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Laboratory Equipment |
| It is necessary to equip a forensic laboratory equipped with modern scientific instruments to ensure problems can be thoroughly investigated and that test results will be reliable. Forensic Document Examination Services possesses equipment needed to deal with even the most complex document problems. Included in its inventory are the following: |
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Video-Spectral Comparator (VSC-1) |
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The VSC-1 and VSC-2CX are instruments designed to
detect the
different optical properties of document materials. Unlike the VSC-1, the VSC-2CX is a portable instrument that can be taken
outside the laboratory to examine documents in law offices, court rooms or other off-site locations. VSC testing is non-destructive and does not alter the appearance or condition of a document. These instruments are particularly effective at detecting alterations to documents, restoring erased entries, revealing original writing that has been obliterated, obscured or overwritten and differentiating inks that cannot be distinguished by the naked eye. Inks from different writing instruments often react differently when illuminated with ultraviolet and infrared light. These differences can easily be detected with the VSC-1 and VSC-2CX. |
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Quality Optical Microscopes |
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The most important instrument in the document examiner's
arsenal is the
optical microscope. Usually, critical evidence attesting to the genuine or spurious
nature of a questioned document cannot be seen by the naked eye.
The stereo-microscope provides a 3-dimensional view of an area of
interest.
Some stereo-microscopes are manufactured to lower standards. FDES only uses high quality instruments to examine document evidence. Despite their ability to inspect 3-dimensional objects, stereo-microscopes cannot generate highly magnified images often needed to determine which of two intersecting entries was made first. A binocular microscope equipped with coaxial illumination is better suited for this purpose. |
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Electro-Static Detection Apparatus (ESDA) |
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The Electro-Static Detection Apparatus (ESDA) provides the document
examiner with a non-destructive technique for detecting impressions in
paper that are invisible to the naked eye. The ESDA can also reveal
the
relative sequence of entries in ledgers, journals or medical records. FDES specialists use this instrument to restore handwritten impressions on anonymous letters and detect documents that have been fraudulently altered or back-dated. Restored impressions are preserved using adhesive-coated acetate sheets. |
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Miscellaneous Equipment |
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Light Sources |
The application of chemical eradicators, the removal of information with erasers or the application of foreign adhesives can affect the fluorescence of document materials. FDES experts use short and long wave ultraviolet light sources to detect the presence of erasures and to locate foreign adhesives used when repairing documents or resealing envelopes. Written entries erased by chemicals or erasers and the application of adhesives can often be restored by examining suspect documents under ultraviolet light. | |
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Fiber optic light guides Ultraviolet (fluorescent) lighting Ring light illuminators Infrared (tungsten) |
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Calibrated Measuring Devices |
Altered multi-page documents can contain
substituted
pages which replace those that have been removed. Typewriting added to a
document is usually misaligned with other typewritten information on
the page. FDES employ calibrated micrometers and rulers to measure
paper
dimensions accurately. Typewriter measuring grids are used to detect misaligned typed
characters. Some equipment, such as the ESDA, must be operated in a controlled environment to achieve optimum results. Ambient conditions are closely monitored and maintained within acceptable limits to ensure accurate results. |
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. Graticule eyepieces Typewriter grids Micrometers Hydrometer Rulers |
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Digital Imaging System |
Digital imaging
technology provides a fast and cost-effective alternative to
capturing and storing document images by using conventional
photographic techniques.
FDES employs digital cameras and flat-bed scanners to record and preserve the contents of documents. Once images are captured, digital filters can be used to restore obscured information on a disputed document. Images viewed through a microscope are recorded with analog or digital cameras. Dye-sublimation, inkjet and laser printers are used to generate photo-quality color prints. |
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Flatbed scanners Digital cameras Frame grabbers Adobe Photoshop Software Image Pro Plus Software |
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