Figure 4 - Another typical stress meter installation
Page 1: ...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 2003 2019 by Geokon Doc Rev G 05 1 19 ...
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Page 3: ...nnel 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 ...
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Page 5: ...ors 6 3 2 2 Operating the GK 405 6 3 3 GK 403 READOUT BOX OBSOLETE MODEL 7 3 3 1 Connecting Sensors 7 3 3 2 Operating the GK 403 7 3 4 MEASURING TEMPERATURES 7 6 DATA REDUCTION 8 6 1 STRESS CALCULATION 8 6 2 TEMPERATURE CORRECTION 9 7 TROUBLESHOOTING 10 APPENDIX A SPECIFICATIONS 11 A 1 4370 CONCRETE STRESSMETER 11 A 2 THERMISTOR 11 APPENDIX B THERMISTOR TEMPERATURE DERIVATION 12 APPENDIX C TYPICAL...
Page 6: ...NG PROTECTION SCHEME 4 FIGURE 6 LEMO CONNECTOR TO GK 404 5 FIGURE 7 LIVE READINGS RAW READINGS 6 FIGURE 8 TYPICAL CALIBRATION REPORT 13 TABLES TABLE 1 4370 SPECIFICATIONS 11 TABLE 2 THERMISTOR RESISTANCE VERSUS TEMPERATURE 12 EQUATIONS EQUATION 1 DIGITS TO CONCRETE STRESS LINEAR EQUATION 8 EQUATION 2 DIGITS TO CONCRETE STRESS POLYNOMIAL EQUATION 9 EQUATION 3 POLYNOMIAL GAUGE FACTOR C 9 EQUATION 4 ...
Page 7: ...own in Figure 1 Figure 1 The Model 4370 Concrete Stressmeter In essence the stressmeter comprises a short vibrating wire load cell in series with an 18 inch long cylinder of concrete This concrete cylinder has the same properties as the surrounding concrete but is de bonded from it by means of a smooth walled porous plastic tube and is coupled at its ends to the surrounding concrete by means of a ...
Page 8: ... 2 shows the far end of the stress meter is left open so that when the concrete is poured around the stressmeter the cell can be untied from the rebar and held vertical so that the same concrete can be packed inside the cell and then the end flange is pushed inside the end of the tube and securely taped in place It is of the utmost importance that there be no spaces left inside the cell so the con...
Page 9: ...Figure 4 Another typical stress meter installation ...
Page 10: ...o a terminal box or multiplexer components such as plasma surge arrestors spark gaps may be installed in the terminal box multiplexer to provide a measure of transient protection Terminal boxes and multiplexers available from Geokon provide locations for installation of these components Lighting arrestor boards and enclosures are available from Geokon that install at the exit point of the instrume...
Page 11: ...nsor conductors with blue representing the shield bare 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 b...
Page 12: ... into place Connecting sensors with bare leads Attach the GK 403 2 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 2 2 Operating the GK 405 Press the button labeled POWER ON A blue light will begin blinking signifying that the Remote Module is waiti...
Page 13: ...ion B 2 Turn the unit on 3 The readout will display the vibrating wire output in digits The last digit may change one or two digits while reading 4 The thermistor reading will be displayed above the gauge reading in degrees centigrade 5 Press the Store button to record the value displayed If the no reading displays or the reading is unstable see Section 7 for troubleshooting suggestions The unit w...
Page 14: ...nstallation just before the concrete is poured NOTE For greater accuracy use the regression zero found on the calibration report as R0 G is the linear gauge factor in MPa digit or psi digit taken from the calibration report The cross sectional area of the Stressmeter is equal to 5 31 sq in For example If Initial field zero reading 7035 digits Regression zero 7071 R1 5219 digits G 0 01748 MPa digit...
Page 15: ...are the polynomial gauge factors in MPa digit or psi digit taken from the calibration report For example If A 6 568E 07 MPa digit B 0 009799 MPa digit Initial field zero reading 7035 digits Current reading 5219 digits Then C 6 568E 07 7035 2 0 009799 7035 101 44 And the calculated concrete stress using S 6 658E 07 5219 2 0 009799 5219 101 44 32 41 MPa Compare these values to the actual applied str...
Page 16: ...way from the installation or install electronic filtering Make sure the shield drain wire is connected to ground whether using a portable readout or datalogger Does the readout work with another gauge If not the readout may have a low battery or be malfunctioning Symptom Strain gauge Fails to Read Is the cable cut or crushed This can be checked with an ohmmeter Nominal resistance between the two g...
Page 17: ...MPa to 25 Mpa Resolution 10 kPa Accuracy1 0 25 F S Temperature Range2 20 to 80 C Length Diameter 600 76 mm I D 66 mm Table 1 4370 Specifications Notes 1 Load cell accuracy 2 Other ranges available on request A 2 Thermistor See Appendix B also Range 80 to 150 C Accuracy 0 5 C ...
Page 18: ...3 107 9 123 77 66K 36 8006 4 1363 44 331 5 84 105 2 124 72 81K 35 7618 5 1310 45 321 2 85 102 5 125 68 30K 34 7252 6 1260 46 311 3 86 99 9 126 64 09K 33 6905 7 1212 47 301 7 87 97 3 127 60 17K 32 6576 8 1167 48 292 4 88 94 9 128 56 51K 31 6265 9 1123 49 283 5 89 92 5 129 53 10K 30 5971 10 1081 50 274 9 90 90 2 130 49 91K 29 5692 11 1040 51 266 6 91 87 9 131 46 94K 28 5427 12 1002 52 258 6 92 85 7 ...
Page 19: ...APPENDIX C TYPICAL CALIBRATION REPORT Figure 8 Typical Calibration Report ...
