1、Designation: E2494 08Standard Guide forExamination of Typewritten Items1This standard is issued under the fixed designation E2494; 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 i
2、ndicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers procedures that should be used byforensic document examiners (Guide E444) for examinationsand comparisons involving typewritten items and re
3、latedprocedures.1.2 These procedures are applicable whether the examina-tion and comparison is of questioned and known items or ofexclusively questioned items.1.3 These procedures include evaluation of the sufficiencyof the material (questioned, or known, or both) available forexamination.1.4 Proced
4、ures are also given for taking exemplars fromtypewriters and the proper handling of typewriters or parts oftypewriters that might be relevant.1.5 These methods can also be applicable (in whole or inpart) to examinations of documents prepared on other impactand nonimpact printing devices.1.6 The part
5、icular methods employed in a given case willdepend upon the nature of the material available for examina-tion.1.7 This guide might not cover all aspects of unusual oruncommon examinations of typewritten items.1.8 This guide cannot replace training (Guide E2388)orexperience and should be used in conj
6、unction with professionaljudgment.1.9 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.10 This standard does not purport to address all
7、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:2E444 Guide for Scope o
8、f Work of Forensic DocumentExaminersE1658 Terminology for Expressing Conclusions of ForensicDocument ExaminersE1732 Terminology Relating to Forensic ScienceE2195 Terminology Relating to the Examination of Ques-tioned DocumentsE2287 Guide for Examination of Fracture Patterns and PaperFiber Impression
9、s on Single-Strike Film Ribbons andTyped TextE2331 Guide for Examination of Altered DocumentsE2388 Guide for Minimum Training Requirements for Fo-rensic Document ExaminersF221 Terminology Relating to Carbon Paper and InkedRibbon Products and Images Made TherefromF909 Terminology Relating to Printers
10、F1457 Terminology Relating to Laser Printers3. Terminology3.1 For definitions of terms in this Guide, refer to Termi-nology E1732 and Terminology E2195. Some useful defini-tions of terms can also be found in the other Terminologystandards in 2.1.3.2 Definitions:3.2.1 ball element, nan element used i
11、n a single elementtypewriter in which the fully formed characters are located onthe outer surface of a sphere-like device. Frequently calledgolf-ball element.3.2.2 baseline, nthe ruled or imaginary line upon whichtypewriting appears to rest.3.2.3 carbon paper, na sheet composed of a supportingsubstr
12、ate on one or both sides of which is a coating containinga transferable (usually colored) material. The coating is of suchnature that it will transfer in part or entirely to a copy sheet atthe point of pressure contact. F2211This guide is under the jurisdiction of ASTM Committee E30 on ForensicScien
13、ces and is the direct responsibility of Subcommittee E30.90 on Executive.Current edition approved July 1, 2008. Published August 2008. Originallyapproved in 2007. Last previous edition approved in 2007 as E2494 07. DOI:10.1520/E2494-08.2For referenced ASTM standards, visit the ASTM website, www.astm
14、.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesNOTICE: This
15、 standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International (www.astm.org) for the latest information13.2.4 character, nany language symbol (for example,letter, numeral, punctuation mark, or other sign), other symbol,or ornament. E21953.2.5 character pi
16、tch, nthe number of characters that canbe printed in a horizontal 1 in. (25.4 mm). F14573.2.6 character spacing, nthe width allotted to each char-acter in a fixed pitch (monospacing) typewriter or to the basicunit in a proportional spacing typewriter; usually expressed inmillimeters or as a fraction
17、 of an inch. Synonym for horizontalescapement.3.2.7 correctable ribbon, na ribbon that produces animage that is designed to be completely removed from thesubstrate by means of lift-off.3.2.8 correction media, nribbons, tapes, and sheets de-signed to be struck by the typeface to cover-up or lift-off
18、typedtext.3.2.9 cover-up, nthe obliteration of one or more imagesby means of an opaque material similar in color to thesubstrate. F2213.2.10 daisy wheel element (print wheel), nan elementused in a typewriter in which the fully formed characters arecontained on the ends of finger-like projections rad
19、iating outfrom the center of a disk.3.2.11 electric typewriter, na typewriter in which anelectromechanical device causes the type element to be acti-vated when the keys are struck. F9093.2.12 electronic typewriter, nan electric typewriter inwhich the keyboard input is received by an electronic proce
20、ssorbuilt into the typewriter. This unit then controls the print headand other features to produce the typing action. F9093.2.13 element, nthe interchangeable typeface carrier of asingle element typewriter. See ball element, daisy wheelelement, thimble element.3.2.14 fabric ribbon, nan inked ribbon
21、wherein the sub-strate is a woven cloth material, such as nylon, cotton, silk, etc.F2213.2.15 fixed pitch, adjdescribes a character set in which allcharacter cells are of equal width. (See proportional spacing.)F14573.2.16 impact printer, na printer in which printing is theresult of mechanical impac
22、ts.3.2.17 individualizing characteristics, nmarks or proper-ties that serve to uniquely characterize.3.2.17.1 DiscussionBoth class characteristics (marks orproperties that associate individuals as members of a group)and individual characteristics (marks or properties that differ-entiate the individu
23、al members in a group) are individualizingcharacteristics.3.2.18 inked ribbon, na ribbon composed of a supportingsubstrate of film, fabric, or paper and a coating or impregnationof a coloring material. The coloring material is of such naturethat it will transfer in part or entirely to a copy sheet a
24、t the pointof pressure contact. F2213.2.19 lift-off, nthe removal of one or more images ofcopy from the substrate by transferring to an intermediatemember. F2213.2.20 line spacing, nthe distance between successivelines of text, usually measured from baseline to baseline, andusually expressed in mill
25、imeters or as lines per inch fortypewritten text. Synonym for vertical escapement.3.2.21 manual typewriter, na typewriter whose operationdepends solely upon the mechanical action powered by theoperator.3.2.22 monospacing, nsee fixed pitch.3.2.23 multi-strike film ribbon, na ribbon wherein thesubstra
26、te film such as polyester is coated or impregnated withan ink which allows several different imprints to be made frommultiple overstrikes on the same location on the ribbon, andstill result in full characters being printed. F2213.2.24 nonimpact printer, na printer in which imageformation is not the
27、result of mechanical impacts. F9093.2.25 original typed text, ntyped text imprinted onto thesurface of a substrate as the result of the impact of a typeface.3.2.26 printer, nan output unit that produces durablehard-copy record of data in the form of a sequence of discretegraphic characters belonging
28、 to a predetermined character set.F9093.2.27 proportional spacing, na system of printing wherethe character spacing is set in accordance with the characterwidth. See fixed pitch.3.2.28 single element typewriter, na typewriter that gen-erates text via interchangeable “elements” that each contain aful
29、l set of characters.3.2.29 single-strike film ribbon, nan inked ribbon whereinthe substrate is a plastic film material such as polyethylene,where each area of the ribbon is capable of producing only oneimage. F2213.2.30 single-strike paper ribbon, nan inked ribbonwherein the substrate is paper, wher
30、e each area of the ribbon iscapable of producing only one image. F2213.2.31 thimble element, nan element used in a typewriterin which the fully formed characters are located on the ends offinger-like devices that are similar to a daisy wheel except thatthe device is formed to produce a cup-like or t
31、himble structure.3.2.32 thread count, nthe total number of warp and fillingthreads in one square inch of fabric. F2213.2.33 typebar, na bar, mounted on a typewriter, that holdsa type slug(s).3.2.34 type element, nsee element.3.2.35 typeface, nthe portion of the element or type slugthat projects from
32、 the body and contacts the surface of thesubstrate to form the character.3.2.36 type slug, nthe block (usually metal) attached tothe end of the typebar that bears the typeface.3.2.37 typestyle, na particular variant of a type design.E2494 0823.2.38 typestyle classification scheme, na hierarchicaltax
33、onomic schematic, key, or computer database that can beused to determine the source of a particular typestyle.3.2.38.1 DiscussionThese schemes are only an aid forsearching a typestyle library and are not a substitute for actualreference materials in the typestyle library.3.2.39 typestyle library, na
34、n organized collection of ref-erence samples of typestyles and related materials.3.2.39.1 DiscussionReference materials can also includeinformation such as typestyle catalogs, treatises relative totypography and the design of typestyles used on typewritersand other printing systems, typewriters, typ
35、e slugs, typeelements, actual strike-ups, and instruction and repair manuals.Available relevant data on each typestyle should be collectedand maintained.3.2.40 typewriter, na self-contained machine forcharacter-by-character direct writing by means of keyboard-operated typefaces.3.3 Definitions of Te
36、rms Specific to This Standard:3.3.1 alignment, nthe adjustment of various mechanismsof a typewriter to ensure the even printing of the characters andtheir proper positioning relative to the baseline and to the othercharacters.3.3.2 alignment defect, na deviation from the intendedappearance or positi
37、on of a character relative to anothercharacter. see impression defect, motion defect.3.3.2.1 DiscussionAlignment defects are usually catego-rized as vertical misalignment (character too high or lowrelative to the baseline established by the other characters),horizontal misalignment (character too fa
38、r to the left or rightrelative to other characters), and twisted or leaning (characterleans to the left or to the right); because they are corrected inthe alignment process, impression defects are considered asalignment defects.3.3.3 bead defect, ninked or uninked impression or hole inthe paper caus
39、ed by a contaminant particle encased in platingmaterial located on or adjacent to the printing area of thetypeface on a metal coated element.3.3.4 family (of type), na class of type designs sharingbasic qualities of style and artistic expression that differentiateit from other similar designs.3.3.5
40、flashing, nexcess material from the molding pro-cess.3.3.6 impression defect, na deviation from the intendedevenness in appearance of a character over the entire impres-sion of the character or relative to the impression of anothercharacter. See off-foot.3.3.7 motion (as related to typebar typewrite
41、rs), nthedistance traveled by the mechanism for case shifting (usuallyby the typebar segment or the carriage) and the correspondingseparation of the characters on the type slug.3.3.8 motion defect (as related to typebar typewriters), nadeviation from the intended evenness in appearance of thebaselin
42、e alignment of unshifted characters relative to shiftedcharacters.3.3.9 off-foot, nthe lack of desired and optimum unifor-mity of contact between the typeface and the substrate.3.3.9.1 DiscussionWhile the on-feet adjustment of thetypewriter evens the impression of the upper and lowerportions of all
43、the characters, this term is also applied touneven impressions that are heavier or lighter on the sides orcorners (usually due to misalignment or distortion of individualtypebars).3.3.10 on-feet, nthe desired and optimum uniformity ofcontact between the typeface and the substrate3.3.11 on-feet adjus
44、tment, nthe positioning and setting ofvarious mechanisms of a typewriter to ensure the even printingof the upper and lower portions of the characters.3.3.12 rebound, na double impression of a typed charac-ter, the second lighter than and overlapping the first.3.3.13 typeface defect, ndeviation from
45、the intended ap-pearance of a character due to physical damage to the typefaceor its malformation in manufacture.4. Significance and Use4.1 The procedures outlined here are grounded in thegenerally accepted body of knowledge and experience in thefield of forensic document examination. By following t
46、heseprocedures, a forensic document examiner can reliably reachan opinion concerning the source of the item(s) examined.4.2 The examinations described in this guide pertain tothose documents prepared on typewriters and can consist of awide range of forensic examinations. Some or all of theseprocedur
47、es can also be applicable to examinations of docu-ments prepared on other impact and nonimpact printing de-vices.4.2.1 Examinations can be conducted to classify a typestyleand to determine the possible make and model of typewriter(s)by comparison with a typestyle library.4.2.2 Examinations and compa
48、risons of typewritten docu-ments can be conducted for the purpose of determiningwhether or not they are from a common source.4.2.3 Examinations and comparisons of typewritten docu-ments can be conducted for the purpose of determiningwhether or not they were produced using a particular type-writer or
49、 type element.4.2.4 Examinations and comparisons of a typewritten docu-ment(s) with a typewriter (or particular part(s) of a typewriter)or type element can be conducted for the purpose of determin-ing whether or not a document was prepared with thatequipment.4.2.5 Examinations and comparisons of a typewritten docu-ment(s) with typewritten documents of known date can beconducted for the purpose of determining whether or not adocument was prepared on or about the date indicated.4.2.6 Examinations of typewritten docume
