, etc. The blue
clip should be connected to the cable shield and the green and white clips to the cable leads
marked “thermistor”.

3
10 pin Bulkhead
PT06A-12-10P
Function
3 Gage VW Load Cell
Geokon Purple Cable
4 Gage VW Load Cell
Geokon Purple Cable
6 Gage VW Load Cell
Geokon Orange Cable
A
Gage #1
Red
Red
Red
B
Gage #2
Red's Black
Red's Black
Red's Black
C
Gage #3
White
White
White
D
Gage #4
NC
White's Black
White's Black
E
Gage #5
NC
NC
Green
F
Gage #6
NC
NC
Green's Black
G
Shield
All Shields
All Shields
All Shields
H
Common
White's Black¹
Green
Blue
J
Thermistor
Green¹
Blue
Yellow
K
Thermistor
Green's Black
Blue's Black
Yellow's Black
Table 1 - Load Cell Connector and Cable (Standard Wiring)
Notes:
¹ White's black and Green wires are switched on Geokon three gage VW load cells prior to serial
number 3313.

4
3. OPERATION
To turn the GK-404 on, press the “ON/OFF” button on the front panel of the unit. The initial
startup screen will be displayed. After approximately one second, the GK-404 will start taking
readings and display them based on the settings of the POS and MODE buttons.
The unit display (from left to right) is as follows:
•The current Position (Set by the POS button) displayed as a letter, A through F.
•The current Reading, displayed as a numeric value, followed by the unit of measure (set by
the MODE button).
•Temperature reading of the attached gage in degrees Celsius.
The GK-404 will continue to take measurements and display readings until the unit is turned off,
either manually, or if enabled, by the Auto-Off timer. (See Section 3.3 for information on the
Auto-Off timer.) To turn the GK-404 off manually, press and hold the ON/OFF button until
Saving Settings is displayed then release. All user settings are stored on shut off and will be
restored the next time the GK-404 is turned on.
3.1 POS (Position) Button
The POS button is used to change the pluck settings of the GK-404. Each Position setting (A-F)
has different preprogrammed parameters that are optimized for certain instruments. Each option
also has different scaling and processing characteristics. Table 2 details the correct position to
use with the various models sold by Geokon.
Position
A
B
C
D
E
F
Use with Geokon
Model Numbers:
All
4300BX
4400 4500
4600 4700
4800 4900
4000 4200 4100 4300EX
MODE:
Dg
Hz
µS
Dg
Hz
µS
µE
Hz
µS
µE
Hz
µS
µE
Hz
µS
Dg
Hz
µS
Units:
Digits
Hertz
µSec
Digits
Hertz
µSec
µStrain (ε)
Hertz
µSec
µStrain (ε)
Hertz
µSec
µStrain (ε)
Hertz
µSec
Digits
Hertz
µSec
Calculation:
T = Period (1/F)
in
µ
Sec
F = Frequency in
Hertz
F2×10-3
F
T
F2×10-3
F
T
F2×10-3×4.062
F
T
F2×10-3×3.304
F
T
F2×10-3×0.39102
F
T
F2×10-3
F
T
Frequency
Sweep: (Hz)
450-6000 1500-3500 450-1200 450-1200 1500-3500 2500-6000
Table 2 - Position Specifications