ASME B89.1.14:2018 pdf download

ASME B89.1.14:2018 pdf download.Calipers
1 SCOPE
This Standard provides the essential requirements for the specification, verification, and calibration of calipers, including vernier, dial, electronic digital, and specialty calipers. ISO 13385-1 provides for the international defi- nition of the design and metrological characteristics of calipers important in the specification, manufacture, and purchase of calipers; however, ISO 13385-1 does not provide specification values, detailed test methods, or sufficient discussion of traceability and measurement uncertaintytoensureconsistentpracticeinthecalibration ofcalipers. This Standard is intended to complement, not contradict, ISO 13385-1. Fortheverificationorcalibration of calipers, this Standard provides sufficient detail such that the user does not require access to ISO 13385-1.
2 DEFINITIONS
The definitionsin ASME B89.7.1,ISO13385-1:2011,and JCGM 200 apply in the use of this Standard.
4 CALIPER DESIGN
4.1 General AsdefinedinISO13385-1,calipersshallincorporatethe use ofa movable slider with a measuring jaw that moves along a frame or beam with a stationary jaw to provide outside, inside, and when designed, step and/or depth measurements. The general design and workmanship of calipers shall be such to ensure compliance with the requirements of this Standard and ISO 13385-1 across the measuring range ofthe caliper and in any orientation, unless otherwise specified by the manufacturer. 4.2 Least Count (a) Vernier calipers using SI units shall provide read- ings to a least count of0.05 mm or 0.02 mm. Dial calipers usingSI unitsshallprovidereadingstoaleastcountof0.05 mm,0.02 mm, or0.01 mm. Electronicdigitalcalipers using SI units shall provide readings to a leastcountof0.01 mm. (b) Vernier or dial calipers using U.S. Customary units shall provide readings to a least count of 0.001 in. Electronic digital calipers using U.S. Customary units shall provide readings to a least count of 0.001 in. or 0.0005 in.
5 MAXIMUM PERMISSIBLE ERRORS
5.1 General The maximum permissible errors (MPE) are specified limit values for errors that apply to all measurements permitted for use of the caliper as defined by the manu- facturer and following proper operation and zero setting with the outside measuringfaces. Forgeneral guidance on good operating procedures involving calipers, see Nonmandatory Appendices A and B.5.2 Operator Calipers are manually operated indicating measuring instruments and as such the measurement results are dependent on the skill of the operator. All specifications applywhen a reasonably skilled operator uses the caliper in a manner consistent with normal operation of the caliper and in accordance with the manufacturer’s recommendations. 5.3 Zero Setting Mostcalipers are equipped with the abilityto adjustthe zero point. For calipers with adjustable zero points, the metrological characteristics described in this Standard (see para. 5.10) apply when the outside measuring faces are properly brought into contact with each other for zero setting. For calipers without an adjustable zero, e.g., some vernier calipers, there may be a nonzero error when the outside measuring faces are brought together. This error shall be included in the evaluation of the metrological characteristics without correction. 5.4 Indication The specified MPE values apply to any and all unique measurement indications made under reasonable use of the caliper. Averaging ofseveral test values or other data treatment is not permitted when determining confor- mance to specifications.5.5 Temperature All specifications applyata rated operatingcondition of 20°C (68°F) unless otherwise specified. The effective nominal coefficient of thermal expansion (CTE) of a caliper in the temperature range 10°C to 30°C shall be (11.5 ± 1.0) × 10 −6 /°C. If not, then the effective nominal CTE with its uncertainty shall be supplied by the manufacturer. Caliper specifications have a rated operating condition of 20°C (68°F); therefore, the test values observed in a verification test shall be corrected to 20°C (68°F) to obtain the error of indication that the caliper would have produced had the test been performed at 20°C (68°F). If temperature correction to 20°C (68°F) is not performed, this Standard allows the consequences to be included in the evaluation ofthe measurement uncer- tainty (see Nonmandatory Appendix C).