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To calibrate the detector select Instruments> CameraXMSL: FPD Calibration from the main IMS menu (Figure 3).  The flat panel detector (FPD) calibration utility window will open (Figure 5). The purpose of this utility is to collect images that will be used to perform offset and gain corrections for all images acquired with the FPD.  The calibration process requires two images: Dark (Offset) and White (Gain).

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To capture the DARK image:

1.  Select the tab labeled DARK-1 (Figure 5).
   1. The default exposure values are automatically displayed and are the recommend values, but you may set other values. Be aware that the dark saturation (image intensity saturation) must be 7% or lower and you need to capture at least 100 images for stacking. 
   2. Default values are Image stack: 100, kV: 80, mA: 0.7, Integration Time: 1 ms
2. Click the Take DARK Image button.
   1. The X-Ray Image Acquisition window will open (Figure 7).  During acquisition, the image window appears black but you will see values in the histogram and in the image line profile.

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3. Check the saturation value and confirm that is less than 7% (Figure 3). If not, adjust the exposure values and repeat.

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White Image Calibration

The WHITE image is used for the gain correction after the offset correction with the dark image is completed. 

To capture the WHITE image:

1. Select the tab labeled WHITE-2 (Figure 8). 
   1. The default exposure values are automatically displayed and are the recommend values, but you may set other values. Just be aware that the maximum intensity cannot exceed 99%. 
   2. Default values are Image stack: 20,  kV: 112, mA: 1.0, Integration Time: 120 ms
2. Click the Take WHITE Image button.
   1. The X-Ray Image Acquisition window will open (Figure 9).
   2. During acquisition, the image window appears white shading to darker grey on the left and right edges.

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To confirm that the offset and gain calibration have been done correctly, follow this procedure.  Note that this is an optional step, but is a good practice to ensure quality x-radiographs will be produced when imaging core.

1. Select tab TEST-3 2 (Figure 10)

2. Place a core over the detector and take an image.

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3. Once the exposure is completed, you’ll be returned to the FPD Calibration Utility window (Figure 10).

4. Select tab CORRECTED-4 (Figure 11). 

a. The image shown is the raw image with the gain and offset correction applied. 

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c. The shading seen in the WHITE image should be nearly gone.

5. Select the DIFF-5 tab to view the DIFFERENCE image (Figure 11)

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c. If the core itself is covered by the mask, then there is an issue with the calibration

6. Select the PROCESSED-6 tab to review the automatically processed image (Figure 12).

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When you have completed acquiring both images and validating the calibration, click Save Calibration Images. These images will be automatically applied to the images. Or select Cancel and revert to the previous calibration images.   The filenames of the DARK and WHITE image files are stored in the I_PI_GOSCAN.ini configuration file.  When the IMS program is initiated, these images are opened and the data is extracted.  If these files are missing you will be notified and will have to complete the calibration process before any images can be acquired.

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C. Set Measurement Parameters

a) Instrument Setup

Configuration values should be set during initial setup and configuration by the technician or scientist(s).  There should be no need to change these values unless the configuration file is corrupted or the hardware setup is changed.

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1. Ensure the values in the window are set as shown in Figure 14.
   1. The instrument X-offset is measured from the home switch to the center pixel of the detector (Figure 15).
   2. This value must be updated should the detector position change or if the home switch on the track is modified.
2. Click ACCEPT to save the changes and write them to the configuration file.  Click Cancel to revert to previous values.

Figure 14. XMSL Parameters Window.

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Figure 15. XMSL Measurement Editor Window.

D. Preparing Sections

1. Wipe off excess moisture and/or mud from the core liner.
2. Tape any drill holes, when applicable.

Note: All core sections entering the NGR must be completely dry. Any moisture or liquid present will DAMAGE the instrument.

E. Making a Measurement

Prior to imaging cores, especially at the start of an expedition, the user must:

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F. Evaluating your Measurement

G. IMS Utilities

General Image Utility

The image utility can be found under Instruments > Camera: Image Utility (Figure 1122).  This utility is useful for determining the proper voltage, current, and integration (exposure) time for imaging cores.  User can also review the processed images in this utility.

1. Adjust the integration time, number of images to stack, kV, and mA on the right side of the window (Figure 3022).
   1. REMEMBER: Lower voltage with a longer exposure time may increase image contrast.  High voltage does not equal better images.
2. Select Take TEST Image
3. Wait for the x-ray source to ramp up and collect x-radiographs
4. Review the test images
5.  Repeat process until image is acceptable
6. Note the settings.  For these settings to be used, the user needs enter them under DAQ > Measurement Editor
7. Select Close to return to the main IMS window.

Image Modified

Figure 30- 22. General Image Utility User Interface Window.  This utility is used test exposure settings before imaging a section.  The histogram (upper left) will be displayed when the ROI box tool is used and the line profile (lower left) is displayed when the ROI line tool is used.

Automatic Image Processing: Image Processing Utility

The raw .tif IMS images are automatically saved during image collection.   IODP provides two methods for processing the raw images.:

1. Automatic Image Processing: A program written in LabVIEW.  Processing is automatically completed by the software after images are collected.  User is able to make adjustments using the Image Process Utility under the Instruments menu.  The processed image is given a scale bar with the correct offset and the core identification information is overlaid at the top of each image.
2. Manual Image Processing: A program written in “GO”.  User must initiate and control the image processing settings.  Scale bar provided is 1 cm black and white lines along the left side of the image.  A stitching guide is also provided on the processed image.

Image Processing Utility

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This utility has the following purpose:

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