Introduction

This Quick Start Guide is intended for scientists to quickly get started measuring the Anisotropy of Magnetic Susceptibility (AMS) on discrete samples with the MFK2-FA Multi-function Kappabridge. For bulk magnetic susceptibility measurements only and details on frequency- and field-dependence of AMS measurements, the user is referred to MFK2 Multi-function Kappabridge User Guide.

Getting Started

Selecting a sample holder

In addition to the manual sample holder, there are two holders for automatic AMS measurements (Figure 1):

• 1-axis rotator, also called 2D classic holder - sample is measured in three positions
• 3D rotator - sample is measured in one single position

The 3D rotator should not be used for samples with a low susceptibility.

Figure 1: A) Position of the standard in the 1-axis Rotator. B) Position of the standard in the 3D Rotator

Activating the MFK2

1. Turn on power switch on the back of the MFK2 control unit (Figure 2)
   

Figure 2: MFK2 Control Unit

2. Ensure the sample holder is empty and clean. 

3. Select Safyr7 Software on the desktop and the program will launch.

4. Select the Activate button at the bottom left of the window main Safyr 7 window (Figure 3)

Figure 3: Activation of the MFK2

5. In the "Instrument Settings" window, select Anisotropy (AMS)/Automatic (Rotator) in the Measurement Mode box (Figure 4). Select OK.

Figure 4: Instrument Settings window

6. Wait for the initialization of the instrument. Select OK when complete (all actions are green) (Figure 5). Wait for the instrument to stabilize for 10 minutes.

Figure 5: Instrument Activation Window when activation is completed

Measuring samples

User should verify that the Measuring Mode, Field Intensity, and Operation Frequency are properly set before beginning measurements. The instrument automatically detects the type of sample holder (3D or 2D) installed on the unit.

NOTE: If the sample holders are switched the instrument should be turned off before disconnecting the holder.

Configuring the instrument

1. Select Settings>Instrument Settings (Figure 6)
   

a. Verify the measurement mode (default is automatic).

b. Select sample shape, either cube or cylinder when using the 3D rotator (this option does not exist with the 1-axis rotator). Cylinder setting is however recommended.

c. Set Field Intensity. This value defaults to 200 A/m on start up. Recommended default field intensity is 425 A/m. 

d. Verify the operating frequency. Default value F1 (976 Hz) is recommended for basic measurements.

e. When finished, select OK. When the Instrument Configuration window appears, verify configuration is correct and select OK.

Figure 6: Instrument Settings Window (when 3D rotator is used)

2.  Select Settings>Anisotropy Settings>Orientation Parameters. Check the orientation parameters: they should be set to 12/0/12/0.

3. Select Settings>Volume/Mass Susceptibility to input a sample volume and select volume or mass normalization. Default is Volume-Normalized. IODP cubes without the corners (aka J-cubes) have a volume of approximately 7 cc. Cubes cut on the rock saw are approximately 8 cc. Cylinders (minicores) are 10 cc. Select OK when done.

Calibration and Holder Correction

When starting measurements each day a user should measure the holder and calibration standard. This should also be done if the HCORR or CALIB status at the bottom of window are red.

1. Place the AGICO standard in the holder. Position of the calibration standard varies by the holder used (see Figure 1)
   
2. Select Execute>Instrument Calibration. Ensure nothing is blocking the sample holder and press START of the "Instrument Calibration" window (Figure 7).
   

Figure 7: Instrument Calibration Window

3. If calibration finishes successfully the status bar at the bottom of the window will be green (Figure 7). Select SAVE. If the calibration is not good, the status bar will be red and the user should repeat the procedure.

4. Holder values will be cleared after saving a new calibration. Select OK in the pop up window. Remove the Calibration Standard from the holder.

5. Select Execute>Holder Correction. Click START. Anisotropy will be measured automatically in 3 positions. If successful, select SAVE. If the holder values are suspicious a window will appear to warn the user. Holder correction should be repeated until it is successful. However, the ship environment/noise always creates suspicious values for the holder correction. It is at the user's discretion to accept or not the holder correction values.

Measuring a Sample

1. Select New Specimen (green button at the bottom left corner of the Safyr7 main window, Figure 8)
   

Figure 8: Main Safyr7 window with an invalid holder correction value. Note the red HCORR at the bottom of the window.

2. Enter the Cube ID (e.g., CUBE9594971) in the "New Specimen" window or use the bar code scanner gun (Figure 9).

3. Enter the orientation angles (also called Sampling Angles). This corrects for the orientation of the sample in the holder.

1. 1. If using the 3D holder (aka 3D rotator), enter an Azimuth of 0 and a dip of 90.
   2. If using the 2D holder (aka 1-axis rotator), leave the Azimuth and Dip fields blank.

4. Select OK (Figure 9).

Figure 9: New Specimen Window

5. Secure the sample in the holder.

a. When using the 3D holder, position the sample in the holder as specified in the user interface. There are two possible positions: cylinder (Figure 10A) and cube (Figure 10B). This will be the only position the discrete sample will be placed in. Cylinder position (Z axis vertical) is recommended because it reduces uncertainty on the angle of the Z axis in the sample holder.

Figure 10: Sample in 3D Holder using A) the Cylinder setting and B) the Cube setting

 b. When using the 2D holder, the cube will be placed in three positions (Figure 11).

Figure 11: Sample positions for 2D Holder

6. Measure the anisotropy.

1. 1. When using the 3D holder, select the big green ANISO button at the bottom of the Safyr7 window (Figure 12A). 
   2. When using the 2D holder, select the green ANISO button at the bottom of the Safyr7 window corresponding to the position of the sample in the holder (e.g., ANISO1 for the first position) (Figure 12B).

If the 'Auto BULK' box is selected, the measurement will be fully automated and the bulk magnetic susceptibility measurement will be taken immediately following the anisotropy measurement at the third position.

Figure 12: Safyr7 Window when using the (A) 3D holder or (B) 2D holder after new specimen information has been entered. Note the 'Aniso' button is green when the instrument is ready.

7. When the measurements are complete, select SAVE.

8. The user can then continue measuring samples by clicking the NEW SPECIMEN button at the bottom left of the Safyr7 main window.