ASTM_E_1422_-_01.pdf

Designation:E 1422 01Standard Guide forTest Methods for Forensic Writing Ink Comparison1This standard is issued under the fixed designation E 1422;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis guide is intended to be a general guide for forensic ink examinations,both for the experienceddocument examiner(E 444)and for forensic ink comparison specialists.The aim is to include thosetechniques that will provide the most information about an ink with the least damage to the document.Therefore,this guide refers to well-reported and thoroughly tested techniques currently in use bydocument examiners in general practice and dedicated forensic ink comparison facilities.By following the procedures outlined here,an examiner can accurately discriminate ink formulasand reduce the possibility of false matches of ink samples from different sources or incorrectdifferentiation of ink samples with a common origin.1.Scope1.1 This Guide is intended to assist forensic examinerscomparing writing or marking inks.Included in this analysisscheme are the necessary tools and techniques available toreach conclusions as to the common or different origin of twosamples of ink.1.2 Identifying ink formulas as to their manufacturer or timeof manufacture as well as performing ink dating examinationsare beyond the scope of this guide.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 1535 Test Method of Specifying Color by the MunsellSystem2E 131 Terminology Relating to Molecular Spectroscopy3E 284 Terminology of Appearance4E 444 Guide for Descriptions of Scope of Work Relating toForensic Document Examiners42.2NIST Standards:NBS Standard Sample No.2106 ISCC-NBS Centroid ColorCharts5NBS Special Pub.440Color:Universal Language andDictionary of Names53.Terminology3.1 Definitions:3.1.1 chromatographya method of separating substancesthat is widely used in analytical and preparative chemistry.Itinvolves the flow of a liquid or gas mobile phase over a solidor liquid stationary phase.As the mobile phase flows past thestationary phase,a solute will undergo repeated adsorption anddesorption and move along at a rate depending,among otherfactors,on its ratio of distribution between two phases.If theirdistribution ratios are sufficiently different,components of amixture will migrate at different rates and produce a charac-teristic pattern(chromatogram).3.1.2 fluorescencea process by which radiant flux ofcertain wavelengths is absorbed and reradiated nonthermally atother,usually longer,wavelengths.(E 284)3.1.3 infrared(IR)referring to radiant flux having wave-lengths longer than the wavelengths of light,usually wave-lengths from about 760 nm to about 3 mm.(E 284)3.1.4 lightelectromagnetic radiant energy that is visuallydetectable by the normal human observer,radiant energyhaving wavelengths from about 380 nm to about 780 nm.(E 284)3.1.5 luminescencethe emission of radiant energy duringa transition from an excited electronic state of an atom,molecule or ion to a lower electronic state.(E 131)3.1.6 metamersspecimens differing in spectral reflectance1This guide is under the jurisdiction of ASTM Committee E30 on ForensicSciences and is the direct responsibility of Subcommittee E30.02 on QuestionedDocuments.Current edition approved Jan.10,2001.Published April 2001.Originallypublished as E 1422 91.Last previous edition E 1422 98.2Annual Book of ASTM Standards,Vol 06.01.3Annual Book of ASTM Standards,Vol 03.06.4Annual Book of ASTM Standards,Vol 14.02.5Available from U.S.Department of Commerce,National Bureau of StandardReference Materials,R.B311,Chemistry Building,Gaithersburg,MD 20899.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.but having colors that match in light of one spectral composi-tion,when viewed by one observer,but may not match in lightof other spectral compositions,or when viewed by anotherobserver.(E 284)3.1.7 spectroscopyin the most general sense spectroscopyis the study of the absorption or emission of electromagneticenergy by a chemical species as a function of the energyincident upon that species.3.1.8 sourcean object that produces light or other radiantflux.(E 284)3.1.9 ultraviolet(UV)referring to radiant flux havingwavelengths shorter than the wavelengths of light,usuallywavelengths from about 10 nm to 380 nm.3.1.9.1 DiscussionLong-wave UV usually refers to thespectral range of UV-A,with wavelengths from about 315 nmto 380 nm.Short wave UV usually refers to the spectral rangeo