TIGRE RESISTIVITY METER USER'S MANUAL
Contents
1. EMC 89 336 EEC Generic EN50081 1 Light Industrial Emissions EN50082 1 Light Industrial Immunity Tests Applied BSEN 55011 Class B Radiated Emissions BSEN 61000 4 4 Fast Burst Transients to Level 2 Light Industrial BSEN 61000 4 2 Static Discharge to Level 2 Light Industrial Category 3 PASS BSEN 55011 Class B Conducted Emissions N A battery only Low Voltage Directive 73 23 EEC N A below 50V AC Machinery Directive 98 37 EEC N A no moving parts We on behalf of Allied Associates Geophysical Ltd confirm the Product described above meets the requirement in all respects Alllied Associates Geophysical Ltd Concept House 8 The Townsend Centre Blackburn Road DUNSTABLE England LU5 5BQ Tel 44 0 1582 606 999 Fax 44 0 1582 606 991 e mail info allied associates co uk Associates PHY SICGAL L IMITED Tigre Manual Rev E 0506 Page 30 Allied Associates Geophysical Ltd Tigre Alllied Associates Geophysical Ltd USER MANUAL COMMENTS SHEET Please note on a copy of this form any suggestions for improvement or any errors found in this manual Please return the form to Graham White Alllied Associates Geophysical Ltd Concept House Blackburn Road DUNSTABLE Bedfordshire LU5 5BQ ENGLAND Manual Title Rev Number Comments Tigre Manual Rev E 0506 Page 312. J 1Eo Associates PHY SICAL L IMITED TIGRE RESISTIVITY METER USER S MANUAL Concept House 8 The Townsend Centre Blackburn Road Dunstable England LU5 5BQ Tel 44 0 1582 606 999 Fax 44 0 1582 606 991 e mail info allied associates co uk Allied Associates Geophysical Ltd Tigre WARRANTY 1 Allied Associates Geophysical Ltd AAGL products are fully tested in our workshop both during construction and after completion and are dispatched in full working condition Instruments are guaranteed for 12 months from the date of dispatch from the factory liability being limited in accordance with clause 9 of the General Conditions for the Supply of Plant and Machinery for Export UN Economic Commission for Europe Geneva 1953 2 When unpacking please check the contents against the packing list and inspect for damage and malfunction of any kind In the case of any defect inform the carrier immediately and report in full to AAGL or their local agent the extent of the damage Await their reply before taking any further action except in exceptional circumstances 3 Should a fault be identified that cannot be remedied on site within the guaranteed period consult with AAGL Normal procedure will be to return the unit or complete system if necessary carriage paid to AAGL for inspection and repair or replacement free of charge provided the fault has not been due to misuse 4 As far as possible use original
3. Allied Associates Geophysical Ltd Tigre mA CURRENT The button marked mA is used to select the desired current in milli amps The current is increased each time the button is pressed in the following steps MODE The button marked MODE selects the type of measurement The display will indicate the following sequence of options as appropriate Resistance Self potential Battery Volts NUMBER OF CYCLES The button marked CYCLES selects the number of readings to be averaged This can be from 1 to 16 Details of how the signal is processed to obtain a single measurement of ground resistance are given in Section 2 4 of this manual SAMPLE TIME If the MODE and mA buttons are pressed simultaneously the sample time or signal length can be changed as shown below Tigre Manual Rev E 0506 Page 12 Allied Associates Geophysical Ltd Tigre APLHA NUMERIC DISPLAY The 80 character 4x20 liquid crystal display indicates the parameters selected and the measurement details as the survey progresses See Fig 3 The display can be backlit by pressing MODE and CYCLES simultaneously The light automatically switches off after one minute if no activity is sensed during this time J z pag i _ i he j L mo B He i of y a 3 _ b b Fig 3 TIGRE Display and Electrode Terminals EXTERNAL POWER SUPPLY An external 12V power supply may be connected through the socket situated immediately b
4. Tigre Manual Rev E 0506 Page 8 Allied Associates Geophysical Ltd Tigre Offset Wenner Sounding Electronically controlled switching in the module enables high quality soundings to be measured automatically using the patent OFFSET SOUNDING SYSTEM Offset Wenner Schlumberger or Wenner soundings may be easily carried out using the appropriate manual swithching unit and corresponding cables Electrical Imaging The TIGRE can also be used with multicore imaging cables with any electrode spacing Normal operational spacings are either Im 2m 5m or 10m The software carries out repeated sweeps along with a constant separation 2 3 or 4 electrode array increasing the spacing at each sweep thus producing an electrical cross section pseudosection or image of the ground that can be further refined by processing This is particularly applicable to environmental and engineering site investigations and for archaeological studies Depending on the amount of switching included in the Tigre from 1 to 4 cables can be connected directly to the instrument 1 4 POWER BOOSTER Starting in July 1999 the power booster is fitted as standard to all Tigre systems providing current capacity to 200mA Tigre Manual Rev E 0506 Page 9 Allied Associates Geophysical Ltd Tigre THE TIGRE 2 1 CONSTRUCTION MODE A CYCL CE Serial No O15 Fig 1 The Tigre front panel The TIGRE is housed in an impact resistant steel case with removabl
5. 0 6 5 0 7 5 0 KA HR HR HW W 5m cable Level Current Cycles 1 2 0 2 5 0 3 5 0 4 5 0 5 5 0 6 10 0 7 10 0 4 In low resistivity conditions the current should be increased further Check the waveform to make sure that a good voltage signal is being detected fA DB HA DA A In noisy conditions either the current on time or the number of cycles should be increased 3 7 SURVEY MODES Traverse There are two survey modes that can be employed Traverse mode allows the completion of all measurements with n 1 before commencing with the n 2 measurements and so on With a 32 electrode cable a complete pseudosection measured in traverse mode will comprise the following number of measurements at each level Level Electrode spacing Number of measure ments a 22 2 2a 19 3 3a 16 4 4a 13 5 5a 10 6 6a 7 7 7a 4 Tigre Manual Rev E 0506 Page 25 Allied Associates Geophysical Ltd Tigre Traverse mode measurements are shown in Fig 8 Station 4 mie Cz Laptop Station 3 C P P C mere pil Station 2 C P P C o Station 1 C P P C 32 Electrodes n 1 n 2 n 3 O00 00000 00 0 0 n 4 SoG OG CoG Go Go OG n 5 000 00 O O 0 Fig 8 Principle of electrical imaging with a multicore cable in traverse mode Roll on Roll on mode takes measurements for n 1 2 3 4 5 and 6 for station 1 before continuing in the same way for station 2 Fig 9 This type of survey should be used if the survey line is likely
6. Associates Geophysical Ltd Tigre Select Option 1 OPTION 1 When Option 1 is selected the following menu appears Enter parameter filename use no spaces prm Enter the filename of the previously created parameter file The filename should be no more than 8 characters long The file extension PRM is provided by the computer automatically OPTION 2 Select this option to view the data in the parameter file The following type of information will be displayed Test Survey Reading Current Cycles Ten Toh P1 P2 Gal Ga J HO 2 1g 9 Op 5 1 2 3 4 2 149 2 4 9 Q5 2 3 4 5 3 HO 2 4 9 EE 3 4 E 6 4 4O 2 lg Q Qe 5 4 5 6 A 5 49 2 4 9 Oe 5 E 6 A 8 6 4O 2 iy 9 Oe amp 6 4 8 9 Press any key to continue OPTION 3 Select this option if further editing is required Screen messages are as described in Option 1 OPTION 4 Select this option to start a survey using the parameters described in the parameter file The following message appears File filename PRM allows 6 different measurements Select option All measurements Ji Selected range 2 Comitini MUFI E Tigre Manual Rev E 0506 Page 22 Allied Associates Geophysical Ltd Tigre If only a selected range is required the program will ask for Number of finge measmaememin Number of last measurement Sub option 3 above can be used after a set of resistance measurements has been interrupted where the user has had to return t
7. Controls and Connections 11 2 2 1 ON OFF Switch 11 222 GO button 11 2 2 3 mA current button 11 2 2 4 MODE button 12 2 2 5 Number of Cycles 12 2 2 6 Sample Time 12 2 2 7 Alpha Numeric Display 13 2 2 8 External Power Supply 13 2 2 9 Computer Control 14 2 2 10 Manual Control 14 2 2 11 External System Connection 14 23 Making Measurements 15 2 4 The Signal 17 2 5 Power Supply 18 2 6 Battery Charger 18 Tigre Manual Rev E 0506 Page 6 Allied Associates Geophysical Ltd Tigre 3 ELECTRICAL IMAGING WITH IMAGER CABLES 19 3 1 Introduction 19 3 2 The system 19 3 3 Choice of Cable 19 3 4 Laying Out the Cables and Electrodes 20 3 5 Designing and Carrying Out a Survey with TIGREPRM and TIGRECOM Control Software 21 3 6 Instrument Parameters 24 3 7 Survey Modes 25 3 8 Problems 27 3 9 Presentation of Data 27 4 TIGRE SPECIFICATIONS 28 D EC CERTIFICATES OF CONFORMITY 29 30 Tigre Manual Rev E 0506 Page 7 Allied Associates Geophysical Ltd Tigre GENERAL DESCRIPTION OF THE SYSTEM 1 1 THE TIGRE The TIGRE is a high quality earth resistance meter capable of accurate measurement over a wide range of conditions lt has a maximum power output of 18 watts manual selection of current in steps up to 200mA a choice of sample time signal length averaged and three frequency settings The receiver incorporates automatic gain steps which provide a range of measurements from 0 001Q to 360kQ The instrument is powered by a large c
8. due to sudden increases in ground noise saturating the system If the area is generally very noisy it may be necessary to operate at the longest cycling time In extreme conditions i e measuring very low resistances against a background of large amplitude and varying SP highly inconsistent readings may be obtained In this case it is necessary to put the instrument into the computer command mode and vary the sampling parameters until satisfactory results are obtained See Section 3 2 5 POWER SUPPLY The Tigre uses sealed gel cell batteries 7 AH at 12V Under average working conditions e g 10 offset soundings per day at 5mA recharging every 2 working days would be Safe practice Electrical imaging uses more drain on the batteries and so the instrument should be charged overnight during survey operations Should it be necessary to be away from an AC power source for more than a few days the instrument can be operated using an external supply A 12V car battery which can be recharged from a vehicle can be used in an emergency A separate lead is supplied which can be clipped onto the battery Be sure to check the polarity before connecting to the instrument Do not run the vehicle engine while the instrument is connected to the battery as transients from the alternator can damage the transmitter circuitry 2 6 BATTERY CHARGER This operates from 240V or 115V AC The maximum current output is such that batteries can be left on ind
9. software has been tested under a variety of field conditions but inevitably problems will occur when it is used in different environments It is hoped that these problems will be minor If you experience problems or have comments on the use of TIGIMG please contact Allied Associates Geophysical Ltd 3 9 PRESENTATION OF DATA The observed data can be plotted as a conventional pseudosection An approximate depth scale may be provided using the following guide n a 2 n Gl 2 3a 2 when 23 depth 3 n 5a 2 n 6 3a The pseudosection can be contoured and viewed as an approximate image of the subsurface An automatic inversion program RES2DINV is available and enables coloured images of the ground to be produced automatically Alternatively it can be modelled using a forward modelling program such as RESIXIP2D also available from Allied Tigre Manual Rev E 0506 Page 27 Allied Associates Geophysical Ltd Tigre TIGRE SPECIFICATIONS TRANSMITTER Maximum power output Current range Square wave repetition Number of readings averaged RECEIVER Input voltage range Input impedance Measurement range Low pass filter Display Power supply GENERAL Weight Electrode capacity 18W 0 5mA to 200mA 8 45 4 25 2 85 1 to 16 O 180V with auto gain averaging 22MQ 360KQ 0 0010 80 character alphanumeric liquid crystal Rechargeable sealed lead acid 7 AH 12V 6kg 32 to 128 opti
10. apacity rechargeable battery providing several days of use without recharging in average terrain conditions The TIGRE is housed in an impact resistant steel case 1 2 COMPUTER CONTROL Though the TIGRE can be used as a Stand alone system to carry out electrical profiling or vertical soundings with any type of electrode array it has been designed with a view to integrating it with a number of resistivity survey systems developed by AAGL To make this possible control of the instrument is transferred to a portable notebook computer IBM compatible The computer automatically switches in the correct electrodes for each particular measurement through a bank of relays housed in the meter Computer control also has the advantage of making possible a much wider range of instrument parameters than would otherwise be practicable The square wave reversal periodicity and the current on to current off ratio can both be modified in order to optimise measurement quality All data are logged and are immediately available for interpretation Self potential readings can also be monitored and there are a number of check routines Basic DOS software TIGIMG and PRM64_2 for operating the computer can be supplied on request 1 3 THE SURVEY SYSTEM The construction of the TIGRE with its own switching capabilities makes it easy to operate with a variety of survey systems These can only be operated when the instrument is functioning under computer control
11. case and packaging material for return of the instrument Equipment is on occasions subject to very rough handling during transit and AAGL cannot be liable for damage due to faulty packing 5 It is the responsibility of the customer to notify AAGL or their agent of defect or damage to the equipment within a reasonable time of receipt We would recommend that any defect or omission should be notified verbally but with written confirmation no more than 72 hours after receipt of the product 6 AAGL Associates Geophysical Ltd will take all necessary steps to rectify any failure which is deemed the responsibility of the manufacturer as quickly as possible 7 No liability against consequential loss can be accepted under any conditions Thank you for purchasing the Tigre Resistivity Meter Allied Associates Geophysical Ltd Concept House 8 The Townsend Centre Blackburn Road Dunstable England LU5 5BQ Tel 44 0 1582 606 999 Fax 44 0 1582 606 991 e mail info allied associates co uk Attn Graham White Technical enquiries Attn Norman Bell Sales enquiries Tigre Manual Rev E 0506 Page 2 Allied Associates Geophysical Ltd Ssreaeceeseszegeries esSeezrregzrseressserss eee LL n o on o on Se Campus International Products Ltd arene Tot tunai Setar 008 meters 2D Resistivity Imaging Survey A ai Modeled True Resistivity Tigre 128 with ImagerPro 2000XL Data courtesy of Geo Service
12. ce the signal shown in Fig 6 a mA a Volts b Time Fig 6 The TIGRE SIGNAL a Transmitted signal variable Periodicity b Received signal Here the attenuated and modified signal is superimposed on slowly varying earth currents It is sampled over times A B and C The on period is sampled for only the last 4 5 of the on time e g 0 8s in 1 0s An example of the received signal in the presence of electrical ground noise is shown in Fig 6 b This figure also illustrates the processing technique used to extract a value of the required potential difference from the received signal here shown superimposed on a slowly varying earth current The signal is digitally sampled over times A B and C and the amplitude calculated as Va Vc 2Vb 4 The on off ratio is 2 5 1 and the sample unsampled ratio during any ON period is 4 1 This is to allow any coupling and IP affects to die away before sampling takes place Tigre Manual Rev E 0506 Page 17 Allied Associates Geophysical Ltd Tigre When a number of cycles are averaged the microprocessor calculates the potential difference from successive sets of three ON periods ABC BCD CDE giving values Va Vc 2Vb 4 Vb Vd 2Vc 4 etc When conditions are adverse i e a low signal ground noise ratio apparent as a lack of consistency in the readings use higher current settings that do not cause a GAIN ERROR and average over 16 cycles Gain errors are usually
13. e a 2 to 4a For example a 1 meter spacing would be used to study the range 0 5 to 4m A SINGLE CABLE WITH TIGRE 32 64 1 Electrodes 32 B TWO CABLES WITH TIGRE 64 1 Electrodes Cable 1 32 33 Electrodes Cable 2 64 C TWO CABLES WITH TIGRE 128 1 Electrodes Cable 1 32 33 Electrodes Cable 2 64 Extension Cable D FOUR CABLES WITH TIGRE 128 Cable 1 1 Electrodes Cable 1 32 33 Electrodes Cable 2 64 65 Electrodes Cable 3 96 97 Electrodes Cable 4 128 Extension Cable Extension Cable Fig 7 Electrode connections Tigre Manual Rev E 0506 Page 20 Allied Associates Geophysical Ltd Tigre 3 4 LAYING OUT THE CABLES AND ELECTRODES The IMAGER cables are set out in a straight line and electrodes connected to every takeout The electrodes should be inserted into the ground to a depth of no more than 5 of the unit electrode spacing For small spacing cables special small electrodes are supplied so that the operator is not tempted to plant electrodes to greater depths Nevertheless the operator should ensure that good ground contact is achieved In dry conditions each electrode should be withdrawn and a small amount of water added to the hole before replanting the electrode When all the electrodes have been connected the system is ready to run the program TIGRECON 3 5 DESIGNING AND CARRYING OUT A SURVEY WITH TIGIMG AND PRM64_2 CONTROL SOFTWARE N OT E the following instructio
14. e lid and is fully water resistant The various units are mounted below the front panel and the whole instrument can be removed from the case by unscrewing the plate The transmitter receiver controls and display occupy the left hand half of the panel while client selected cable sockets are located on the right hand half of the panel The design of the TIGRE allows for the construction of a basic resistivity meter or a multi electrode imaging system up to 128 electrodes The design concept also allows for straightforward upgrade from 32 electrodes to 128 in modular steps thus allowing the system to expand in line with customer requirements Tigre Manual Rev E 0506 Page 10 Allied Associates Geophysical Ltd Tigre 2 2 THE CONTROLS AND CONNECTORS eeo Q MODE mA CYCLES P ON OFF a an Fig 2 TIGRE Lower Left Hand front panel showing Operation Buttons All the external controls together with the liquid crystal display are situated on the top front panel of the instrument They are fully waterproof The controls are shown in Fig 2 and are described below In addition to the ON switch and the GO or initiate measurement button there are three other buttons marked mA MODE and CYCLES See Fig 3 ON OFF Select to switch the instrument for operation or to switch the instrument off GO Press this button to initiate measuring with the previously set parameters Tigre Manual Rev E 0506 Page 11
15. efinitely without suffering and damage Charging time from full discharge is 16 hours If storing the Tigre for a long period of time recharge the battery every month Failure to do so will result in irreversible damage to the battery neceessating it s replacement NOTE it the meter is operated while the battery is being charged the charger is automatically disconnected Tigre Manual Rev E 0506 Page 18 Allied Associates Geophysical Ltd Tigre ELECTRICAL IMAGING WITH THE TIGRE 3 1 INTRODUCTION The Allied TIGRE contains a switching module which enables automatic addressing of multi electrode survey systems The minimum configuration allows for the switching of up to 32 electrodes Additional onboard modules will allow for 64 and 128 electrodes Using the DOS based TIGIMG program and PRM64_2 then each survey electrode may be addressed and set up as either one of the current electrodes Cl or C2 or one of the potential electrodes P1 or P2 An electrode may be addressed to take two roles so that for example it can act as both Cl and P1 Additionally far electrodes may also be connected directly to the Tigre resistance meter The system therefore has complete versatility If using Windows please see ImagerPRO section at the back of the manual 3 2 THESYSTEM The IMAGER cables should be connected to the TIGRE at the sockets marked CABLE 1 CABLE 2 etc A portable Laptop computer is connected to the RS232 port The relation
16. elow the RS232 socket See Fig 5 A connecting lead is supplied for this purpose It is important to remember the correct polarity when connecting to an external supply n Do not connect to a car battery while itis being charged Tigre Manual Rev E 0506 Page 13 Allied Associates Geophysical Ltd Tigre COMPUTER CONTROL To operate under computer control connect any IBM compatible notebook computer to the resistivity meter via the RS232 port See Fig 5 A connecting lead is supplied The correct connections to the instrument are shown below Fig 4 Ground Fig 4 RS232 port connections MANUAL CONTROL The red and black coloured current and potential terminals marked P1 P2 Cl C2 are situated on the front panel See Fig 3 Single core cables may be connected to these terminals for measuring earth resistance Fig 5 TIGRE Display and Electrode Terminals Tigre Manual Rev E 0506 Page 14 Allied Associates Geophysical Ltd Tigre 2 3 MAKING MEASUREMENTS K OT E the following instructions are for use with DOS programs TIGIMG and PRM64_ 2 only For Windows based operation see ImagerPRO section at the end of the manual 1 Check that the instrument is correctly connected to the current and potential cables See Fig 7 When the manual Offset Wenner system is used the current and potential terminals are connected to the Offset Wenner system switchbox See separate manual supplied with the Of
17. erally not a problem if multicore cables are being used as the TIGRE has a very high input impedance However one effect of high electrode contact resistance when multicore cables are used is an increase in coupling between cores and consequent distortion of the observed waveform This can be quite severe in laboratory experiments where the measuring system itself can add to the distortion of the waveform In field surveys our experience suggests that good data can be recorded if contact resistances are lowered to less than 200Q This is done by watering electrodes with saline water emplacing them in clay or using multiple electrodes 3 6 INSTRUMENT PARAMETERS The suggested values below have been selected to produce measurements with the minimum of power The operator can increase the speed of the survey by reducing the current on time to 1 second or less If this is done it is likely that the current will have to be increased to 1 2 or 5 mA depending on the electrode spacing used If unstable measurements are obtained the current should be increased Currents of more than 100 mA should not normally be employed with IMAGER cables Example settings for 1m 2m and 5m cables might be as follows m cable Level Current Cycles 0 5 3 2 1 0 3 3 1 0 3 4 1 0 4 5 1 0 4 6 2 0 4 ii 2 0 4 Tigre Manual Rev E 0506 Page 24 Allied Associates Geophysical Ltd Tigre 2m cable Level Current Cycles 1 0 2 2 0 3 2 0 4 2 0 5 2
18. fset Wenner Sounding System 2 Switch on Display shows MODE Resistance b 0 5m yelga 3 Check battery volts If the battery is below the operating voltage the display will read BATTERY LOW Reduce Current 4 Take care to keep operating temperature within the specified range Check the temperature regularly because in tropical sunshine it may well rise above the danger level Note that although the instrument will operate below 0 C it is not designed for work under exceptionally low temperature conditions 5 Check the SP voltage Use the MODE switch to put the instrument into the Self Potential mode Make a few measurements to see how it is varying by pressing the GO switch and noting the results obtained The amplitude and rate of change of the SP will affect the readings at low resistance values and determine the instrument settings required to optimise accuracy 6 Select the current setting using the mA button Normally start at 2mA and keep as low as possible consistent with obtaining good repetition If ground conditions are such that the instrument cannot deliver the required current or there is an open circuit it will read CURRENT ERROR Check Electrodes Tigre Manual Rev E 0506 Page 15 Allied Associates Geophysical Ltd Tigre Decrease the current and or water the electrodes to improve ground contact Experience shows that when operating multicore cable systems accurate measurements are obtained with contac
19. ns are for use with DOS programs TIGIMG and PRM64 2 only For Windows based operation see ImagerPRO section at the end of the manual The system may be set up to operate routinely with any particular set of electrodes and cables to carry out specific survey measurements The survey design is stored ina parameter file which once created can be accessed by the control software whenever needed However the parameter file has to be created when the survey is first run A fast method of setting up parameter files for the measurement of Wenner pseudosections is included as a separate program PRM64_2 EXE The parameter file should be created before running TIGIMG Parameter files for other types of survey are best created using EXCEL or other software Once in the field ready to start measurements the laptop computer is switched on and the system booted Run TIGIMG and follow the instructions After the title screen the correct serial port COM1 or COM2 must be selected The following main menu then appears KaKAKKKKKKKKKEKEKETTGRECON MAIN MENU RX Please enter option Load Create parameter file 1 Viu BS ec il oeae ae 2 Edits pananghega fille e 3 Take continue resistance measurement 4 Show resistance measurements 5 Save resistance measurements 6 Repeat Oe BAe al eee 7 Check GOMGA Ci Geese ee ee 8 Epei Bo Ske e eee ee ee r 9 Tigre Manual Rev E 0506 Page 21 Allied
20. o the main menu to edit a parameter file for example The computer then prints a message instructing the operator to SWITCH ON METER SWITCH ON METER SWITCH ON METER SWITCH ON METER SWITCH ON METER SWITCH ON METER The computer then completes a set of resistance measurements displaying the results as they are obtained OPTION 5 The resistances may be examined using this option If it is necessary to repeat a measurement the operator should proceed to Option 7 OPTION 6 Select this option to store data on disk A filename for data storage has to be supplied OPTION 7 To repeat a measurement the number of the measurement as it appears in the parameter file has to be entered Tigre Manual Rev E 0506 Page 23 Allied Associates Geophysical Ltd Tigre OPTION 8 The software provides the possibility of estimating electrode contact resistances This is done by first measuring resistances at 3 electrodes at which good ground contact is certain By default the TIGRE selects the first closest three electrodes on Cable 1 Assuming no cable resistance and negligible ground resistance a set of simultaneous equations is solved to provide contact resistances at the first three electrodes All other contact resistances are measured in relation to electrode 1 For this reason it is important that electrode 1 is correctly connected Contact resistances will be displayed as they are measured High contact resistances are gen
21. onal Link to portable IBM compatible PC provides 1 Wide choice of waveform and frequency 2 Choice of sampling interval 3 Display of received waveform 4 Data logging Tigre Manual Rev E 0506 Page 28 Allied Associates Geophysical Ltd Tigre CERTIFICATE OF CONFORMITY Product Charger for TIGRE earth resistance meter Serial NO _cacaaumaesisonubivenoenidaennecas Date of Shipment 008 EMC 89 336 EEC Generic EN50081 1 Light Industrial Emissions EN50082 1 Light Industrial Immunity Tests Applied BSEN 55011 Class B Conducted Emissions BSEN 55011 Class B Radiated Emissions BSEN 61000 4 4 Fast Burst Transients to Level 2 Light Industrial BSEN 61000 4 2 Static Discharge to Level 2 Light Industrial Category 1 PASS Low Voltage Directive 73 23 EEC N A below 50V AC Machinery Directive 98 37 EEC N A no moving parts We on behalf of Allied Associates Geophysical Ltd confirm the Product described above meets the requirement in all respects Alllied Associates Geophysical Ltd Concept House 8 The Townsend Centre Blackburn Road DUNSTABLE England LU5 5BQ Tel 44 0 1582 606 999 Fax 44 0 1582 606 991 e mail info allied associates co uk Associates P H YSICAL L IMITED Tigre Manual Rev E 0506 Page 29 Allied Associates Geophysical Ltd Tigre CERTIFICATE OF CONFORMITY Product TIGRE earth resistance meter Serial NO cceecccececesecceeeeees Date of Shipment
22. s International UK Lid t Example of Tigre data Tigre Manual Rev E 0506 Page 3 Allied Associates Geophysical Ltd Tigre Copyright 2006 Allied Associates Geophysical Ltd All rights reserved including the right of reproduction in whole or in part in any form Published by Allied Associates Geophysical Ltd Concept House 8 The Townsend Centre Blackburn Road DUNSTABLE Bedfordshire England LU5 5BQ Printed in Great Britain Tigre is a registered trademark of Allied Associates Geophysical Ltd Tigre Manual Rev E 0506 Page 4 Allied Associates Geophysical Ltd Tigre INTRODUCTION THE ALLIED TIGRE RESISTIVITY METER The Allied TIGRE is a high quality earth resistance meter capable of accurate measurements over a wide range of conditions To enhance its capabilities it is provided with an RS232 computer link enabling control to be transferred to a PC notebook computer The TIGRE incorporates banks of relays which will allow computer controlled sounding and imaging Tigre Manual Rev E 0506 Page 5 Allied Associates Geophysical Ltd Tigre CONTENTS WARRANTY 2 INTRODUCTION 4 CONTENTS 5 6 GENERAL DESCRIPTION OF THE TIGRE RESISTIVITY SYSTEM 8 1 1 The TIGRE 8 1 2 Computer Control 8 1 3 The Survey Systems 8 1 3 1 Profile and Mapping 9 1 3 2 Offset Wenner Sounding 9 1 3 3 Electrical Imaging 9 1 3 4 MRT Surveys 9 1 4 Power Booster 9 2 THE TIGRE INSTRUMENT 10 2 Construction 10 2 2 The
23. ships of the electrodes to the relays in the control module are shown in Fig 7 The following description assumes that standard 32 takeout cables are employed in the surveys A A single IMAGER cable If a single IMAGER cable is being used it should be connected to the socket marked CABLE 1 In this case relays 1 32 will correspond to the electrodes 1 32 numbered from the connector See Fig 7 A This is true for 32 and 62 channel systems B Two IMAGER cables When two cables are connected to the control instrument the electrodes will normally be numbered from one end of the line of 64 electrodes to the other end In this case relay 32 will correspond to electrode 1 and relay 1 to electrode 32 On the second cable relay 33 will correspond to electrode 33 and so on to relay 64 which will correspond to electrode 64 Full details are shown in Fig 7 B This is true for 32 and 62 channel systems C Two IMAGER cables with Tigre 128 See Fig 7 C for cable deployment method using an extension cable D Four IMAGER cables with Tigre 128 See Fig 7 D Tigre Manual Rev E 0506 Page 19 Allied Associates Geophysical Ltd Tigre 3 3 CHOICE OF CABLE Select a cable with electrode spacing suitable for the problem being studied If measure ments are made with multiples n of the unit electrode spacing a from n 1 ton 8 the depth range covered is approximately from a 3 to 6a although the greatest response will be from the depth rang
24. t resistances below 2000Q 7 Select the number of readings to be averaged using the CYCLE button This will depend to a great extent on ground noise Start with 4 readings and increase or decrease depending on the consistency of the readings obtained 8 Select Resistance and press the GO button The display will initially indicate the voltage gain being used in the measurement Setting Gain GS Anes ito G indicates the amplifier gain setting These are x5 x0 5 x0 05 and x0 005 In a noisy environment high and varying SP values may cause the amplifier to saturate during the averaging The display will show GAIN ERROR Change Cuss3e In this case reduce the current to bring the signal within the operating range The display will then indicate the successive averages of the resistance bleeping each time during the process At the standard setting the instrument takes 2 15 to complete a set of 4 readings A three figure resistance will show with the decimal point approximately placed followed by Q or mQ If the potential and current connections have been incorrectly connected a negative sign will precede the digits This can also be due to ground conditions 9 If the switching circuits operated by the current or mode buttons on the top panel are faulty the display will read MODE ERROR Tigre Manual Rev E 0506 Page 16 Allied Associates Geophysical Ltd Tigre 2 4 THE SIGNAL The transmitter uses commutated DC to produ
25. to extend to more than 32 electrodes The operator can stipulate the number of measurements which are made before the cable is moved and the process repeated There are many ways such a Survey can be carried out but the following technique will provide continuous cover at Level 7 quickly and efficiently 1 The cable is set out and measurements are made in Roll on mode for 7 stations The table above shows that this is the maximum number of measurements possible at Level 6 with 32 electrodes deployed Be sure to record the data before progressing 2 The cable is disconnected and moved along the line until takeout 1 arrives at electrode 8 The 7 used electrodes are moved to the forward end of the line so that 32 electrodes are again connected 3 The TIGIMG survey program is continued in Roll on mode for a further 7 stations The measured data are appended to the end of the data file created in step 1 4 The process is repeated until the final cable position is reached 5 At the end of each roll on stage a message is displayed Tigre Manual Rev E 0506 Page 26 Allied Associates Geophysical Ltd Tigre Laptop Tigre computer Station3 P P C Station 2 Station 1 n 1 ooeoece oO G66 6 6 6G 6 oO 1 n 2 eo coco obdo oo 8 ee O 2 n 3 coc ooco ooo ooo O 3 n 4 oOo oO OO OO OO O O O O 4 n 5 o o O O O O O Fig 9 Principle of electrical imaging in roll on mode 3 8 PROBLEMS This version of TIGIMG control
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