Geokon 4450 User manual

Instruction Manual
Model 4450
VW Displacement Transducer
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 © 1994-2017 by Geokon, Inc.
(Doc Rev P 11/27/2017)

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...................................................................................................................................................7
1.1 THEORY OF OPERATION.......................................................................................................................................7
2. INSTALLATION ....................................................................................................................................................7
2.1 PRELIMINARY TESTS............................................................................................................................................7
2.2 DISPLACEMENT TRANSDUCER INSTALLATION.....................................................................................................8
2.3 SWAGELOK TUBE FITTING INSTRUCTIONS...........................................................................................................9
2.3.1 Installation..................................................................................................................................................9
2.3.2 Reassembly Instructions............................................................................................................................10
2.4 CABLE INSTALLATION AND SPLICING ................................................................................................................11
2.5 ELECTRICAL NOISE............................................................................................................................................11
2.6 LIGHTNING PROTECTION ...................................................................................................................................11
3. TAKING READINGS...........................................................................................................................................13
3.1 GK-404 READOUT BOX.....................................................................................................................................13
3.2 GK-405 READOUT BOX.....................................................................................................................................14
3.2.1 Connecting Sensors with 10-pin Bulkhead Connectors Attached.............................................................14
3.2.2 Sensors with Bare Leads...........................................................................................................................14
3.2.3 Operating the GK-405 ..............................................................................................................................14
3.3 GK-403 READOUT BOX (OBSOLETE MODEL)....................................................................................................15
3.3.1 Connecting Sensors with 10-pin Bulkhead Connectors Attached.............................................................15
3.3.2 Connecting Sensors with Bare Leads........................................................................................................15
3.3.3 Operating the GK-403 ..............................................................................................................................15
3.4 MEASURING TEMPERATURES.............................................................................................................................15
4. DATA REDUCTION ............................................................................................................................................16
4.1 DEFORMATION CALCULATION...........................................................................................................................16
4.2 TEMPERATURE CORRECTION.............................................................................................................................17
4.3 ENVIRONMENTAL FACTORS...............................................................................................................................18
5. TROUBLESHOOTING........................................................................................................................................20
APPENDIX A. THERMISTOR TEMPERATURE DERIVATION.....................................................................22
APPENDIX B. SPECIFICATIONS.........................................................................................................................23
B.1 MODEL 4450 DISPLACEMENT TRANSDUCER.....................................................................................................23
B.2 THERMISTOR (SEE APPENDIX AALSO)..............................................................................................................23
B.3 DIMENSIONS DRAWING FOR RANGES OF 50 MM (2”) AND BELOW ....................................................................24
B.4 DIMENSIONS DRAWING FOR RANGES OF 100 MM (4”) AND ABOVE...................................................................25

FIGURES
FIGURE 1-MODEL 4450 DISPLACEMENT TRANSDUCER................................................................................................ 7
FIGURE 2-TUBE INSERTION.......................................................................................................................................... 9
FIGURE 3-MAKE A MARK AT SIX O’CLOCK ................................................................................................................. 9
FIGURE 4-TIGHTEN ONE AND ONE-QUARTER TURNS .................................................................................................. 9
FIGURE 5-MARKS FOR REASSEMBLY ..........................................................................................................................10
FIGURE 6-FERRULES SEATED AGAINST FITTING BODY...............................................................................................10
FIGURE 7-TIGHTEN NUT SLIGHTLY.............................................................................................................................10
FIGURE 8-LIGHTNING PROTECTION SCHEME ..............................................................................................................12
FIGURE 9-LEMO CONNECTOR TO GK-404 ..................................................................................................................13
FIGURE 10 -LIVE READINGS –RAW READINGS............................................................................................................14
FIGURE 11 -ATYPICAL CALIBRATION SHEET..............................................................................................................19
FIGURE 12 -DIMENSIONS:RANGES OF 50 MM (2”) AND BELOW...................................................................................24
FIGURE 13 -DIMENSIONS:RANGES OF 100 MM (4”) AND ABOVE .................................................................................25
TABLES
TABLE 1-MODEL 4450 READING VERSUS POSITION IN THE RANGE ............................................................................. 8
TABLE 2-ENGINEERING UNITS CONVERSION MULTIPLIERS........................................................................................16
TABLE 3-THERMAL COEFFICIENT CALCULATION CONSTANTS ...................................................................................17
TABLE 4-SAMPLE RESISTANCE ...................................................................................................................................21
TABLE 5-RESISTANCE WORK SHEET...........................................................................................................................21
TABLE 6-THERMISTOR RESISTANCE VERSUS TEMPERATURE......................................................................................22
TABLE 7-MODEL 4450 DISPLACEMENT TRANSDUCER SPECIFICATIONS......................................................................23
EQUATIONS
EQUATION 1-DIGITS CALCULATION............................................................................................................................16
EQUATION 2-DISPLACEMENT CALCULATION..............................................................................................................16
EQUATION 3-THERMALLY CORRECTED DISPLACEMENT CALCULATION.....................................................................17
EQUATION 4-THERMAL COEFFICIENT CALCULATION .................................................................................................17
EQUATION 5-RESISTANCE TO TEMPERATURE .............................................................................................................22

7
1. INTRODUCTION
1.1 Theory of Operation
Geokon Model 4450 Vibrating Wire Displacement Transducers consist of a vibrating wire
sensing element, in series with a heat treated, stress relieved spring. One end of the spring is
connected to a vibrating wire, the other end to the transducer shaft. As the transducer shaft is
pulled out from the gage body, the spring is elongated, causing an increase in tension in the
vibrating wire. The increase in tension (strain) of the wire is directly proportional to the
extension of the shaft. This change in strain allows the Model 4450 to measure displacement
very accurately.
Model 4450 Displacement Transducers are fully sealed and can operate at pressures of up to 250
psi. They are designed to be read by one of the various readout boxes available from Geokon.
Figure 1 - Model 4450 Displacement Transducer
2. INSTALLATION
2.1 Preliminary Tests
CAUTION! Do not rotate the transducer shaft of the crackmeter more than 180 degrees.
This may cause irreparable damage to the instrument. The alignment pin on the
transducer shaft and slot on the body serve as a guide for alignment. Never extend the
crackmeter beyond its working range.
Before installing the gages in the field, perform a preliminary check by completing the following
1) Connect the gage to a readout box. (See Section 3 for information on using readout boxes.)
2) Take a reading. The reading should be stable and in the range of 4000 to 5000 digits.
3) To prevent damage during shipping, the transducer arrives with either a split PVC sleeve
taped to the body, or a metal dowel pin inserted into the shaft. Remove the PVC split sleeve
or dowel pin. When the shipping spacer is removed and the alignment pin is resting in the
alignment slot the reading should be in the range of 2000 to 3000.

8
4) A check of electrical continuity can be made using an ohmmeter. The resistance between the
two lead wires (usually red and black) should be around 180 ohms. Remember to add the
cable resistance at approximately 14.7Ω/1000' or 48.5Ω/km at 20 °C. Multiply this factor by
two to account for both directions.
5) Using an ohmmeter check the resistance between the two thermistor wires (usually white and
green). Using Table 6 in Appendix A, convert the resistance to temperature. Compare the
result to the current ambient temperature.
6) Resistance between any conductor and the shield should exceed two megohms.
2.2 Displacement Transducer Installation
1) Be sure to place the alignment pin of the transducer shaft into the alignment slot during
installation. This will prevent the internal wire from twisting.
2) With the #10-32 thread of the transducer shaft pressed against the shaft-mounting device,
rotate the transducer approximately 16 turns to tighten the transducer shaft onto the mounting
device.
3) Attach the red and black gage leads to the readout box. Select position B. (See Section 3 for
readout instructions.)
4) Gently pull on the transducer housing until the desired reading is obtained, see Table 1. Do
not extend the shaft further than the range of the gage! The transducer also may be
damaged if it is allowed to free fall through its stroke.
5) Hold the desired reading and secure the cable side of the gage against or inside the mounting
device. The transducer can be secured by using a Swagelok male connector with nylon front
and back ferrules. Tighten the Swagelok connector per the instructions in Section 2.3. Do not
rotate the gage tube relative to the shaft while securing!
6) Initial readings must be taken and carefully recorded along with the temperature at the time
of installation. These readings serve as a reference for subsequent deformation calculations.
Transducer Digit
Change
Minimum
Reading Maximum Reading Midrange
1/3
Compression
1/3 Extension
1/3 Extension
1/3 Compression
Standard 12,
25, and 50 mm
5,000 2000 7000 5000 6500 4000
Standard 100
and 150 mm
5,000 2000 7000 5000 6500 4000
Slim 12,
25, and 50 mm
10,000 3000 13000 8000 6000 9000
Table 1 - Model 4450 Reading versus Position in the Range

9
2.3 Swagelok Tube Fitting Instructions
These instructions apply to one inch (25 mm) and smaller fittings.
2.3.1 Installation
1) Fully insert the tube into the fitting until it bumps against the shoulder.
Figure 2 - Tube Insertion
2) Rotate the nut until it is finger-tight. (For high-pressure applications as well as high-
safety-factor systems, further tighten the nut until the tube will not turn by hand or
move axially in the fitting.)
3) Mark the nut at the six o’clock position.
Figure 3 - Make a Mark at Six O’clock
4) While holding the fitting body steady, tighten the nut one and one-quarter turns until
the mark is at the 9 o’clock position. (Note: For 1/16”, 1/8”, 3/16”, and 2, 3, and 4
mm fittings, tighten the nut three-quarters of a turn until the mark is at the 3 o’clock
position.)
Figure 4 - Tighten One and One-Quarter Turns

10
2.3.2 Reassembly Instructions
Swagelok tube fittings may be disassembled and reassembled many times.
Warning: Always depressurize the system before disassembling a Swagelok tube
fitting.
1) Prior to disassembly, mark the tube at the back of the nut, then make a line along the
nut and fitting body flats. These marks will be used during reassembly to ensure the
nut is returned to its current position.
Figure 5 - Marks for Reassembly
2) Disassemble the fitting.
3) Inspect the ferrules for damage and replace if necessary. If the ferrules are replaced
the connector should be treated as a new assembly. Refer to the section above for
installation instructions.
4) Reassemble the fitting by inserting the tube with preswaged ferrules into the fitting
until the front ferrule seats against the fitting body.
Figure 6 - Ferrules Seated Against Fitting Body
5) While holding the fitting body steady, rotate the nut with a wrench to the previous
position as indicated by the marks on the tube and the connector. At this point, there
will be a significant increase in resistance.
6) Tighten the nut slightly.
Figure 7 - Tighten Nut Slightly