ASTM_E_1856_-_13.pdf

Designation:E185613Standard Guide forEvaluating Computerized Data Acquisition Systems Used toAcquire Data from Universal Testing Machines1This standard is issued under the fixed designation E1856;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()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This guide is intended to assist the user in the evaluationand documentation of computerized data acquisition systemsused to acquire data from quasi-static tests,performed onuniversal testing machines.The report produced will aid in thecorrect use and calibration of the computerized universaltesting machine.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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:2E4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE8/E8M Test Methods for Tension Testing of Metallic Ma-terialsE74 Practice of Calibration of Force-Measuring Instrumentsfor Verifying the Force Indication of Testing MachinesE83 Practice for Verification and Classification of Exten-someter SystemsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1012 Practice for Verification of Testing Frame and Speci-men Alignment Under Tensile and Compressive AxialForce Application3.Terminology3.1 The definitions of mechanical testing terms that appearin Terminology E6 apply to this guide.3.2 Definitions:3.2.1 resolution,nfor a particular measurement device,the smallest change in the quantity being measured that causesa perceptible change in the corresponding indication.3.2.1.1 DiscussionResolution may depend on the value(magnitude)of the quantity being measured.3.2.1.2 DiscussionFor paper charts or analog indicators,the resolution should not be assumed to be better(smaller)than110of the spacing between graduations.For digital devices,thebest resolution potentially achievable is the smallest differencebetween two different readings given by the display.3.2.1.3 DiscussionFor both analog and digital devices,theactual resolution can be significantly poorer than describedabove,due to factors such as noise,friction,etc.3.3 Definitions of Terms Specific to This Standard:3.3.1 basic data,nthe digital equivalents of analogcounterparts,such as force and displacement measurements,which under static conditions are traceable to national stan-dards(see Fig.1).3.3.2 computerized data acquisition systema device thatcollects basic data from a universal testing machine during atest and calculates and presents derived data based on the basicdata collected.3.3.3 derived data,nadditional numbers derived from thebasic data through computation using software algorithms,such as a peak force or a modulus value.3.3.4 data acquisition rate,nthe rate at which digitalsamples of each wave-form(that is,force,strain,displacement,and so forth)are acquired,expressed in samples/second.3.3.5 transducer-channel bandwidththe frequency atwhich the amplitude response of a transducer channel hasfallen by 3 dB;that is,the measured signal is in error by about30%and the phase shift is 45 or greater.3.3.5.1 DiscussionThe precise amplitude and phase re-sponses vary with the electrical design of the computerizeddata acquisition system,but the 3 dB bandwidth(expressed inhertz)is a simple single measure of responsiveness(see Fig.2).1This guide is under the jurisdiction of ASTM Committee E28 on MechanicalTesting and is the direct responsibility of Subcommittee E28.15 on AutomatedTesting.Current edition approved Nov.15,2013.Published January 2014.Originallyapproved in 1997.Last previous edition approved in 2008 as E185697(2008).DOI:10.1520/E1856-13.2For referenced ASTM standards,visit the ASTM website,www.astm.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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Summary of Guide4.1 Comparative tests are performed to determine if thederived data acquired with a computerized universal testingmachine agree with results acquired on the same machine fromgraphical records or with results acquired on other testingmachines to ensure that the materials being tested are correctlycharacterized.5.Significance and Use5.1 This guide is recommended to be use