Petrographic Image Capture and Archiving Tool (PICAT):User Guide
Author: | W. Crawford, C. Bennight |
Reviewer(s): | J. Beck |
Management Approval (Name, Title, Date): | D.J. Houpt |
Audience: | Scientists |
Origination date: | 08/24/10 |
Current version: | DRAFT (1) 09/06/10 |
Revised: | V1.1 | 1/6/2014 (IODP-II) |
Domain: | Imaging |
System: | |
Keywords: |
Introduction
This system was designed to digitally photograph Petrographic Thin Section samples, capturing the entire slide in an efficient manner in both cross-polarized and single (plane)-polarized states. Microscopes are commonly used for imaging thin sections, but they do not have a field of view wide enough to image the entire specimen. A whole specimen view is needed to provide a map (or guide) showing the relationship of the entire sample to specifically captured higher-detailed regions. The most common method of obtaining a full specimen image has been with the use of a modified flat bed or film scanner. Whereas these methods have been successful in some instances, they are cumbersome, slow, and tedious when the entire workflow process is considered.
The PICAT (Petrographic Image Capture and Archival Tool) provides an easy and versatile imaging process that captures a publication-quality image (8 x 10 inches at 300 DPI) within seconds rather than minutes. When coupled with a workflow-optimized software package, the time, effort, and training needed to capture thin section image data is significantly reduced. The live image displayed on a computer monitor instantly shows errors in exposure, focus, color balance, and cropping. The operator is confident the image is correct before rendering the sample to digital state.
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Clean the polarizing filters with the same care as cleaning a lens. Begin with the least aggressive technique, such as a camelhair brush, followed perhaps by lens cleaner and fluid. Never apply friction to the glass before brushing with a camelhair brush to remove grit or particles. Be aware of substances that may be abrasive to the filter surface.
Disassembly of the Filter Module
Note the following when working with or disassembling the filter module:
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The "take home message" here is: assembly of the magnetic couplings with too small a gap is bad. Assembly of the lower magnetic coupling above the surface of the specimen plate is bad.