ASTM E617-2018 Standard Specification for Laboratory Weights and Precision Mass Standards.pdf

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1、Designation: E617 18Standard Specification forLaboratory Weights and Precision Mass Standards1This standard is issued under the fixed designation E617; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu

2、mber 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 000, 00, 0, 1, 2, 3, 4,5, 6, and 7. This s

3、pecification replaces National Bureau ofStandards Circular 547, Section 1, which is out of print.1.2 This specification and calibration method is intended foruse by weight manufacturers, national metrology institutes,weight calibration laboratories, accreditation bodies, users ofweights, and regulat

4、ory bodies.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 calibration of weights of a lower class ofaccuracy; and1.3.3 With weighing instruments.1.4 Maximu

5、m Permissible Errors (formerly tolerances) anddesign restrictions for each class are described in order thatboth individual weights or sets of weights can be chosen forappropriate applications.1.5 Weight manufacturers must be able to provide evidencethat all new weights comply with specifications in

6、 this standard(for example, material, density, magnetism, surface finish,mass values, uncertainties). Statements of compliance bycalibration laboratories during subsequent calibrations mustmeet the requirements of ISO/IEC 17025, 5.10.4.2 and indicateon the calibration report which sections have or h

7、ave not beenassessed. Subsequent calibrations must meet all the require-ments (including environmental parameters as shown inTable 11, of Sections 7, 8, and 9; and the requirements ofISO/IEC 17025:2005, 5.10.4.2 to make any claim of compli-ance to Specification E617, Maximum Permissible Errors,weigh

8、t classes, or metrological traceability.1.6 The values stated in SI units are to be regarded asstandard.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of Internat

9、ional Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ISO Standards:2ISO/IEC 17025 General Requirements for the Competenceof Testing and Calibration Laboratories (2005)2.2 NIST Standards:3NIST Handboo

10、k 143 State Weights and Measures Laborato-ries Program Handbook (2007)NIST SP 811 Guide for the Use of the International Systemof Unit (SI) 2008 EditionNIST SP 1038 The International System of Units (SI) Conversion Factors for General Use (May 2006)NISTIR 5672 Advanced Mass Calibration and Measureme

11、ntAssurance Program for State Calibration Laboratories(2014)NISTIR 6969 Selected Laboratory and Measurement Prac-tices to Support Basic Mass Calibrations (2017)NIST Technical Note 1297 (1994) Guidelines for Evaluatingand Expressing the Uncertainty of NIST MeasurementResults2.3 OIML Standards:4OIMLD

12、28 Conventional Value of the Result of Weighing inAir (2004)OIML R1111e04 Weights of classes E1, E2, F1, F2, M1,M12, M2, M23 and M3 Part 1: Metrological andTechnical Requirements (2004)2.4 BIPM Standards:5VIM: JCGM 200:2012 International Vocabulary of Metrolo-gyBasic and General Concepts and Associa

13、ted Terms1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatusand is the direct responsibility of Subcommittee E41.06 onLaboratory Instruments and Equipment.Current edition approved Oct. 1, 2018. Published November 2018. Originallyapproved in 1978. Last previous

14、edition approved in 2013 as E617 13. DOI:10.1520/E0617-18.2Available from International Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http:/www.iso.org.3Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop

15、 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.4Available from Organisation Internationale de Metrologie Legale, 11 RueTurgot, 75009 Paris, France, http:/www.oiml.org.5Available from Bureau International des Poids et Mesures (BIPM), Pavilion deBreteuil, F-92312, Svres Cedex, France, http:/ww

16、w.bipm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopme

17、nt of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1GUM: JCGM 100:2008 Evaluation of MeasurementDataGuide to the Expression of Uncertainty in Measure-ment2.5 EURAMET Standards:6EURAMET/cg-18/V. 4.0 Guidelines o

18、n the Calibration ofNon-Automatic Weighing Instruments (2015)3. 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.3.1.2 balanceinstrument indic

19、ating apparent mass that issensitive to the following forces:Fg5 mgForce due to gravityFb5 vag 5magAir buoyancy equal to the weight ofthe displaced air.Fz5 oeeevsM 1 Hd H zdVVertical component of the magneticinteraction between the weight andthe balance or the environment, orboth.H and M are vectors

20、; z is the vertical cartesian coordinate.If magnetic effects are negligible, that is, the permanentmagnetization (M) of the weight and the magnetic suscepti-bility () are sufficiently small, and the balance is calibratedwith reference weights of well-known mass, the balance canbe used to indicate th

21、e conventional mass, mc, of a bodyunder conventionally chosen conditions.3.1.3 calibration (of weights)the acts of determining themass difference between a standard of known mass value andan “unknown” test weight or set of weights, establishing themass value and conventional mass value of the “unkno

22、wn,”and of determining a quantitative estimate of the uncertainty tobe assigned to the stated mass or conventional mass value ofthe “unknown,” or both, and providing metrological traceabil-ity to the “unknown.”3.1.3.1 calibration (generally)set of operations thatestablish, under specified conditions

23、, the relationship betweenvalues of quantities indicated by a measuring instrument ormeasuring system, or values represented by a material measureor a reference material, and the corresponding values realizedby standards.3.1.4 calibration certificatecertificate issued by calibra-tion laboratories to

24、 document the results of a calibration.3.1.5 conventional massconventional value of the resultof weighing in air, in accordance to International Recommen-dation OIML D 28. 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 i

25、n air of density of 1.2 kg/m3.3.1.6 correctionmass values are traditionally expressed bytwo numbers, one being the nominal mass of the weight, andthe second being a correction. The mass of the weight is theassigned nominal value plus the assigned correction. Positivecorrections indicate that the wei

26、ght embodies more mass thanis indicated by the assigned nominal value. Negative correc-tions indicate that the weight embodies less mass than isindicated by the assigned nominal value. The correction isequivalent to the “error.”3.1.7 international prototype kilogramthe platinum-iridium cylinder main

27、tained at the International Bureau ofWeights and Measures (BIPM), at Sevres, France with aninternationally accepted defined mass of 1 kg.3.1.8 magnetismeffect that generates an attractive or re-pulsive force.3.1.8.1 (volume) magnetic susceptibility ()measure of theability of a medium to modify a mag

28、netic field. It is related tothe magnetic permeability () by the relation: /0=1+. Thequantity /0is sometimes referred to as the relativepermeability, r.3.1.8.2 (permanent) magnetization (M)parameter thatspecifies a magnetic state of material bodies such as weights, inthe absence of an external magne

29、tic field (most generally,magnetization is a vector whose magnitude and direction arenot necessarily constant within the material). The magnetiza-tion of a body generates an inhomogeneous magnetic field inspace and thus may produce magnetic forces on other materi-als.3.1.9 massphysical quantity, whi

30、ch can be ascribed to anymaterial object and which gives a measure of its quantity ofmatter. The unit of mass is the kilogram.3.1.10 maximum permissible errorsthe maximum amountby which the sum of the conventional mass of the weight, itsdeviation from nominal value, and its associated uncertainty is

31、allowed to deviate from the assigned nominal value.3.1.11 metrological traceabilityproperty of a measure-ment result whereby the result can be related to a referencethrough a documented unbroken chain of calibrations, eachcontributing to the measurement uncertainty. Metrologicaltraceability requires

32、 an established calibration hierarchy. Ele-ments for confirming metrological traceability to be an unbro-ken chain to an international measurement standard or anational measurement standard (IPK or NPS), shall include adocumented measurement uncertainty, a documented measure-ment procedure, accredit

33、ed technical competence, metrologicaltraceability to the SI, and established calibration intervals (seecurrent VIM: JCGM 200).3.1.12 reference standarda standard, generally of thehighest metrological quality available at a given location, fromwhich measurements made at that location are derived.3.1.

34、13 roughness parameter or R-parameter (Raor Rz)parameter that describes the assessed roughness profile of asample. The letter R is indicative of the type of assessedprofile, in this case R for roughness profile. The assessedprofile of a sample can be in terms of different profile types: aroughness p

35、rofile or R-parameter, primary profile orP-parameter, a waviness profile or W-parameter.3.1.14 set of weightsa series of weights, usually presentedin a case so arranged to make possible any weighing of all6Available from Euramet, Bundesallee 100, 38116 Braunschweig, Germany,http:/www.euramet.org.E61

36、7 182loads between the mass of the weight with the smallest nominalvalue and the 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.3.1.15 temperature (t)in degrees Celsius, is related to

37、theabsolute thermodynamic temperature scale, called the Kelvinscale, by t=T 273.15 K.3.1.16 test weight (mt)weight that is to be tested accordingto this standard.3.1.17 tolerance testverification that the conventionalmass of the weights and their corresponding uncertainties astested are correct with

38、in the maximum permissible errors of therespective weight class.3.1.18 uncertaintynon-negative parameter characterizingthe dispersion of the quantity values being attributed to ameasurand, based on the information used.3.1.19 unitsthe units used are: (1) for mass, the milligram(mg), the gram (g) and

39、 the kilogram (kg); (2) for density, thekilogram per cubic meter (kg m3).3.1.20 U.S. National prototype standardplatinum-iridiumkilogram identified as K20, maintained at the National Instituteof Standards and Technology, with value assigned relative tothe International Prototype Kilogram provides th

40、e UnitedStates access to the mass unit.3.1.21 weightmaterial measure of mass, regulated in re-gard to its physical and metrological characteristics: shape,dimensions, material, surface quality, nominal value, density,magnetic properties and maximum permissible error.NOTE 1The term “weight” is also u

41、sed as the physical quantity of thegravitational force of a body. From the context it is usually clear in whichsense the term is used. If the sense is not clear, one may use the words“weight force” or “weight piece,” depending on its meaning.3.2 Symbols:Symbol Unit DefinitionA represents weighing th

42、e referenceweight in a weighing cycleB represents weighing the test weight ina weighing cycleC correction factor for air buoyancyD kg difference of balance readingsbetween minimum and maximumvalues from eccentricity testd kg scale intervald1m estimated distance between centers ofweights during loadi

43、ngd2m estimated distance from the center ofthe load receptor to one of the cornersFbN air buoyancy equal to the weight of thedisplaced airFgN gravitational forceFzN magnetic force between a masscomparator and a weight in the verticalor z-directiong ms2gravitational accelerationH Am1magnetizing field

44、 strengthhr % relative humidityI kg indication of the weighing instruments(scale division)I kg indication difference of the balance,where I = ItIrI1kg indication difference using anautomatic exchange mechanism withweights in first positionSymbol Unit DefinitionI2kg indication difference using anauto

45、matic exchange mechanism withweights in reversed positionIskg change in indication of balance due tosensitivity weighti subscript used as an index insummationsj subscript for number of test weights ornumber of series of measurementsk coverage factor, typically 2 or 3M Am1permanent magnetization (see

46、 also0M)m kg mass of a rigid body (weight)m kg mass difference, usually between testand reference weightm kg maximum permissible error on theweightsm0kg mass, nominal value of the weight(e.g. 1 kg)mckg conventional mass of the weightmckg conventional mass difference betweentest weight and reference

47、weightmckg average conventional mass differencebetween test weight and referenceweightmcrkg conventional mass of the referenceweightmctkg conventional mass of the test weightmskg mass of the sensitivity weightmtkg mass of the test weightn subscript for number of measurementsequencesp Pa barometric p

48、ressureRam mean height of roughness profile (R-parameter)Rzm maximum height of roughness profile(R-parameter)r subscript for reference weights subscript for sensitivity weights kg standard deviations2kg2varianceT K thermodynamic temperature using theInternational Temperature Scale of1990 (ITS-90)T*

49、C initial difference between weight tem-perature and laboratory temperaturet subscript for test weightt C temperature in degrees Celsius, wheret = T 273.15 KU kg uncertainty, expanded uncertaintyu kg uncertainty, standard uncertaintyubkg uncertainty of air buoyancy correctionubakg uncertainty of the balanceuckg combined standard uncertaintyudkg uncertainty due to the display resolu-tion of a digital balanceuEkg uncertainty due to eccentricityuFkg m3uncertainty of the formula used to