1、AN AM E R IC AN NAT IO NAL STANDARDASME B89.4.23-2020X-Ray Computed Tomography(CT)Performance EvaluationASME B89.4.23-2020X-Ray ComputedTomography(CT)PerformanceEvaluationAN AMERICAN NATIONAL STANDARDTwo Park Avenue New York,NY 10016 USAxDate of Issuance:November 30,2020The next edition of this Stan
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11、pyright 2020 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword.ivCommittee Roster.vCorrespondence With the B89 Committee.vi1Scope.12Introduction.13References.34Definitions.35Examples of Rated Operating Conditions.46Metrological Specifications.67Testin
12、g.88Compliance With Specifications.12Mandatory AppendicesITest Object Materials.15IIMathematicalAdjustmentstoTestObjectsWithaBaseMaterialThatIsLow-DensityandLow-CTE17IIIMetrological Traceability of ASME B89.4.23 Test Values.19IVTest Value Uncertainty.20Nonmandatory AppendicesADefault Test Objects.21
13、BBidirectional Length.27CSupplementary Test Procedure When Using Test Objects With Low-Density and Low-CTE BaseMaterials.28Figures7.4.1-1Mandatory Work-Zone Measurement Planes and Lines.107.4.3-1Example Test Protocol for One Rated Material.14A-1-1A Square Two-Piece SphereHole Plate With Covering Hol
14、e Plate.22A-2-1Sphere Plate With and Without an Obstructing Body.24A-2-2Scalable Design.24A-2-3Further Orientations of the Test Object.25A-3-1Aluminum 3D Test Structure With Infused Silica Spheres.26B-1-1Bidirectional,Unidirectional,and Center-to-Center Lengths.27TableI-1-1CTEs of Material Classes.1
15、6Form7.4.3-1Test ProtocolTemplate forUp toThreeRated Materials and aTest Object With One MeasurementPlane.13iiiFOREWORDThe application of X-ray computed tomography(CT)for dimensional metrology has become common in many indus-tries.ThisisprimarilyduetotheabilityofCTsystemstomeasureinsideaworkpiecewit
16、houtrequiringtactileoropticalaccess.However,there are currently no standards that address the performance evaluation of CT systems in a way thatincludes material influence,which is a dominant source of error when these systems are used to evaluate typical work-pieces.For this reason,The American Society of Mechanical Engineers(ASME)decided to form the B89.4.23 WorkingGrouptoproduceastandardforCTperformanceevaluation.ThisStandardistheresultofsignificanteffortbytheworkinggroup to develop a perform
