APPLICATIONNOTE Usingthe3D …

1 3D RotatorAPPLICATION NOTEU sing the 3D-Rotator with MultifunctionKappabridge MFK11 IntroductionNew 3D-Rotator ( ) was developed by AGICO company to increasethe speed and comfort of anisotropy of magnetic susceptibility (AMS)measurements. The 3D-Rotator rotates the specimen simultaneouslyabout two axes with different velocities. The 2-axis rotation enablesto determine 320 directional susceptibilities during a single anisotropymeasurement. These directions are very well distributed on a spherewhich makes the measuring design almost rotatable. Calculation ofthe anisotropy tensor and respective error analysis is based on the prin-ciples described by Jelinek (1977) actual measurement is fully automated in such a way that, oncethe specimen is mounted into the rotator, it requires no additional ma-nipulation to measure the full AMS tensor.

2 The approximate durationof one anisotropy measurement including bulk susceptibility is ,compared to more than 3 minutes when the classical (3-plane) rotatoris 1: New 3D-Rotator for Agico Multifunction Kappabridges1 The Statistical Theory of Measuring Anisotropy of Magnetic Susceptibility of Rocks andIts Interpretation. This publication can be downloaded the section Customers Support/User manuals and AGICO notepage 13D Rotator2 RequirementsThe3D-Rotatoriscompatiblewit hAgicoKappabridgesinversionsMFK1-A and MFK1-FA. The Electronic Unit must be equipped with the latestprocessor (release date 12-12-2012). The measurement with 3D-Rotatoris controlled by new Safyr5 software. Both the processor and the soft-ware are supplied together with the 3D-Rotator. Instructions for ex-changing the processor inside the MFK Electronic Unit are notepage 23D Rotator3 Introduction and installationSafyr5 was designed for Microsoft Windows (Windows 98 up to Win-dows 10).

3 Safyr5 retains all the functions of the previous version (Safyr4W) andadds new features for controlling the 3D-Rotator. In addition, a sim-ple data browser, based on Anisoft42, is included. Installation of thesoftware is straightforward: double click on the instructions of the installation wizard. The software will be in-stalled into the directoryC:\Agico\Safyr5and a default data directoryC:\MFKD atawill be Instrument settingsMake sure that the 3D-Rotator is connected to the MFK Pick-Up the software, go to theInstrument settingsand select Anisotropymeasurement with 3D-Rotator (see ). TheInstrument settingswin-dow is accessible viaSettingsin the main menu (shortcutF12). Measur-ing parameters such as Measurement mode, Field intensity, Operatingfrequency, and specimen volume can be set using this 2: Instrument settings windowApplication notepage 33D InitializationPress theInitializebutton on main screen to start the initialization pro-cedure.

4 Results of such routine are shown on The software auto-matically recognizes whether the 3D-Rotator is connected, it sets volt-age for appropriate speed of rotation (voltage is in the AD converterunits and its value should be in the range from 1450 up to 1650), and itmeasures the speed (duration of one revolution which should be closetothe2750ms). Then initialpositionof the3D-Rotatorisset. Aftera suc-cessful initialization, you are prompted to wait 10minutes until the in-strument is stabilized. The stabilization helps to eliminate the coil driftand it is especially necessary in case of the low-susceptibility specimenswith low degree of anisotropy. After initialization, you are promptedto wait 10minutes until the instrument is stabilized. The stabilizationhelps to eliminate the coil drift and it is especially necessary in case ofthe low-susceptibility specimens with low degree of 3: Initialization screen, 3D-Rotator informations are highlightedin red notepage 43D Rotator4 Measuring Specimen mountingIt should be noted that, due to the design of the 3D-Rotator, the spec-imen tightening screw is accessible only when the inner shell of therotator is turned off the initial position ( ).

5 The mounting positionof the shell is automatically set after the initialization routine or when-ever the measurement is finished. The specimen has to be inserted intothe shell with the specimen arrow (x-axis) pointing down and matchingwith the arrow drawn on the shell and fixed using the screw as shownon This screw has to be tightened gently to prevent damage ofthe shell. Be carefull during the loosening of the fixing screw as 4: A - position for specimen insertion , B - inserting and CalibrationCalibration routine consists of two steps: measurement of bulk suscep-tibility of the calibration standard for determination of the gain andanisotropy measurement for obtaining Delta (phase shift) perform the ( ,mainmenuExecution/Calibration,shortcutF 3). calibration standard into the 3D-Rotator (see ) the Calibration standard values with those written onthe calibration standard.

6 If they do not match, close the Calibra-tion window and input the correct calibration standard suscep-tibility values using the main menuSettings/Calibration standardvalue(s). the calibration by pressing notepage 53D RotatorFigure 5: Calibration windowFigure 6: Position of the calibration standard for calibration calibration can be saved by pressing the calibration is unsuccessful (due to various reasons), then usetheCancelbutton to retain the old calibration of thecalibration constants mustfall within the followinglimits (Table1).ConstantValue rangeGain, Frequency , Frequency , Frequency , all Frequencies-15 -5 Table 1: Calibration values rangesApplication notepage 63D Holder correctionPerforming the holder correction routine is crucial for the correct mea-surement of weak specimens with low degree of anisotropy.

7 It is rec-ommendedtoperformcalibrationaswellas holdercorrectioneverydayto achieve the best measuring results. To perform the holder correctionroutine:Figure 7: Holder correction ( ,mainmenuExecution/Holdercorrection, shortcutF4). sure that the holder is clean and the holder correction by pressing made. Average values are correction can be saved by pressing notepage 73D Specimen measurementMainscreenofSafyr5forthemeasu rementswiththe3D-Rotatorisshownon Specimen measurement consists of following the specimen into the rotator as shown on ; theNew specimenbutton to input the specimen name, ori-entation, foliations and theAnisobutton to start anisotropy theBulkbutton to start bulk susceptibility theAuto bulkis checked, the bulk susceptibility is measuredautomatically right after the anisotropy measurement is are automatically calculated whenever all necessary dataare theSavebutton to save current measurement into the some another (hotkey:Spacebar).

8 Application notepage 83D RotatorFigure 8: Data acquisition windowApplication notepage 93D Rotator5 LimitationsThe 3D-Rotator can be used only for the standard paleomagnetic cylin-drical specimens ( mm in diameter, 22 mm in height). It is not pos-sible to measure cubic specimens or soft sediments in boxes (unless theboxes mimic the shape and size of the standard paleomagnetic speci-men).The 3D-Rotator is quite massive compared to the classical rotator ormanual holder; its bulk susceptibility is approximately -30 10 6SI onFrequency 1; this value is much higher on Frequencies 2 and 3. Con-sequently, the specimens with bulk susceptibility below 100 10 6 SIand/or with low degree of anisotropy may be measured less preciselycompared to the classical rotator or the manual holder. Always checkthe confidence angles as well as the F-tests values.

9 The F value shouldbe higher then 3 to be sure that specimen is anisotropic, F12 and F23must be higher then to be sure that there is a significant differencebetween the principal limitation may be faced while measuring very strong spec-imens (bulk susceptibility over 1 10 3SI) with anisotropy higher then300% and direction of the maximum susceptibility parallel to z-axisof the specimen; (specimens similar to the calibration standard). Theanisotropy of this kind of specimens should be preferably measuredusing the classical rotator or 15-position design with manual note that the actual process of calibration is not notepage 103D Rotator6 Maintenance and repairsImportant note:Please keep your specimens as clean as possible. Anydust particles that fall from your specimens can increase friction in be-tween 3D-Rotator parts, so the voltage for correct speed of rotator willincrease.

10 Higher voltage shortens the life-time of rotator motor. If thecontamination of the rotator is too high, then the rotation may be notso smooth or it can stop to rotate at Cleaning and setting up the rotatorIf the motor driving voltage exceeds 1700 units (as mentioned in ), then it is necessary to clean your 3D-Rotator or decrease tension onthe driving 9: Removing of the top cover of the sure that your Kappabridge is switched off, unplug the plastic screws marked by red circles on removethe top cover of the (justalittlebit, half-turnisenough)markedby big red circle on , but do not unscrew them. Unscrew twoplastic screws marked by the green circles on piece which works like a spacer. It is marked by blue | on the belt and clean it with toothbrush (or similar tool) andwarm water. Little bit of detergent can be used as notuse any solvents such as alcohol, toluene and similar two plastic screws marked by the blue circles on dismantle the bottom part of rotator as seen on notepage 113D RotatorFigure 10: Position of the screws on rotatorFigure 11: A - Plastic ring and white rubber spacer, B - correct positionof the spacer with respect to the plastic ringFigure 12: Dismantled theparts witha pieceof cloth(soft toothbrush)and warmwater with little bit of not useany solvents, it maycauses some serious damage of the 3D-Rotator.