1、Designation: E 617 97 (Reapproved 2008)Standard Specification forLaboratory Weights and Precision Mass Standards1This standard is issued under the fixed designation E 617; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 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 specification covers weights and mass standardsused in laboratories, specifically classes 0, 1, 2, 3, 4, 5, 6 an
3、d7. This specification replaces National Bureau of StandardsCircular 547, Section 1, which is out of print.1.2 This specification further recognizes that InternationalRecommendation R111 exists, that describes classes E1, E2,F1, F2, M1, M2 and M3. Users may choose to reference eitherR111 or this spe
4、cification, depending on requirements.1.3 This specification contains the principal physical char-acteristics and metrological requirements for weights that areused.1.3.1 For the verification of weighing instruments;1.3.2 For the verification of weights of a lower class ofaccuracy; and1.3.3 With wei
5、ghing instruments.1.4 Tolerances and design restrictions for each class aredescribed in order that both individual weights or sets ofweights can be chosen for appropriate applications.1.5 The values stated in SI units are to be regarded as thestandard.2. Referenced Documents2.1 ANSI Standard:B 46.1-
6、1995 Surface Texture (Surface Roughness, Wavi-ness, and Lay) an American National Standard22.2 ISO Standards:International Vocabulary of Basic and General Terms inMetrology 1993, VIM, Geneve, Switzerland2Guide to the Expression of Uncertainty in Measurement2ISO/DIS 4287-1, Edition 01-Jun-95, Geometr
7、ic ProductSpecification (GPS), Determination of Surface Texture byProfiling Methods, Part 1: Terms, Definitions and Param-eters22.3 NCSL Standards:NCSL Glossary of MetrologyRelated Terms3NCSL Recommended Practice-12 Determining and Report-ing Measurement Uncertainties3ANSI/NCSL-Z540-1-1994 American
8、National Standard forCalibration-Calibration Laboratories and Measuring andTest Equipment General Requirements32.4 NIST Standards:NIST NVLAP Draft Handbook 150-2 National VoluntaryLaboratory Accreditation Program Calibration Laborato-ries Technical Guide4NIST NVLAP Handbook 150 National Voluntary La
9、bora-tory Accreditation Program (NVLAP), NIST Handbook150, Procedures and General Requirements4NIST Technical Note 1297 (1994) Guidelines for Evaluat-ing and Expressing the Uncertainty of NIST MeasurementResults42.5 OIML Standard:OIML Recommendation 33 Conventional Value of the Re-sult of Weighing i
10、n Air53. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 accuracy class of weightsa class of weights thatmeets certain metrological requirements intended to keep theerrors within specified limits.63.1.2 calibrationthe acts of determining the mass differ-ence between a standard of
11、 known mass value and an “un-known” test weight or set of weights, establishing the massvalue and conventional mass value of the “unknown”, and ofdetermining a quantitative estimate of the uncertainty to beassigned to the stated mass or conventional mass value of the“unknown”, or both. Set of operat
12、ions that establish, under1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatus and is the direct responsibility of Subcommittee E41.06 onWeighing Devices.Current edition approved Dec. 1, 2008. Published February 2009. Originallyapproved in 1978. Last previous ed
13、ition approved in 2003 as E 617 97 (2003).2Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.3Available from NCSL, National Conference of Standards Laboratories, 180030th Street, Suite 305B, Boulder, Colorado 80301.4Availabl
14、e from NIST/NVLAP, National Voluntary Laboratory AccreditationProgram, NIST, Gaithersburg, Maryland 20899. HB 150 available on-line: http:/ts.nist.gov/nvlap and Technical Note 1297 available on-line: http:/physics.nist.gov/Pubs/guidelines/outline.html.5Available from Organisation Internationale de M
15、etrologie Legale, 11 RueTurgot, 75009 Paris, France.6Definition from OIML R111.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.specified conditions, the relationship between values of quan-tities indicated by a measuring instrument o
16、r measuring sys-tem, or values represented by a material measure or a referencematerial, and the corresponding values realized by standards.73.1.3 certificate of tolerance testdocument that certifiesthat the subject weights are within specified tolerances.3.1.3.1 DiscussionIf traceability is claimed
17、, some level ofuncertainty must be addressed.3.1.4 certificate or report of calibrationdocument thatpresents calibration results and other information relevant to acalibration.83.1.5 conventional massconventional value of the resultof weighing in air, in accordance to International Recommen-dation O
18、IML R 33. For a weight taken at 20C, the conven-tional mass is the mass of a reference weight of a density of8000 kg/m3which it balances in air of density of 1.2 kg/m3.93.1.5.1 DiscussionFormerly known as apparent mass ver-sus 8.0 g/cm3.3.1.6 correctionmass values are traditionally expressedby two n
19、umbers, one being the nominal mass of the weight,and the second being a correction. The mass of the weight isthe assigned nominal value plus the assigned correction.Positive corrections indicate that the weight embodies moremass than is indicated by the assigned nominal value.3.1.7 international pro
20、totype kilogramthe platinum-iridium cylinder maintained at the International Bureau ofWeights and Measures (BIPM), at Sevres, France with aninternationally accepted defined mass of 1 kg.3.1.8 reference standarda standard, generally of the high-est metrological quality available at a given location,
21、fromwhich measurements made at that location are derived.103.1.9 set of weightsa series of weights, usually presentedin a case so arranged to make possible any weighing of allloads between the mass of the weight with the smallest nominalvalue and the sum of the masses of all weights of the serieswit
22、h a progression in which the mass of the smallest nominalvalue weight constitutes the smallest step of the series.63.1.10 tolerance (adjustment tolerance or maximum permis-sible errors)the maximum amount by which the conven-tional mass of the weight is allowed to deviate from theassigned nominal val
23、ue.3.1.11 tolerance testverification that the conventionalmass of the weights and their corresponding uncertainties astested are correct within the maximum permissible errors of therespective weight class.3.1.12 traceabilityproperty of the result of a measurementor the value of a standard whereby it
24、 can be related to statedreferences, usually national or international standards, throughan unbroken chain of comparisons all having stated uncertain-ties.73.1.12.1 DiscussionFor more information see 3.1.14.3.1.13 uncertaintyparameter associated with the result ofa measurement, that characterizes th
25、e dispersion of the valuesthat could reasonably be attributed to the measurand.8Therange of values within which the true value is estimated to lie.3.1.14 U.S. National prototype standardplatinumiridiumkilogram identified as K20, maintained at the National Instituteof Standards and Technology, with v
26、alue assigned relative tothe International Prototype Kilogram provides the UnitedStates access to the mass unit.3.1.15 weight (mass standard)a material measure ofmass, regulated in regard to its physical and metrologicalcharacteristics: shape, dimension, material, surface quality,nominal value, and
27、maximum permissible error.63.1.15.1 DiscussionNot to be confused with a gravita-tional force.4. Maximum Permissible Errors (Tolerances)4.1 For each weight, the expanded uncertainty U at 95 %confidence (See Annex B of OIML R 111) of the conventionalmass shall be less than or equal to one-third of the
28、 maximumpermissible error given in Table 1.4.1.1 For each weight, the conventional mass, mc(deter-mined with an expanded uncertainty), shall not differ by morethan the difference: maximum permissible error dm minusexpanded uncertainty, from the nominal value of the weight,mo:mo2 dm 2 U! # mc! #mo1 d
29、m 2 U! (1)4.2 Maximum permissible errors (tolerances) on verificationfor classes 0, 1, 2, 3, 4, 5, 6 and 7 are given in Table 1. Thesemaximum permissible errors are related to conventional massvalues.NOTE 1Consistent with OIML R 111 the concept of group toleranceshas been dropped in the 1997 revisio
30、n of this specification.NOTE 2Tolerances for weights of denominations intermediate be-tween those listed can be determined as follows. If the unit of measure isnon-metric use the conversion factor from the Abbreviations of Termstable in Appendix X3 to convert the nominal value to a metric unit. Forw
31、eights that are intermediate between those listed, the tolerance for thenext lower weight shall be applied.NOTE 3Class 0 is a new designation with tolerances that are 50 % ofClass 1, with physical characteristics the same as those of OIML R 111Class E1.NOTE 4Class 7 is a new designation with the sam
32、e tolerances as theformer Class T in NBS Circular 3 (out of print).5. Physical Characteristics5.1 Construction:5.1.1 TypeWeights are divided into two types based uponthe design:5.1.1.1 Type IThese weights are of one-piece constructionand contain no added adjusting material. They must bespecified whe
33、n weights are to be used as standards for thecalibration of weights of Classes 0, 1, 2 and 3, and wheremaximum stability is required. A precise measurement ofdensity can only be made for one-piece weights.5.1.1.2 Type IIWeights of this type can be of any appro-priate design such as screw knob, ring,
34、 or sealed plug.Adjusting material can be used as long as it is of a material atleast as stable as the base material and is contained in such away that it will not become separated from the weight.7Definition from International Vocabulary of Basic and General Terms inMetrology.8Definition from NCSL
35、Z-540-1-1994.9Definition from OIML R33.10Definition from NIST/NVLAP Handbook 150.E 617 97 (2008)25.1.2 Class 0 must be Type I, one piece construction.5.1.3 Class 1, 2, 3, 4, 5, 6 and 7 can be either Type I or TypeII depending on the application.5.2 DesignA weight may have any shape that does notintr
36、oduce features that reduce the reliability. All weights shallbe free of ragged or sharp edges or ends. Both sheet metal andwire weights shall be free of cracks such as may be formedfrom bending.5.3 Surface AreaFor classes 0, 1, 2, 3 and 4 the surfacearea is not to exceed twice the area of a cylinder
37、 of equal heightand diameter for weights 1 g and above. Sheet metal weights orwire weights may be used below 1 g.5.4 Material:5.4.1 Class 0, 1, 2 and 3 WeightsThe hardness of thismaterial and its resistance to wear and corrosion shall besimilar to or better than that of austenitic stainless steel.5.
38、4.2 Class 4, 5, 6 and 7The hardness and brittleness ofthe materials used for weights of Classes 4, 5, 6, and 7 shall beat least equal to that of drawn brass.5.5 MagnetismWeights shall not exceed maximum per-missible magnetic properties as listed in Table 2 for any portionof the weight:NOTE 5Cast iro
39、n cannot have a susceptibility specification of any realvalue.NOTE 6The measurement method is incorporated from OIMLR 111-2 (8th draft) in section A5.3.2, Susceptometer.5.6 DensityBecause of the effect of the buoyant force ofair on a weight, precision measurements of mass require thatthe volume of t
40、he weight be known, as well as the density ofthe air in which it is being measured, so that appropriatecorrections can be made. For weights of higher precision, therange of density is limited to values at or near the density ofwell-established standards, such as are used by primary cali-bration labo
41、ratories. As lower precision of measurement isrequired, so the range of density is broadened. See Table 3.NOTE 7Materials used to make weights for special applications thatTABLE 1 Maximum TolerancesDenominationASTM Tolerance Table 6mg except as notedClass 0 Class 1 Class 2 Class 3 Class 4 Class 5 Cl
42、ass 6 Class 75000 kg . . . . 100 g 250 g 500 g 750 g3000 kg . . . . 60 g 150 g 300 g 450 g2000 kg . . . . 40 g 100 g 200 g 300 g1000 kg . . . . 20 g 50 g 100 g 150 g500 kg . . . . 10 g 25 g 50 g 75 g300 kg . . . . 6.0 g 15 g 30 g 45 g200 kg . . . . 4.0 g 10 g 20 g 30 g100 kg . . . . 2.0 g 5 g 10 g 1
43、5 g50 kg 63 125 250 500 1.0 g 2.5 g 5 g 7.5 g30 kg 38 75 150 300 600 mg 1.5 g 3 g 4.5 g25 kg 31 62 125 250 500 1.2 g 2.5 g 4.5 g20 kg 25 50 100 200 400 1.0 g 2 g 3.8 g10 kg 13 25 50 100 200 500 mg 1 g 2.2 g5 kg 6 12 25 50 100 250 500 mg 1.4 g3 kg 3.8 7.5 15 30 60 150 300 1.0 g2 kg 2.5 5.0 10 20 40 1
44、00 200 750 mg1 kg 1.3 2.5 5.0 10 20 50 100 470500 g 0.60 1.2 2.5 5.0 10 30 50 300300 g 0.38 0.75 1.5 3.0 6.0 20 30 210200 g 0.25 0.50 1.0 2.0 4.0 15 20 160100 g 0.13 0.25 0.50 1.0 2.0 9 10 10050 g 0.060 0.12 0.25 0.60 1.2 5.6 7 .30 g 0.037 0.074 0.15 0.45 0.90 4.0 5 4420 g 0.037 0.074 0.10 0.35 0.70
45、 3.0 3 3310 g 0.025 0.050 0.074 0.25 0.50 2.0 2 215 g 0.017 0.034 0.054 0.18 0.36 1.3 2 133 g 0.017 0.034 0.054 0.15 0.30 0.95 2.0 9.42 g 0.017 0.034 0.054 0.13 0.26 0.75 2.0 7.01 g 0.017 0.034 0.054 0.10 0.20 0.50 2.0 4.5500 mg 0.005 0.010 0.025 0.080 0.16 0.38 1.0 3.0300 mg 0.005 0.010 0.025 0.070
46、 0.14 0.30 1.0 2.2200 mg 0.005 0.010 0.025 0.060 0.12 0.26 1.0 1.8100 mg 0.005 0.010 0.025 0.050 0.10 0.20 1.0 1.250 mg 0.005 0.010 0.014 0.042 0.085 0.16 0.50 0.8830 mg 0.005 0.010 0.014 0.038 0.075 0.14 0.50 0.6820 mg 0.005 0.010 0.014 0.035 0.070 0.12 0.50 0.5610 mg 0.005 0.010 0.014 0.030 0.060
47、0.10 0.50 0.45 mg 0.005 0.010 0.014 0.028 0.055 0.080 0.20 .3 mg 0.005 0.010 0.014 0.026 0.052 0.070 0.20 .2 mg 0.005 0.010 0.014 0.025 0.050 0.060 0.20 .1 mg 0.005 0.010 0.014 0.025 0.050 0.050 0.10 .TABLE 2 Magnetic PropertiesClassVolume MagneticSusceptibility (x)Maximum Magnetic FieldT mG0 0.01 2
48、.0 201 0.03 4.0 402, 3, 4 0.05 6.0 605, 6, 7AAAARequirements for these classes have not been developed.E 617 97 (2008)3do not fall within the density limits stated above, shall have densitydeterminations performed.5.7 FinishThe surface of the weights (including the baseand corners) shall be smooth,
49、the edges shall be rounded, andthe weights shall not be porous.5.7.1 The surface quality of a weight shall not exceedmaximum values of surface roughness, Raand Rzthroughvisual inspection using a hand held gage.2Reference 2.1. SeeTable 4.5.7.2 For weights with recessed areas for easier handling,the recessed area and handle should have a finish with surfaceroughness no greater than Rz= 0.67 m and RA= 0.05 m. Theouter diameter, top and bottom surface roughness must meetthe above table.5.8 Adjustment:5.8.1 Type I WeightsWeights shall be ad
