1、Designation: E 617 97 (Reapproved 2003)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 (e) 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 a
3、nd7. 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 sp
4、ecification, 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 we
5、ighing 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 ASTM Standards:B 46.
6、1-1995 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, Switzerland3Guide to the Expression of Uncertainty in Measurement3ISO/DIS 4287-1, Edition 01-Jun-95, Geome
7、tric ProductSpecification (GPS), Determination of Surface Texture byProfiling Methods, Part 1: Terms, Definitions and Param-eters32.3 NCSL Standards:NCSL Glossary of MetrologyRelated Terms4NCSL Recommended Practice-12 Determining and Report-ing Measurement Uncertainties4ANSI/NCSL-Z540-1-1994 America
8、n National Standard forCalibration-Calibration Laboratories and Measuring andTest Equipment General Requirements42.4 NIST Standards:NIST NVLAP Draft Handbook 150-2 National VoluntaryLaboratory Accreditation Program Calibration Laborato-ries Technical Guide5NIST NVLAP Handbook 150 National Voluntary
9、Labora-tory Accreditation Program (NVLAP), NIST Handbook150, Procedures and General Requirements5NIST Technical Note 1297 (1994) Guidelines for Evaluat-ing and Expressing the Uncertainty of NIST MeasurementResults52.5 OIML Standard:OIML Recommendation 33 Conventional Value of the Re-sult of Weighing
10、 in Air63. 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.73.1.2 calibrationthe acts of determining the mass differ-ence between a standard
11、of 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 be1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatus,
12、and is the direct responsibility of Subcommittee E41.06 onWeighing Devices.Current edition approved Nov. 10, 1997. Published March 1998. Originallypublished as E 617 78. Last previous edition E 617 91.2Available from ASME Service Center, 22 Law Drive, PO Box 2900, Fairfield,New Jersey 07007-2900.3Av
13、ailable from American National Standards Institute, 11 West 42nd Street,New York, New York 10036.4Available from NCSL, National Conference of Standards Laboratories, 180030th Street, Suite 305B, Boulder, Colorado 80301.5Available from NIST/NVLAP, National Voluntary Laboratory AccreditationProgram, N
14、IST, 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.6Available from Organisation Internationale de Metrologie Legale, 11 RueTurgot, 75009 Paris, France.7Definition from OIM
15、L R111.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.assigned to the stated mass or conventional mass value of the“unknown”, or both. Set of operations that establish, underspecified conditions, the relationship between values of q
16、uan-tities indicated by a measuring instrument or measuring sys-tem, or values represented by a material measure or a referencematerial, and the corresponding values realized by standards.83.1.3 certificate of tolerance testdocument that certifiesthat the subject weights are within specified toleran
17、ces.3.1.3.1 DiscussionIf traceability is claimed, some level ofuncertainty must be addressed.3.1.4 certificate or report of calibrationdocument thatpresents calibration results and other information relevant to acalibration.93.1.5 conventional massconventional value of the resultof weighing in air,
18、in accordance to International Recommen-dation OIML 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/m3.103.1.5.1 DiscussionFormerly known as apparent mass ver-sus 8.0 g/cm3.3.1.6 correcti
19、onmass values are traditionally expressedby two numbers, 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 t
20、he assigned nominal value.3.1.7 international prototype 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 met
21、rological quality available at a given location, fromwhich measurements made at that location are derived.113.1.9 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
22、sum of the masses of all weights of the serieswith a progression in which the mass of the smallest nominalvalue weight constitutes the smallest step of the series.73.1.10 tolerance (adjustment tolerance or maximum permis-sible errors)the maximum amount by which the conven-tional mass of the weight i
23、s allowed to deviate from theassigned nominal value.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
24、 measurementor the value of a standard whereby it can be related to statedreferences, usually national or international standards, throughan unbroken chain of comparisons all having stated uncertain-ties.83.1.12.1 DiscussionFor more information see 3.1.14.3.1.13 uncertaintyparameter associated with
25、the result ofa measurement, that characterizes the dispersion of the valuesthat could reasonably be attributed to the measurand.9Therange 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 Nati
26、onal Instituteof Standards and Technology, with value 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, dimensi
27、on, material, surface quality,nominal value, and maximum permissible error.73.1.15.1 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 conventionalmas
28、s shall be less than or equal to one-third of the 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 nomina
29、l value of the weight,mo:mo2 dm 2 U! # mc! # mo1 dm 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 gr
30、oup toleranceshas been dropped in the 1997 revision 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 t
31、o convert the nominal value to a metric unit. Forweights 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
32、E1.NOTE 4Class 7 is a new designation with the same 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 a
33、dded adjusting material. They must bespecified when 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
34、 any appro-priate design such as screw knob, ring, or sealed plug.Adjusting material can be used as long as it is of a material at8Definition from International Vocabulary of Basic and General Terms inMetrology.9Definition from NCSL Z-540-1-1994.10Definition from OIML R33.11Definition from NIST/NVLA
35、P Handbook 150.E 617 97 (2003)2least as stable as the base material and is contained in such away that it will not become separated from the weight.5.1.2 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
36、DesignA weight may have any shape that does notintroduce 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 surfac
37、earea is not to exceed twice the area of a cylinder 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 o
38、r better than that of austenitic stainless steel.5.4.2 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
39、Table 2 for any portionof the weight:NOTE 5Cast iron 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, precisi
40、on measurements of mass require thatthe volume of the 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, theTABLE 1 Maximum TolerancesDenominationASTM Tolerance Table 6mg except as notedClass 0
41、 Class 1 Class 2 Class 3 Class 4 Class 5 Class 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
42、 g 20 g 30 g100 kg . . . . 2.0 g 5 g 10 g 15 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
43、 30 60 150 300 1.0 g2 kg 2.5 5.0 10 20 40 100 200 750 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
44、.90 4.0 5 4420 g 0.037 0.074 0.10 0.35 0.70 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
45、 0.38 1.0 3.0300 mg 0.005 0.010 0.025 0.070 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.
46、50 0.5610 mg 0.005 0.010 0.014 0.030 0.060 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 MagneticSusceptib
47、ility (x)Maximum Magnetic FieldT mG0 0.01 2.0 201 0.03 4.0 402, 3, 4 0.05 6.0 605, 6, 7AAAARequirements for these classes have not been developed.E 617 97 (2003)3range of density is limited to values at or near the density ofwell-established standards, such as are used by primary cali-bration labora
48、tories. 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 thatdo not fall within the density limits stated above, shall have densitydeterminations performed.5.7 FinishThe surface of the weight
49、s (including the baseand corners) shall be smooth, 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
