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Multi-Sensor Core Logger (MSCL) Cheat Sheet
(Updated 14 September 2009)
These six steps should be followed when logging cores. Steps 3 through 5 are required for each
coring site.
Data Management
The GEOTEK software places all data into a directory called GEOTEK DATA. At the beginning of
a cruise or project a subdirectory should be made for the data. On a cruise we would typically use
the cruise ID for this directory, e.g. TT0909. When data for a core is run a subdirectory would be
made here (i.e. data for a core would be found in: ../GEOTEK DATA/TT0909/21JC. It is also
convenient to make an additional subdirectory called CALIBRATIONS within your cruse directory.
This core directory should contain the GEOTEK raw data files, an excel spread sheet containing the
calibration run made before the core is run as well as processed data files. While the GEOTEK
system has a RAID disk system to protect data, it is highly recommended that data backups be made
on a regular basis.
Step 1: Starting the System
1. Turn on the GEOTEK multi-sensor core logger box ("Mains" switch).
2. Turn on the “Track” box that controls the track motors (middle box in main frame).
3. Turn on NCR controller box.
4. Turn on Magnetic Susceptibility meter.
5. Set Magnetic Susceptibility meter to SI Units. (Note: 0.1=10sec count, 1.0=1sec count)
6. Boot-up computer. (Turn computer on with back panel switch, then use toggle switch on
front panel, which is behind the screen door.
7. Remove clear plastic shield from between the source and detector.
8. Unlock shutter on the gamma source.
9. Open shutter with a 180o rotation. Be sure shutter locks in on top of the small knob.
NOTE: Only have the shutter open when actively using the system or you can burn out
the detector. Keep hands away from face of source.
10. Replace plastic shield.
Step 2: Testing System
1. Start the GEOTEK utilities program (util7_9.exe, short cut icon is in upper left hand corner
of computer screen).
2. Under "window", select Test Panel.
3. Press "Temperature" on Test Panel. The utility window should display temperature of probe
in centigrade. Press “temperature” again to turn off.
4. Press "Track Motor". Press “test” and motor should respond.
5. Press "Gamma Attenuation". Counts should be on the order of 19000 counts per sec (cps). If
counts are on the order of 6000 cps then the small hole shutter is being used and the shutter
should be moved the complete 180o.
6. Place water core onto track between p-wave sensors. Press “P-wave Travel Time”. Click
check box labeled “Auto Adjust PWave” and red vertical line should go to the first positive
slope cross-over.
7. Press "Zero Resistivity" (make sure nothing is on the sensor). Wait until you see "STOP"
followed by "Ready".
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8. Close util7_9.exe
Step 3: Running Standards for Resistivity (This standard should be run daily).
1. Start util7_9.exe
2. Under "window" select test panel.
3. Select zero if meter has not been zeroed as above.
4. Select resistivity on the test panel.
5. Record average of 10 measurements with no core.
6. Insert first of the six NCR standards starting with No. 1 (0ppt). Be sure that the core liner is
all that is above the sensor. Don't have the black electrical tape or end cap above the sensor.
You will need to separate the p-wave velocity sensors to allow the core to sit above the
resistivity sensor.
7. Record average of 10 measurements.
8. Insert the next NCR standard.
9. Repeat until all 6 standards have been measured.
10. The measurements on the 6 standards are entered into the Excel calibration spread sheet to
get the calibration factors needed for processing the instrument units into resistivity units.
11. Close util7_9.exe
Step 4: Running the Gamma Density Standard.
1. Start the MSCL7_9.exe program (short cut icon is on upper left corner of computer screen)
2. Click on Log New Core
3. Enter the core number and type (e.g. 09JC). If this directory exists, the program will notify
you that it is possible that some data files will be overwritten. If this is not acceptable,
answer no to the question and give another name.
4. On Setup Screen
a. Be sure “log initial calibration piece” is not checked.
b. Disable all sensors except "Gamma Attenuation".
c. Set sampling interval to 0.3cm
d. Set counting time to 5 seconds.
e. Click OK.
5. Setting up track and placing gamma density standard.
a. Place the any NCR reference between the p-wave transducers,
b. Using the controls on the track, switch the track drive to manual and move the pusher
to a position just to the right of the laser beams. Switch the motor controller back to
Auto. Press OK. Pusher will find zero.
c. On the computer screen use the track icon to move the track to 75cm.
d. Place the gamma density standard on track.
e. Click “begin logging” and then OK.
f. Calibration pieces will move through track.
g. Press OK for section 2. After inserting “pusher PVC” onto track press drag pusher
position to 105cm and then press “continue”.
h. Disable all sensors and press OK.
i. When pusher moves back for “section 3” press OK and then “end logging”.
If you will be processing the data, complete steps 6 to 12 otherwise skip to step 13.
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6. In data display window scale plot to easily pick the 10 plateaus needed for calibration. You
can scale plot by dragging a box around the data and then clicking inside the box. There are
10 plateaus in the figure. The first plateau is the all alumina section and has the lowest
gamma counts. Eight plateaus follow this minimum. The 10th plateau is at the bottom of the
figure where only water is in the standard.
7. Open the Excel spread sheet with calibration templates.
8. Use the curser to find a reasonable mean of each plateau.
9. Get gamma counts from window (lower right corner of the MSCL7_9 window).
10. Enter this number into the appropriate place in the excel spread sheet.
11. After inputting the calibration data for both resistivity and gamma density, Save AS
cal_##CT, where ##is the core number and CT is the core type; put this file in the directory
for the core you are working on.
12. In the finder window:
a. click on the core directory you are working on.
b. change the name of the data file named with the core number followed by ".dat" to
"gamma_cal_##CT.dat" where ## is the core number and CT is the coretype (e.g. JC,
TC, GC, MC etc.).
c. make a copy of the calibration data set and place it into the MV0811/calibrations
directory.
13. You can now “end logging”
Step 5: Running a Core.
You get more consistent data if the entire core is placed into the core van at one time. This
allows all core sections to equilibrate to temperature at the same rate.
1. Place the temperature probe into the bottom of the last section of the core. Use a screwdriver
to punch a template hole into the end-cap about 1/3 from the edge of the liner. Don't use the
temperature probe to punch this hole and do not remove the temperature probe by
pulling on the wires, use the cork.
2. Start the MSCL7_9.exe program if necessary.
3. Click "Log New Core"
4. Program should start in the GEOTEK DATA folder. Move to your “cruise” data folder.
5. Enter the core number, e.g. 3JC.
6. Click OK. This will create a new folder under: GEOTEK DATA/cruise data/3JC
7. On the Setup Screen:
a. Click "Log Initial Calibration Piece"
b. Enable all sensors.
c. Set sampling interval (6cm).
d. Gamma counting time 2sec.
e. Magnetic susceptibility:
i. 10 sec.
ii. SI units
iii. zero 10cm before core.
f. Nominal section length: 150cm
g. NCR zero 10cm before core.
h. click ok
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8. Place the DDW reference between the p-wave transducers, THIS MUST BE DONE TO
PROPERLY SET CORE DIAMETER MEASUREMENT. Having the DDW reference
between p-wave transducers zeros the core thickness sensor.
9. Click OK
10. Using the controls on the track, switch the track drive to manual and move the pusher to a
position just to the right of the laser beams. Switch the motor controller back to Auto. Press
OK. Pusher will find zero. (NOTE: From this point on, do NOT use the manual control to
move the pusher or you will lose the ZERO point and have to start over.)
11. On the computer screen use the track icon to move the track to 70cm.
12. Place the 0.35ppt and then the 17.5ppt NCR calibration tubes on the track to the right of the
laser beam.
13. Using track icon on the computer screen move the pusher close to the standard sections.
14. Click begin logging.
15. Click OK
16. Calibration pieces will move through track.
17. As soon as the DDW calibration piece is through the p-wave transducers remove it from
the track. The resistivity sensor needs to zero with nothing over the sensor.
18. After the pusher checks the reference position and moves to the far right of the track,
computer will ask for section 1 of the core. Click OK
19. Place first section of core on track to right of laser beams (do not cross laser beams). Do not
force core against pusher. If necessary use track icon to move track pusher back to allow
placement of core section or move the pusher closer to the core if section is shorter than
150cm. Click “Continue”
20. At Setup window:
a. Set desired sampling interval (e.g. 1 cm).
b. Set gamma count time (typically 5 sec).
c. Set magnetic susceptibility to desired time. Note if you change the averaging time in
the setup window, also change the switches on the Bartington control panel. NOTE:
bug in current program only allows you to change Mag sus time in initial set up
screen.
d. Click OK
21. Record the length of the core section measured by the MSCL into the log book.
22. Repeat steps 18 to 21 as needed.
23. With last section be careful with the temperature probe. Leave probe in section until the end
of the core has just passed the p-wave sensors, otherwise the probe will cause a spike in the
susceptibility data. Do not remove the temperature probe by pulling on the wires, use
the cork.
24. After last section, use the pusher piece (half round section) to push this section through to the
end of the core. Change the setup by disabling all sensors first.
25. End by clicking "End Logging".
Step 6:
1.
2.
3.
4.
5.
6.
Shutting down at end of session:
Remove clear plastic shield from between the source and detector.
Close shutter with 180° rotation
Lock shutter on gamma source
Replace plastic shield
Computer and sensors may remain turned on for duration of cruise.
Exit MSCL program
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