1、Designation: D 4753 07Standard Guide forEvaluating, Selecting, and Specifying Balances andStandard Masses for Use in Soil, Rock, and ConstructionMaterials Testing1This standard is issued under the fixed designation D 4753; the number immediately following the designation indicates the year oforigina
2、l adoption or, in the case of revision, the year of 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. Scope*1.1 This guide provides minimum requirements for general-purpose sca
3、les, balances, and standard masses used in testingsoil, rock, and related construction materials.1.2 This guide provides guidance for evaluating, selecting,and specifying general purpose scales, balances, and standardmasses used in testing soil, rock, and related constructionmaterials.1.3 The accura
4、cy requirements for balances and scales arespecified in terms of the combined effect of all sources of errorcontributing to overall balance performance. The measurementof specific sources of error and consideration of detailspertaining to balance construction have been intentionallyavoided.1.4 This
5、guide does not include requirements for balancesand scales having accuracies greater than those generallyrequired in testing soil, rock, and related construction materialsor for research programs or specialized testing requirements.1.5 This guide does not apply to nongraduated balances.1.6 This guid
6、e does not address the methods used to verifyor quantify specific parameters dealing with balances andscales. For a description of tests used in evaluating balanceperformance, see NIST Handbook 44.1.7 This guide is not intended to be used as a specificationfor the purchase of balances and scales.NOT
7、E 1The National Institute of Standards and Technology (NIST),formerly the National Bureau of Standards (NBS), and the InternationalOrganization of Legal Metrology (OIML) publish standards or practicesthat specify construction requirements as well as performance guides forbalances. ASTM, OIML, and NI
8、ST publish construction standards andtolerances for standard masses.NOTE 2The terms “mass” and “determine the mass of” are used inthis standard instead of the more commonly used terms “weight” and“weigh” to comply with standard metric practice. In addition, the term“standard mass(es)” is used instea
9、d of standard “standard weight(s)” whenreferring to a piece of material of known specified mass used to compareor measure the mass of other masses.1.8 This guide offers an organized collection of informationor a series of options and does not recommend a specificcourse of action. This document canno
10、t replace education orexperience and should be used in conjunction with professionaljudgement. Not all aspects of this guide may be applicable inall circumstances. This ASTM standard is not intended torepresent or replace the standard of care by which theadequacy of a given professional service must
11、 be judged norshould this document be applied without consideration of aprojects many unique aspects. The word “Standard” in thetitle of this document means only that the document has beenapproved through the ASTM consensus process.2. Referenced Documents2.1 ASTM Standards:2D 653 Terminology Relatin
12、g to Soil, Rock, and ContainedFluidsE 617 Specification for Laboratory Weights and PrecisionMass Standards2.2 National Institute of Standards and Technology Docu-ments:NIST Handbook 44 Specifications, Tolerances, and OtherTechnical Requirements for Weighing and MeasuringDevices32.3 International Org
13、anization for Legal Metrology(OIML):International Recommendation No. 20 Weights of Accu-racy Classes E1,E2,F1,F2,M1from 50 kg to 1 mg4International Recommendation No. 343. Terminology3.1 Definitions: For definitions of terms used in this guiderefer to Terminology D 653.1This guide is under the juris
14、diction ofASTM Committee D18 on Soil and Rockand is the direct responsibility of Subcommittee D18.91 on Standards Developmentand Review.Current edition approved July 15, 2007. Published August 2007. Originallyapproved in 1987. Last previous edition approved in 2002 as D 4753 02.2For referenced ASTM
15、standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from National Institute of Standards and Technology (NIST), 100Bureau D
16、r., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.4Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.1*A Summary of Changes section appears at the end of this standard.Copyrig
17、ht ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2 Definitions of Terms Specific to This Standard:3.2.1 accuratea balance is “accurate” when its perfor-mance (its indication as determined by tests made with suitablestandards) conforms to th
18、e standard within the applicabletolerances and other performance requirements. Balances thatfail to conform are “inaccurate.”3.2.2 balancean instrument for determining the mass ofan object by the action of gravity on the object. See scale.3.2.2.1 DiscussionIn this guide and in common usage, theterms
19、 balance and scale are used interchangeably. The termbalance is more often used in scientific fields of application.The term scale usually refers to instruments intended forcommercial or industrial applications, and when so used,usually implies an instrument of lesser performance than abalance.3.2.3
20、 basic conditiona condition that must be met beforea basic measurement for evaluating a balance can be per-formed.3.2.4 basic measurement (of error)a basic measurementfor evaluating a balance is performed by (1) determining thechange of indication of the balance when a known mass isadded to or subtr
21、acted from any mass already on the balance;and (2) taking the difference between the change in theindication determined and the known value of the mass.3.2.5 basic tolerancetolerances that are established by aparticular code for a particular device under all normal tests,whether maintenance or accep
22、tance. Basic tolerances includeminimum tolerance values when these are specified. Specialtolerances, identified as such and pertaining to special tests, arenot basic tolerances.3.2.6 capacityof a balance, the maximum mass recom-mended by the manufacturer, disregarding any additionalcapability suppli
23、ed by a taring device.3.2.7 general-purpose balanceany balance used to makea general purpose determination of mass. See general-purposedetermination of mass.3.2.8 general-purpose determination of massa single de-termination of mass using a balance (not a special purposedetermination of mass involvin
24、g repeat determinations ofmass, averages, standard deviations, corrections, etc.).3.2.9 general-purpose standard massa standard massused with a balance to make a general purpose determination ofmass. See general-purpose determination of mass.3.2.10 hysteresisthe difference between successive mea-sur
25、ements of a standard mass when the standard mass ismeasured after a cycle of adding, and then removing (orremoving, then adding) mass from the balance.3.2.11 linearity errorplus or minus deviation from thetheoretically straight-lined (linear) course of two interdepen-dent values. In balances, this e
26、xpression is applied to the plusor minus deviation of the indicated measurement value fromthe true (actual) value of the mass.3.2.11.1 DiscussionLinearity implies that the deviationfrom the true values are a continuous function of the appliedmass. Thus, obtaining enough values of the true applied ma
27、ssversus balance reading to establish a relation between appliedmass and output should give the error that will occur at anyapplied mass. Linearity, then, is a statement about the system-atic (nonrandom) error of a balance. Superimposed on thelinearity are precision and other effects, such as off-ce
28、ntererrors, temperature effects, etc. Linearity is a measure ofbalance performance over its full range, and on most balancesadjustments can be made to alter the useableness of a balancewith a given linearity for measurements within a particularrange of use.3.2.12 nongraduated balancebalances not fit
29、ted with ascale numbered in units of mass.3.2.13 off-center errorof a top loading or platform bal-ance, the difference in indicated value when a mass is shiftedto various positions on the loading area (pan or platform);eccentric load error.3.2.13.1 DiscussionThe test for off-center error is calledth
30、e shift test, or offcenter-load test. Information about balanceperformance under eccentric loadings is not normally found inproduct literature but such information can usually be obtainedby contacting the manufacturer directly.3.2.14 precision of a balancethe degree of agreementbetween the indicatio
31、ns of a balance for repeated determina-tions of mass of the same mass under essentially the sameconditions. It is usually expressed quantitatively as a standarddeviation of a series of mass determinations, or as a function ofthe range of several mass determinations. See repeatabilitytype II, reprodu
32、cibility.3.2.15 readability type Ithe value of the smallest unit ofmass that can be read without estimation over the given rangeof measurement either directly or by use of a vernier ormicrometer.3.2.16 readability type IIthe value of the smallest unit ofmass that can be read with estimation over the
33、 given range ofmeasurement.3.2.17 readability type IIIthe value of the smallest unit ofmass that can be read when in-service conditions such as draft,vibration, and other environmental conditions affect the bal-ance while the balance is in use, but not smaller thanreadability Type I.3.2.18 repeatabi
34、lity type Ithe degree of agreement be-tween the indications of a balance for repeated determinationsof the same mass under essentially the same conditions. Thedegree of agreement (qualitatively).3.2.19 repeatability type IIsee precision of a balance.3.2.20 reproducibilitysee precision of a balance.3
35、.2.21 scalesee balance.3.2.22 sensitivitythe ratio of the deflection (DL)ofthebalance indicator or self-indicating display to the mass (DM)causing the deflection; S = DL/DM at a given mass.NOTE 3Values for sensitivity are sometimes seen expressed in termsof mass units. When used in this way in refer
36、ence to a nonself-indicatingbalance, sensitivity refers to the reciprocal of sensitivity or the change inmass required to change the position of equilibrium (rest point) a specifiedamount, usually one division on the balance indicator. When used inreference to self-indicating balances, it refers to
37、the change in massrequired to change the indication by one scale division.3.2.23 standard massan object of specified mass andconstruction used with balances, and for the verification ofbalances and other masses.D47530723.2.24 taring rangea range within which it is possible toreset the indicator or d
38、isplay to zero by use of the tare device.3.2.25 tolerancea value fixing the limit of allowable erroror departure from true performance or value.NOTE 4For additional terms used in this guide related to balances andstandard masses, see NIST Handbook 44 or OIML IR No. 3.4. Significance and Use4.1 This
39、guide provides those using standards related to soil,rock, and related construction materials, with a means forselecting the balance required for a particular standard.4.2 This guide provides those writing standards pertainingto soil, rock, and related construction materials with a meansfor specifyi
40、ng the balance capabilities required for a particularstandard and for describing the balance selected in a uniformfashion.4.3 This guide provides agencies conducting soil, rock, andrelated construction materials, testing with guidance for select-ing and evaluating general purpose balances and standa
41、rdmasses.4.4 This guide provides inspection organizations with crite-ria for evaluating general purpose balances and standardmasses.5. Requirements for General-Purpose Balances5.1 General-purpose balances shall be judged accurate for agiven class if their indications meet the basic tolerances showni
42、n Table 1.6. Requirements for General-Purpose Masses6.1 General-purpose standard masses for use in verificationbalances and testing of soil and rock shall conform to therequirements in Specification E 617 for Type I or Type II,Grade S, O, or P standard masses and have tolerance limitsequal to or bet
43、ter than those for Class 6 standard masses exceptthat the maintenance tolerances given in Specification E 617for Class 6 standard masses are to be considered acceptancetolerances for purposes of this guide and the maintenancetolerances twice those values. The tolerances values given inTable 2 corres
44、pond to the minimum acceptable maintenancetolerances under this guide.NOTE 5Former NIST Class J, M, S, S-1, P, and Q standard massesmeet this guide, as do OIML Class M1standard masses (IR No. 20).7. Evaluation of General-Purpose Balances7.1 Basic ToleranceTable 1 shows the basic tolerances forall cl
45、asses of general-purpose balances used in soil or rocktesting that are covered by this guide. The basic tolerancesshown apply to basic measurements made when evaluating abalance.7.1.1 A basic measurement for evaluating a balance isperformed by determining the change of indication of thebalance when
46、a known mass is added to or subtracted from anymass already on the balance, and then taking the differencebetween the change in the indication determined and theknown value of the mass. To evaluate a balance, the basictolerances shown in Table 1 are applied to the known value ofthe mass used in the
47、basic measurement. The result of a basicmeasurement must fall within the error allowed by the basictolerance.NOTE 6For nearly all determinations of mass encountered in soilstesting, the value of interest is the difference between two determinationsof mass. In cases where the difference between the t
48、wo determinations ofmass is small, relative to the total masses determined, it is desirable tospecify a tolerance based on the difference between the two determina-tions of mass to relieve what might otherwise be an excessively stringenttolerance.NOTE 7Ano load condition may be treated as a mass of
49、0.0 g and maybe considered a mass on the balance.7.1.2 The basic tolerance for a balance should apply to allvalues of loading within the range of the balance withoutregard to whether the balance is properly zeroed or a tare massis being used, and should apply under all usual and customarymethods of operation. Furthermore, the basic tolerance must bemet in the environment in which the balance is to be used.7.1.3 A balance shall not be considered acceptable if theresult of basic measurements involving any combination ofpoise locations, counterpoise
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