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 © 2003-2016 by Geokon, Inc.
(Doc Rev K, 3/15/16)

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
Page
1. INTRODUCTION...................................................................................................................................................1
2. INITIAL SETUP.....................................................................................................................................................1
2.1 ACCESSORIES .......................................................................................................................................................1
2.2 ATTACHING TO A SENSOR ....................................................................................................................................2
3. OPERATION...........................................................................................................................................................2
3.1 POS (POSITION) SWITCH ................................................................................................................................3
3.2 MODE SWITCH .................................................................................................................................................3
3.3 CFG SWITCH .....................................................................................................................................................4
3.3.1BACKLIGHT:........................................................................................................................................4
3.3.2BATTERY VOLTAGE:...........................................................................................................................4
3.3.3CONTRAST:..........................................................................................................................................4
3.3.4AUTO-OFF:..........................................................................................................................................4
3.4 DEFAULT SETTINGS .......................................................................................................................................4
4. LOW BATTERY INDICATION AND AUTO-OFF............................................................................................5
5. MAINTENANCE ....................................................................................................................................................5
5.1 BATTERY REPLACEMENT .....................................................................................................................................5
5.2 CLEANING ............................................................................................................................................................5
5.3 CALIBRATION .......................................................................................................................................................5
6. TROUBLESHOOTING..........................................................................................................................................5
6.1 UNIT WILL NOT COME ON .....................................................................................................................................5
6.2 VIBRATING WIRE GAGE MEASUREMENT SHOWS DASHES ......................................................................................5
6.3 VIBRATING WIRE GAGE READING UNSTABLE ........................................................................................................6
6.4 THERMISTOR MEASUREMENT SHOWS DASHES ......................................................................................................6
6.5 DISPLAY SHOWS WEIRD CHARACTERS .................................................................................................................6
7. LIMITS OF LIABILITY........................................................................................................................................6
APPENDIX A - SPECIFICATIONS.........................................................................................................................7
A.1 VIBRATING WIRE READOUT:...............................................................................................................................7
A.2 TEMPERATURE READOUT:...................................................................................................................................7
A.3 PHYSICAL: ...........................................................................................................................................................7
APPENDIX B - CONNECTOR PIN OUTS..............................................................................................................7
B.1 TRANSDUCER PLUG PIN OUT ...............................................................................................................................7
APPENDIX C - THERMISTOR TEMPERATURE DERIVATION.....................................................................8

FIGURES
Page
FIGURE1.......................................................................................................................................................................1
FIGURE2,FIGURE3,FIGURE4......................................................................................................................................2
FIGURE5.......................................................................................................................................................................2
TABLES
Page
TABLE1–POSITIONSPECIFICATIONS...........................................................................................................................3
TABLE2‐TRANSDUCERPLUGPINOUT........................................................................................................................7
TABLE3‐RESISTANCEVERSUSTEMPERATURE............................................................................................................8

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 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 by pulling the Lemo connector out of the unit.
Figure 1
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). Next slide the connector all the way
to the right, then twist it clockwise until the bottom of the connector is pointing down (Figure 4).
Lastly, snap together the twin connectors located at the strap ends (Figure 5).

2
Figure 2 Figure 3 Figure 4
Figure 5
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.
2.2 Attaching to 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).
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 display:
GeokonInc.
GK-404 verX.XX
After approximately 1 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.

3
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 3.3.4) 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) SWITCH
Pressing the POS button will select the proper pluck settings for the vibrating wire gage that you
want to read.
Each Position setting (A-F) has different preprogrammed parameters that are optimized for
certain instruments. Each option also has different scaling and processing characteristics. See
the table below to determine the best choice for your sensors.
POS
Use with Geokon
Model No. MODE
Calculation
T = Period (1/F) in Sec
F = Frequency in Hertz
Units
Frequency
Sweep (Hz)
A All Dg
Hz
S
F210-3
F
T
Digits
Hertz
Sec
450-6000
B 4300BX, 4400,
4500, 4600, 4700,
4800, 4900
Dg
Hz
S
F210-3
F
T
Digits
Hertz
Sec
1500-3500
C 4000 E
Hz
S
F210-34.062
F
T

Strain ()
Hertz
Sec
450-1200
D 4200 E
Hz
S
F210-33.304
F
T

Strain ()
Hertz
Sec
450-1200
E 4100 E
Hz
S
F210-30.39102
F
T

Strain ()
Hertz
Sec
1500-3500
F 4300EX Dg
Hz
S
F210-3
F
T
Digits
Hertz
Sec
2500-6000
Table 1 – Position Specifications
3.2 MODE SWITCH
Pressing the MODE button will select the format of the vibrating wire reading. The available
options are: Dg (digits), Hz (hertz), S (period) and E (microstrain). Note: Only Positions C, D
& E support the E microstrain format.

4
3.3 CFG SWITCH
Pressing the CFG button will cause the GK-404 to enter the Configuration Menu. The
LCD screen will display:
GK-404 verX.XX
Config Menu
From this menu several GK-404 operating parameters may be set. Use the POS button to
select the various parameters and the MODE button to select each parameter’s options.
Press CFG twice at any time to exit the Configuration Menu and return to the Readings
Screen.
3.3.1 BACKLIGHT:
Press MODE to turn the LCD backlight ON or OFF.
3.3.2 BATTERY VOLTAGE:
This is a bar graph display of the power remaining in the (2) 1.5V AA cells, with Ffor
FULL and Efor EMPTY. The GK-404 is capable of continuous operation for greater
than 20 hours on a fresh set of batteries.
3.3.3 CONTRAST:
Press the MODE button to adjust the contrast of the LCD display in 10% increments.
3.3.4 AUTO-OFF:
Press the MODE button to select automatic shut-off after 5 minutes, 15 minutes or 30
minutes. You may also disable the Auto-Off timer so that the GK-404 will only shut off
if the front panel ON/OFF button is pressed. The Auto-Off will only activate if no front
panel buttons are pressed for the specified amount of time. The timer will reset each time
a button is pressed. When the GK-404 does shut off, all settings are saved to internal
memory and will restore the next time the GK-404 is turned on. (Note: The above
mentioned times are approximate.)
3.4 DEFAULT SETTINGS
Factory default settings may be restored at any time by pressing and holding the CFG and
POS buttons when turning the GK-404 ON. The factory default settings are:
POS B
MODE Dg
BACKLIGHT OFF
CONTRAST 50%
POWER-OFF TIME 5 minutes