Forensic science ink dating
Forensic science ink dating - american housewife sex chatting
By the combination of the presence or absence of each tag either a specific year or a range of years could be established.The procedure most commonly used for the detection, isolation, and analysis of these date tags in ink dating is: The comparison between the known tag and the questioned ink being examined should focus on whether the florescent compounds are the same color in the known and questioned.
In order to do this the following steps are taken: Ink dating – chemical tag: The detection of a chemical date tag can disclose the exact year that the ink being examined was manufactured.
This involves the comparison of the questioned ink being examined to a known library of inks to determine the manufacturer and formula of the ink.
Then by researching the library information or contacting the manufacturer an exact date of commercial availability can be established.
Other times the results will disclose a range of a few years as possibilities the ink could have been made.
Based on the identification of formulation, which will be discussed next, it may be possible to exclude some of the possibilities and further narrow the range sometimes to only one year.
This ink dating method primarily involves microscopic examinations and can also incorporate some basic chemical solubility testing.
Some examinations can be performed on fountain pens to determine type of nib, type of ink and the first date of introduction of each of these.This is another place where a large body of knowledge of running inks is significant, to evaluate differences that are attributable to differences in batches of inks and differences that lead to the conclusion of different formulations.The best way to establish the degree of differences that can be caused by different batches of the same formulation is to run many samples of the same ink that is known to be different batches.However, since this is a very small portion of the actual type of cases seen, we will concentrate primarily on more recent developments.Other pages discuss the use of infrared to discriminate the differences between inks that visually and microscopically look identical.Color slide film has been shown to work well, especially since a print can be made directly from a slide or used in a projector for presentation.