ASME B89.4.10360.2-2008 pdf download

ASME B89.4.10360.2-2008 pdf download.Acceptance Test and Reverification Test for Coordinate Measuring Machines (CMMs) — Part 2: CMMs Used for Measuring Linear Dimensions.
2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the cited editions apply. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 10360-1:2000, Geometrical Product Specifications (GPS) — Acceptance and reverification test for coordinate measuring machines (CMM) — Part 1: Vocabulary ISO 14253-1:1998, Geometrical Product Specifications (GPS) — Inspection by measurement of workpieces and measuring equipment — Part 1: Decision rules for proving conformance or non- conformance with specifications ISO 14660-1:1999, Geometrical Product Specifications (GPS) — Geometrical features — Part 1: General terms and definitions ISO/TS 23165:2006, Geometrical product specifications (GPS) — Guidelines for the evaluation of coordinate measuring machine (CMM) test uncertainty International Vocabulary of Basic and General Terms in Metrology (VIM). BIPM, IFCC, IEC, ISO, IUPAC, IUPAP, OIML, 2nd edition, 1993
Reverification tests are executed according to the user’s specifications and the manufacturer’s procedures. Issues associated with dual ram CMMs are discussed in 6.6. NOTE This International Standard does not explicitly apply to CMMs using optical probing, however if by mutual agreement the parties apply this approach to optical CMMs then additional issues, such as the following, need to be considered: ⎯ In the case of two dimensional sensors (no ram movement) an index 2D may be used for indication, e.g. E 0-2D; ⎯ In case of two dimensional systems the number and location of the measurement positions may be reduced; ⎯ Specifications for the magnification and illumination; ⎯ Artefact issues such as material and surface finish affect the test results; ⎯ Bi-directional probing may or may not be possible depending on the artefact and probing system (see Annex B).
6.2 Principle The principle of the assessment method is to use a calibrated test length, traceable to the meter, to establish whether the CMM is capable of measuring within the stated maximum permissible error of length measurement for a CMM with a specified ram axis stylus tip offset (both 0 and 150), E 0, MPE and E 150, MPE , and within the stated maximum permissible limit for the repeatability range, R 0, MPL . The assessment shall be performed by comparison of the indicated values of five different calibrated test lengths, each measured three times, relative to their calibrated values. The indicated values are calculated by point-to-point length measurements projected onto the alignment direction (see also Annex C). Each of the three repeated measurements is to be arranged in the following manner: if one end of the calibrated test length is labeled “A” and the other end “B” then the measurement sequence is either A 1 B 1 , A 2 B 2 , A 3 B 3 or A 1 B 1 , B 2 A 2 , A 3 B 3 . Other sequences such as A 1 A 2 A 3 , B 1 B 2 B 3 are not permitted. Each of the three repeated measurements shall have its own unique measured points. That is, in general, B 1 , B 2 and B 3 must be different actual points of the same target point B. Once the measurement sequence for a test length has begun no additional probing points shall be measured other than those required to measure its length; e.g., no alignment points are permitted between the measurement of A 1 and B 3 . For CMMs without workpiece thermal expansion compensation, the uncorrected differential thermal expansion between the CMM and the calibrated test length can produce a significant error, hence this International Standard also requires the disclosure of the test length CTE. For CMMs with workpiece thermal expansion compensation this thermally induced error is greatly reduced. For these CMMs a significant portion of the residual thermal error is due to the uncertainty in the test length’s CTE (i.e. resulting in imperfect thermal expansion correc