ASTM_D_5720_-_95_2009.pdf

Designation:D572095(Reapproved 2009)Standard Practice forStatic Calibration of Electronic Transducer-Based PressureMeasurement Systems for Geotechnical Purposes1This standard is issued under the fixed designation D5720;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.Scope1.1 This practice covers the procedure for static calibrationof electronic transducer-based systems used to measure fluidpressures in laboratory or in field applications associated withgeotechnical testing.1.2 This practice is used to determine the accuracy ofelectronic transducer-based pressure measurement systemsover the full pressure range of the system or over a specifiedoperating pressure range within the full pressure range.1.3 This practice may also be used to determine a relation-ship between pressure transducer system output and appliedpressure for use in converting from one value to the other(calibration curve).This relationship for electronic pressuretransducer systems is usually linear and may be reduced to theform of a calibration factor or a linear calibration equation.1.4 The values stated in SI units are to be regarded as thestandard.The inch-pound units in parentheses are for informa-tion only.1.5 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.Specific precau-tionary statements are given in Section 7.2.Referenced Documents2.1 ANSI/ISA Standards:2S37.1(R1982)Electrical Transducer Nomenclature and Ter-minologyS37.3(R1982)Specifications and Tests For Strain GaugePressure TransducersS37.6(R1982)Specifications and Tests For PotentiometricPressure TransducersS37.10(R1982)Specifications and Tests For PiezoelectricPressure and Sound-pressure Transducers3.Terminology3.1 Terms marked with“(ANSI,ISA-S37.1)”are takendirectly from ANSI/ISA-S37.1(R1982)and are included forthe convenience of the user.3.2 Definitions of Terms Specific to This Standard:3.2.1 absolute pressurepressure measured relative to zeropressure(vacuum)(ANSI,ISA-S37.1).3.2.2 accuracyratio of the error to the full-scale output orthe ratio of the error to the output,as specified,expressed inpercent(ANSI,ISA-S37.1).3.2.3 ambientconditionsconditions(pressure,temperature,etc.)of the medium surrounding the case of thetransducer(ANSI,ISA-S37.1).3.2.4 best straight lineline midway between the twoparallel straight lines closest together and enclosing all outputversus measurand values on a calibration curve(ANSI,ISA-S37.1).3.2.5 bondedpermanently attached over the length andwidth of the active element(ANSI,ISA-S37.1).3.2.6 bourdon tubepressure-sensing element consisting ofa twisted or curved tube of non-circular cross section that tendsto be straightened by the application of internal pressure(ANSI,ISA-S37.1).3.2.7 calibrationtest during which known values of mea-surand are applied to the transducer and corresponding outputreadings are recorded under specified conditions(ANSI,ISA-S37.1).3.2.8 calibration curvegraphical representation of thecalibration record(ANSI,ISA-S37.1).3.2.9 calibration cycleapplication of known values ofmeasurand,and recording of corresponding output readings,over the full(or specified portion of the)range of a transducerin an ascending and descending direction(ANSI,ISA-S37.1).3.2.10 calibration recordrecord(for example,table orgraph)of the measured relationship of the transducer output tothe applied measurand over the transducer range(ANSI,ISA-S37.1).1This practice is under the jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.95 on InformationRetrieval and Data Automation.Current edition approved Feb.15,2009.Published March 2009.Originallyapproved in 1995.Last previous edition approved in 2002 as D5720 95(2002).DOI:10.1520/D5720-95R09.2Available from Instrument Society of America,P.O.Box 12277,ResearchTriangle Park,NC 27709,http:/www.isa.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.11 calibration traceabilityrelation of a transducercalibration,through a specified step-by-step process,to aninstrument or group of instruments calibrated by the NationalInstitute of Standards and Technology(ANSI,ISA-S37.1).3.2.12 capsulepressure-sensing element consisting of twometallic diaphragms joined around their peripheries(ANSI,ISA-S37.1).3.2.13 diaphragmsensing element consisting of a thin,usually circular,plate that is deformed by pressure differentialapplied across the plate(ANSI,ISA-S37.1).3.2.14 differential pressuredifference in pressure betweentwo points of measurement(