ASTM E617-97(2008)
(Specification)Standard Specification for Laboratory Weights And Precision Mass Standards
Standard Specification for Laboratory Weights And Precision Mass Standards
ABSTRACT
This specification covers laboratory weights and precision mass standards including their principal physical characteristics and metrological requirements. Maximum permissible error, magnetic property, density, and surface roughness for each weight shall be within the limits indicated in this specification. Physical characteristics shall be based on construction, design, surface area, materials, magnetism, density, surface finish, weight adjustment, and marking.
SCOPE
1.1 This specification covers weights and mass standards used in laboratories, specifically classes 0, 1, 2, 3, 4, 5, 6 and 7. This specification replaces National Bureau of Standards Circular 547, Section 1, which is out of print.
1.2 This specification further recognizes that International Recommendation R111 exists, that describes classes E1, E2, F1, F2, M1, M2 and M3. Users may choose to reference either R111 or this specification, depending on requirements.
1.3 This specification contains the principal physical characteristics and metrological requirements for weights that are used.
1.3.1 For the verification of weighing instruments;
1.3.2 For the verification of weights of a lower class of accuracy; and
1.3.3 With weighing instruments.
1.4 Tolerances and design restrictions for each class are described in order that both individual weights or sets of weights can be chosen for appropriate applications.
1.5 The values stated in SI units are to be regarded as the standard.
General Information
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Designation:E617 −97(Reapproved 2008)
Standard Specification for
Laboratory Weights and Precision Mass Standards
This standard is issued under the fixed designation E617; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2.3 NCSL Standards:
NCSL Glossary of Metrology—Related Terms
1.1 This specification covers weights and mass standards
NCSL Recommended Practice-12 Determining and Report-
used in laboratories, specifically classes 0, 1, 2, 3, 4, 5, 6 and
ing Measurement Uncertainties
7. This specification replaces National Bureau of Standards
ANSI/NCSL-Z540-1-1994 American National Standard for
Circular 547, Section 1, which is out of print.
Calibration-Calibration Laboratories and Measuring and
1.2 This specification further recognizes that International 3
Test Equipment General Requirements
Recommendation R111 exists, that describes classes E1, E2,
2.4 NIST Standards:
F1, F2, M1, M2 and M3. Users may choose to reference either
NIST NVLAP Draft Handbook 150-2 National Voluntary
R111 or this specification, depending on requirements.
Laboratory Accreditation Program Calibration Laborato-
1.3 This specification contains the principal physical char- ries Technical Guide
acteristics and metrological requirements for weights that are NIST NVLAP Handbook 150 National Voluntary Labora-
used. tory Accreditation Program (NVLAP), NIST Handbook
1.3.1 For the verification of weighing instruments; 150, Procedures and General Requirements
1.3.2 For the verification of weights of a lower class of NISTTechnical Note 1297 (1994) Guidelines for Evaluating
accuracy; and and Expressing the Uncertainty of NIST Measurement
1.3.3 With weighing instruments. Results
2.5 OIML Standard:
1.4 Tolerances and design restrictions for each class are
OIML Recommendation 33 Conventional Value of the Re-
described in order that both individual weights or sets of
sult of Weighing in Air
weights can be chosen for appropriate applications.
1.5 The values stated in SI units are to be regarded as the
3. Terminology
standard.
3.1 Definitions of Terms Specific to This Standard:
3.1.1 accuracy class of weights—a class of weights that
2. Referenced Documents
meets certain metrological requirements intended to keep the
2.1 ANSI Standard:
errors within specified limits.
B 46.1-1995 Surface Texture (Surface Roughness,
3.1.2 calibration—the acts of determining the mass differ-
Waviness, and Lay) an American National Standard
ence between a standard of known mass value and an “un-
2.2 ISO Standards:
known” test weight or set of weights, establishing the mass
International Vocabulary of Basic and General Terms in
value and conventional mass value of the “unknown”, and of
Metrology 1993, VIM, Geneve, Switzerland
determining a quantitative estimate of the uncertainty to be
Guide to the Expression of Uncertainty in Measurement
assigned to the stated mass or conventional mass value of the
ISO/DIS 4287-1, Edition 01-Jun-95, Geometric Product
“unknown”, or both. Set of operations that establish, under
Specification (GPS), Determination of Surface Texture by
specified conditions, the relationship between values of quan-
Profiling Methods, Part 1: Terms, Definitions and Param-
tities indicated by a measuring instrument or measuring
eters
Available from NCSL, National Conference of Standards Laboratories, 1800
This specification is under the jurisdiction of ASTM Committee E41 on 30th Street, Suite 305B, Boulder, Colorado 80301.
Laboratory Apparatusand is the direct responsibility of Subcommittee E41.06 on Available from NIST/NVLAP, National Voluntary Laboratory Accreditation
Weighing Devices. Program, NIST, Gaithersburg, Maryland 20899. HB 150 available on-line: http://
Current edition approved Dec. 1, 2008. Published February 2009. Originally ts.nist.gov/nvlap and Technical Note 1297 available on-line: http://physics.nist.gov/
approved in 1978. Last previous edition approved in 2003 as E617 – 97 (2003). Pubs/guidelines/outline.html.
DOI: 10.1520/E0617-97R08. Available from Organisation Internationale de Metrologie Legale, 11 Rue
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St., Turgot, 75009 Paris, France.
4th Floor, New York, NY 10036, http://www.ansi.org. Definition from OIML R111.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E617−97 (2008)
system, or values represented by a material measure or a 3.1.13 uncertainty—parameter associated with the result of
reference material, and the corresponding values realized by a measurement, that characterizes the dispersion of the values
7 8
standards. that could reasonably be attributed to the measurand. The
range of values within which the true value is estimated to lie.
3.1.3 certificate of tolerance test—document that certifies
that the subject weights are within specified tolerances. 3.1.14 U.S. National prototype standard—platinumiridium
3.1.3.1 Discussion—If traceability is claimed, some level of kilogramidentifiedasK20,maintainedattheNationalInstitute
uncertainty must be addressed. of Standards and Technology, with value assigned relative to
the International Prototype Kilogram provides the United
3.1.4 certificate or report of calibration—document that
States access to the mass unit.
presents calibration results and other information relevant to a
calibration. 3.1.15 weight (mass standard)—amaterialmeasureofmass,
regulated in regard to its physical and metrological character-
3.1.5 conventional mass—conventional value of the result
istics: shape, dimension, material, surface quality, nominal
of weighing in air, in accordance to International Recommen-
value, and maximum permissible error.
dation OIML R 33. For a weight taken at 20°C, the conven-
3.1.15.1 Discussion—Not to be confused with a gravita-
tional mass is the mass of a reference weight of a density of
3 3 9
tional force.
8000 kg/m which it balances in air of density of 1.2 kg/m .
3.1.5.1 Discussion—Formerly known as apparent mass ver-
3 4. Maximum Permissible Errors (Tolerances)
sus 8.0 g/cm .
4.1 For each weight, the expanded uncertainty U at 95 %
3.1.6 correction—massvaluesaretraditionallyexpressedby
confidence (SeeAnnex B of OIML R 111) of the conventional
two numbers, one being the nominal mass of the weight, and
mass shall be less than or equal to one-third of the maximum
the second being a correction. The mass of the weight is the
permissible error given in Table 1.
assigned nominal value plus the assigned correction. Positive
4.1.1 For each weight, the conventional mass, m (deter-
corrections indicate that the weight embodies more mass than c
mined with an expanded uncertainty), shall not differ by more
is indicated by the assigned nominal value.
than the difference: maximum permissible error δm minus
3.1.7 international prototype kilogram—the platinum-
expanded uncertainty, from the nominal value of the weight,
iridium cylinder maintained at the International Bureau of
m :
o
Weights and Measures (BIPM), at Sevres, France with an
m 2 ~δm 2 U!# ~m !# m 1~δm 2 U! (1)
internationally accepted defined mass of 1 kg. o c o
3.1.8 reference standard—a standard, generally of the high-
4.2 Maximumpermissibleerrors(tolerances)onverification
est metrological quality available at a given location, from
for classes 0, 1, 2, 3, 4, 5, 6 and 7 are given in Table 1. These
which measurements made at that location are derived.
maximum permissible errors are related to conventional mass
3.1.9 set of weights—a series of weights, usually presented
values.
in a case so arranged to make possible any weighing of all
NOTE 1—Consistent with OIML R 111 the concept of group tolerances
loadsbetweenthemassoftheweightwiththesmallestnominal
has been dropped in the 1997 revision of this specification.
value and the sum of the masses of all weights of the series
NOTE 2—Tolerances for weights of denominations intermediate be-
with a progression in which the mass of the smallest nominal
tween those listed can be determined as follows. If the unit of measure is
value weight constitutes the smallest step of the series.
non-metric use the conversion factor from the Abbreviations of Terms
table in Appendix X3 to convert the nominal value to a metric unit. For
3.1.10 tolerance (adjustment tolerance or maximum permis-
weights that are intermediate between those listed, the tolerance for the
sible errors)—the maximum amount by which the conven-
next lower weight shall be applied.
tional mass of the weight is allowed to deviate from the
NOTE 3—Class 0 is a new designation with tolerances that are 50 % of
assigned nominal value.
Class 1, with physical characteristics the same as those of OIML R 111
Class E1.
3.1.11 tolerance test—verification that the conventional
NOTE 4—Class 7 is a new designation with the same tolerances as the
mass of the weights and their corresponding uncertainties as
former Class T in NBS Circular 3 (out of print).
testedarecorrectwithinthemaximumpermissibleerrorsofthe
respective weight class.
5. Physical Characteristics
3.1.12 traceability—property of the result of a measurement
5.1 Construction:
or the value of a standard whereby it can be related to stated
5.1.1 Type—Weights are divided into two types based upon
references, usually national or international standards, through
the design:
an unbroken chain of comparisons all having stated uncertain-
5.1.1.1 Type I—These weights are of one-piece construction
ties.
and contain no added adjusting material. They must be
3.1.12.1 Discussion—For more information see 3.1.14.
specified when weights are to be used as standards for the
calibration of weights of Classes 0, 1, 2 and 3, and where
maximum stability is required. A precise measurement of
Definition from International Vocabulary of Basic and General Terms in
density can only be made for one-piece weights.
Metrology.
5.1.1.2 Type II—Weights of this type can be of any appro-
Definition from NCSL Z-540-1-1994.
priate design such as screw knob, ring, or sealed plug.
Definition from OIML R33.
Definition from NIST/NVLAP Handbook 150. Adjusting material can be used as long as it is of a material at
E617−97 (2008)
TABLE 1 Maximum Tolerances
ASTM Tolerance Table ±mg except as noted
Denomination
Class 0 Class 1 Class 2 Class 3 Class 4 Class 5 Class 6 Class 7
5000 kg . . . . 100 g 250 g 500 g 750 g
3000 kg . . . . 60 g 150 g 300 g 450 g
2000 kg . . . . 40 g 100 g 200 g 300 g
1000 kg . . . . 20 g 50 g 100 g 150 g
500 kg . . . . 10 g 25 g 50 g 75 g
300 kg . . . . 6.0 g 15 g 30 g 45 g
200 kg . . . . 4.0 g 10 g 20 g 30 g
100 kg . . . . 2.0 g 5 g 10 g 15 g
50 kg 63 125 250 500 1.0 g 2.5 g 5 g 7.5 g
30 kg 38 75 150 300 600 mg 1.5 g 3 g 4.5 g
25 kg 31 62 125 250 500 1.2 g 2.5 g 4.5 g
20 kg 25 50 100 200 400 1.0 g 2 g 3.8 g
10 kg 13 25 50 100 200 500 mg 1 g 2.2 g
5 kg 6 12 25 50 100 250 500 mg 1.4 g
3 kg 3.8 7.5 15 30 60 150 300 1.0 g
2 kg 2.5 5.0 10 20 40 100 200 750 mg
1 kg 1.3 2.5 5.0 10 20 50 100 470
500 g 0.60 1.2 2.5 5.0 10 30 50 300
300 g 0.38 0.75 1.5 3.0 6.0 20 30 210
200 g 0.25 0.50 1.0 2.0 4.0 15 20 160
100 g 0.13 0.25 0.50 1.0 2.0 9 10 100
50 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 44
20 g 0.037 0.074 0.10 0.35 0.70 3.0 3 33
10 g 0.025 0.050 0.074 0.25 0.50 2.0 2 21
5 g 0.017 0.034 0.054 0.18 0.36 1.3 2 13
3 g 0.017 0.034 0.054 0.15 0.30 0.95 2.0 9.4
2 g 0.017 0.034 0.054 0.13 0.26 0.75 2.0 7.0
1 g 0.017 0.034 0.054 0.10 0.20 0.50 2.0 4.5
500 mg 0.005 0.010 0.025 0.080 0.16 0.38 1.0 3.0
300 mg 0.005 0.010 0.025 0.070 0.14 0.30 1.0 2.2
200 mg 0.005 0.010 0.025 0.060 0.12 0.26 1.0 1.8
100 mg 0.005 0.010 0.025 0.050 0.10 0.20 1.0 1.2
50 mg 0.005 0.010 0.014 0.042 0.085 0.16 0.50 0.88
30 mg 0.005 0.010 0.014 0.038 0.075 0.14 0.50 0.68
20 mg 0.005 0.010 0.014 0.035 0.070 0.12 0.50 0.56
10 mg 0.005 0.010 0.014 0.030 0.060 0.10 0.50 0.4
5 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 .
least as stable as the base material and is contained in such a 5.5 Magnetism—Weights shall not exceed maximum per-
way that it will not become separated from the weight. missiblemagneticpropertiesaslistedinTable2foranyportion
5.1.2 Class 0 must be Type I, one piece construction. of the weight:
5.1.3 Class 1, 2, 3, 4, 5, 6 and 7 can be eitherType I orType
NOTE 5—Cast iron cannot have a susceptibility specification of any real
II depending on the application.
value.
NOTE 6—The measurement method is incorporated from OIML
5.2 Design—A weight may have any shape that does not
R 111-2 (8th draft) in section A5.3.2, Susceptometer.
introduce features that reduce the reliability. All weights shall
5.6 Density—Because of the effect of the buoyant force of
be free of ragged or sharp edges or ends. Both sheet metal and
air on a weight, precision measurements of mass require that
wire weights shall be free of cracks such as may be formed
the volume of the weight be known, as well as the density of
from bending.
the air in which it is being measured, so that appropriate
5.3 Surface Area—For classes 0, 1, 2, 3 and 4 the surface
corrections can be made. For weights of higher precision, the
areaisnottoexceedtwicetheareaofacylinderofequalheight
anddiameterforweights1gandabove.Sheetmetalweightsor
wire weights may be used below 1 g.
TABLE 2 Magnetic Properties
Volume Magnetic Maximum Magnetic Field
5.4 Material:
Class
Susceptibility (χ)
µT mG
5.4.1 Class 0, 1, 2 and 3 Weights—The hardness of this
0 0.01 2.0 20
material and its resistance to wear and corrosion shall be
1 0.03 4.0 40
similar to or better than that of austenitic stainless steel.
2, 3, 4 0.05 6.0 60
AA A
5.4.2 Class 4, 5, 6 and 7—The hardness and brittleness of
5, 6, 7
the materials used for weights of Classes 4, 5, 6, and 7 shall be A
Requirements for these classes have not been developed.
at least equal to that of drawn brass.
E617−97 (2008)
TABLE 4 Maximum Values of Surface Roughness
range of density is limited to values at or near the density of
well-established standards, such as are used by primary cali- Classes 0 and 1 Classes 2, 3, 4 Class 5, 6, 7
R (µm) 0.025 0.05 0.8
A
bration laboratories. As lower precision of measurement is
R (µm) 0.35 0.67 3.2
Z
required, so the range of density is broadened. See
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:E617–97 (Reapproved 2003) Designation: E 617 – 97 (Reapproved 2008)
Standard Specification for
Laboratory Weights and Precision Mass Standards
This standard is issued under the fixed designation E 617; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This specification covers weights and mass standards used in laboratories, specifically classes 0, 1, 2, 3, 4, 5, 6 and 7. This
specification replaces National Bureau of Standards Circular 547, Section 1, which is out of print.
1.2 This specification further recognizes that International Recommendation R111 exists, that describes classes E1, E2, F1, F2,
M1, M2 and M3. Users may choose to reference either R111 or this specification, depending on requirements.
1.3 This specification contains the principal physical characteristics and metrological requirements for weights that are used.
1.3.1 For the verification of weighing instruments;
1.3.2 For the verification of weights of a lower class of accuracy; and
1.3.3 With weighing instruments.
1.4 Tolerances and design restrictions for each class are described in order that both individual weights or sets of weights can
be chosen for appropriate applications.
1.5 The values stated in SI units are to be regarded as the standard.
2. Referenced Documents
2.1ASTM Standards:
B46.1-1995Surface Texture (Surface Roughness, Waviness, and Lay) an American National Standard
2.1 ANSI Standard:
B 46.1-1995 Surface Texture (Surface Roughness, Waviness, and Lay) an American National Standard
2.2 ISO Standards:
International Vocabulary of Basic and General Terms in Metrology 1993, VIM, Geneve, Switzerland
Guide to the Expression of Uncertainty in Measurement
ISO/DIS 4287-1, Edition 01-Jun-95, Geometric Product Specification (GPS), Determination of Surface Texture by Profiling
Methods, Part 1: Terms, Definitions and Parameters
2.3 NCSL Standards:
NCSL Glossary of Metrology—Related Terms
NCSL Recommended Practice-12 Determining and Reporting Measurement Uncertainties
ANSI/NCSL-Z540-1-1994 American National Standard for Calibration-Calibration Laboratories and Measuring and Test
Equipment General Requirements
2.4 NIST Standards:
NISTNVLAPDraftHandbook150-2 NationalVoluntaryLaboratoryAccreditationProgramCalibrationLaboratoriesTechnical
Guide
NIST NVLAP Handbook 150 National Voluntary Laboratory Accreditation Program (NVLAP), NIST Handbook 150,
Procedures and General Requirements
NIST Technical Note 1297 (1994) Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results
2.5 OIML Standard:
This specification is under the jurisdiction of ASTM Committee E41 on Laboratory Apparatus, and is the direct responsibility of Subcommittee E41.06 on Weighing
Devices.
Current edition approved Nov. 10, 1997. Published March 1998. Originally published as E617–78. Last previous edition E617–91.
Current edition approved Dec. 1, 2008. Published February 2009. Originally approved in 1978. Last previous edition approved in 2003 as E 617 – 97 (2003).
Available from ASME Service Center, 22 Law Drive, PO Box 2900, Fairfield, New Jersey 07007-2900.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Available from American National Standards Institute, 11 West 42nd Street, New York, New York 10036.
Available from NCSL, National Conference of Standards Laboratories, 1800 30th Street, Suite 305B, Boulder, Colorado 80301.
Available from NCSL, National Conference of Standards Laboratories, 1800 30th Street, Suite 305B, Boulder, Colorado 80301.
Available from NIST/NVLAP, National Voluntary LaboratoryAccreditation Program, 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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E 617 – 97 (2008)
OIML Recommendation 33 Conventional Value of the Result of Weighing in Air
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 accuracy class of weights—a class of weights that meets certain metrological requirements intended to keep the errors
within specified limits.
3.1.2 calibration—the acts of determining the mass difference between a standard of known mass value and an “unknown” test
weight or set of weights, establishing the mass value and conventional mass value of the “unknown”, and of determining a
quantitative estimate of the uncertainty to be assigned to the stated mass or conventional mass value of the “unknown”, or both.
Set of operations that establish, under specified conditions, the relationship between values of quantities indicated by a measuring
instrument or measuring system, or values represented by a material measure or a reference material, and the corresponding values
realized by standards.
3.1.3 certificate of tolerance test—document that certifies that the subject weights are within specified tolerances.
3.1.3.1 Discussion—If traceability is claimed, some level of uncertainty must be addressed.
3.1.4 certificate or report of calibration—document that presents calibration results and other information relevant to a
calibration.
3.1.5 conventional mass—conventional value of the result of weighing in air, in accordance to International Recommendation
OIMLR 33.Foraweighttakenat20°C,theconventionalmassisthemassofareferenceweightofadensityof8000kg/m which
3 9
it balances in air of density of 1.2 kg/m .
3.1.5.1 Discussion—Formerly known as apparent mass versus 8.0 g/cm .
3.1.6 correction—mass values are traditionally expressed by two numbers, one being the nominal mass of the weight, and the
second being a correction. The mass of the weight is the assigned nominal value plus the assigned correction. Positive corrections
indicate that the weight embodies more mass than is indicated by the assigned nominal value.
3.1.7 international prototype kilogram—the platinum-iridium cylinder maintained at the International Bureau of Weights and
Measures (BIPM), at Sevres, France with an internationally accepted defined mass of 1 kg.
3.1.8 reference standard—a standard, generally of the highest metrological quality available at a given location, from which
measurements made at that location are derived.
3.1.9 set of weights—a series of weights, usually presented in a case so arranged to make possible any weighing of all loads
between the mass of the weight with the smallest nominal value and the sum of the masses of all weights of the series with a
progression in which the mass of the smallest nominal value weight constitutes the smallest step of the series.
3.1.10 tolerance (adjustment tolerance or maximum permissible errors)—the maximum amount by which the conventional
mass of the weight is allowed to deviate from the assigned nominal value.
3.1.11 tolerance test—verification that the conventional mass of the weights and their corresponding uncertainties as tested are
correct within the maximum permissible errors of the respective weight class.
3.1.12 traceability—property of the result of a measurement or the value of a standard whereby it can be related to stated
references, usually national or international standards, through an unbroken chain of comparisons all having stated uncertainties.
3.1.12.1 Discussion—For more information see 3.1.14.
3.1.13 uncertainty—parameter associated with the result of a measurement, that characterizes the dispersion of the values that
could reasonably be attributed to the measurand. The range of values within which the true value is estimated to lie.
3.1.14 U.S. National prototype standard—platinumiridium kilogram identified as K20, maintained at the National Institute of
Standards and Technology, with value assigned relative to the International Prototype Kilogram provides the United States access
to the mass unit.
3.1.15 weight (mass standard)—a material measure of mass, regulated in regard to its physical and metrological characteristics:
shape, dimension, material, surface quality, nominal value, and maximum permissible error.
3.1.15.1 Discussion—Not to be confused with a gravitational 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 conventional mass
Available from NIST/NVLAP, National Voluntary LaboratoryAccreditation Program, 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.
Available from Organisation Internationale de Metrologie Legale, 11 Rue Turgot, 75009 Paris, France.
Available from Organisation Internationale de Metrologie Legale, 11 Rue Turgot, 75009 Paris, France.
Definition from OIML R111.
Definition from OIML R111.
Definition from International Vocabulary of Basic and General Terms in Metrology.
Definition from International Vocabulary of Basic and General Terms in Metrology.
Definition from NCSL Z-540-1-1994.
Definition from NCSL Z-540-1-1994.
Definition from OIML R33.
Definition from OIML R33.
Definition from NIST/NVLAP Handbook 150.
E 617 – 97 (2008)
shall be less than or equal to one-third of the maximum permissible error given in Table 1.
4.1.1 For each weight, the conventional mass, m (determined with an expanded uncertainty), shall not differ by more than the
c
difference: maximum permissible error dm minus expanded uncertainty, from the nominal value of the weight, m :
o
m 2 ~dm 2 U!# ~m !# m 1 ~dm 2 U! (1)
o c o
4.2 Maximum permissible errors (tolerances) on verification for classes 0, 1, 2, 3, 4, 5, 6 and 7 are given in Table 1. These
maximum permissible errors are related to conventional mass values.
NOTE 1—Consistent with OIML R 111 the concept of group tolerances has been dropped in the 1997 revision of this specification.
NOTE 2—Tolerances for weights of denominations intermediate between those listed can be determined as follows. If the unit of measure is non-metric
use the conversion factor from the Abbreviations of Terms table in Appendix X3 to convert the nominal value to a metric unit. For weights that are
intermediate between those listed, the tolerance for the next lower weight shall be applied.
NOTE 3—Class 0 is a new designation with tolerances that are 50 % of Class 1, with physical characteristics the same as those of OIML R 111 Class
E1.
NOTE 4—Class 7 is a new designation with the same tolerances as the former Class T in NBS Circular 3 (out of print).
5. Physical Characteristics
5.1 Construction:
5.1.1 Type—Weights are divided into two types based upon the design:
5.1.1.1 Type I—These weights are of one-piece construction and contain no added adjusting material. They must be specified
when weights are to be used as standards for the calibration of weights of Classes 0, 1, 2 and 3, and where maximum stability is
required. A precise measurement of density can only be made for one-piece weights.
5.1.1.2 Type II—Weights of this type can be of any appropriate design such as screw knob, ring, or sealed plug. Adjusting
TABLE 1 Maximum Tolerances
ASTM Tolerance Table 6mg except as noted
Denomination
Class 0 Class 1 Class 2 Class 3 Class 4 Class 5 Class 6 Class 7
5000 kg . . . . 100 g 250 g 500 g 750 g
3000 kg . . . . 60 g 150 g 300 g 450 g
2000 kg . . . . 40 g 100 g 200 g 300 g
1000 kg . . . . 20 g 50 g 100 g 150 g
500 kg . . . . 10 g 25 g 50 g 75 g
300 kg . . . . 6.0 g 15 g 30 g 45 g
200 kg . . . . 4.0 g 10 g 20 g 30 g
100 kg . . . . 2.0 g 5 g 10 g 15 g
50 kg 63 125 250 500 1.0 g 2.5 g 5 g 7.5 g
30 kg 38 75 150 300 600 mg 1.5 g 3 g 4.5 g
25 kg 31 62 125 250 500 1.2 g 2.5 g 4.5 g
20 kg 25 50 100 200 400 1.0 g 2 g 3.8 g
10 kg 13 25 50 100 200 500 mg 1 g 2.2 g
5 kg 6 12 25 50 100 250 500 mg 1.4 g
3 kg 3.8 7.5 15 30 60 150 300 1.0 g
2 kg 2.5 5.0 10 20 40 100 200 750 mg
1 kg 1.3 2.5 5.0 10 20 50 100 470
500 g 0.60 1.2 2.5 5.0 10 30 50 300
300 g 0.38 0.75 1.5 3.0 6.0 20 30 210
200 g 0.25 0.50 1.0 2.0 4.0 15 20 160
100 g 0.13 0.25 0.50 1.0 2.0 9 10 100
50 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 44
20 g 0.037 0.074 0.10 0.35 0.70 3.0 3 33
10 g 0.025 0.050 0.074 0.25 0.50 2.0 2 21
5 g 0.017 0.034 0.054 0.18 0.36 1.3 2 13
3 g 0.017 0.034 0.054 0.15 0.30 0.95 2.0 9.4
2 g 0.017 0.034 0.054 0.13 0.26 0.75 2.0 7.0
1 g 0.017 0.034 0.054 0.10 0.20 0.50 2.0 4.5
500 mg 0.005 0.010 0.025 0.080 0.16 0.38 1.0 3.0
300 mg 0.005 0.010 0.025 0.070 0.14 0.30 1.0 2.2
200 mg 0.005 0.010 0.025 0.060 0.12 0.26 1.0 1.8
100 mg 0.005 0.010 0.025 0.050 0.10 0.20 1.0 1.2
50 mg 0.005 0.010 0.014 0.042 0.085 0.16 0.50 0.88
30 mg 0.005 0.010 0.014 0.038 0.075 0.14 0.50 0.68
20 mg 0.005 0.010 0.014 0.035 0.070 0.12 0.50 0.56
10 mg 0.005 0.010 0.014 0.030 0.060 0.10 0.50 0.4
5 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 .
E 617 – 97 (2008)
material can be used as long as it is of a material at least as stable as the base material and is contained in such a way 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 Type II depending on the application.
5.2 Design—Aweight may have any shape that does not introduce features that reduce the reliability.All weights shall be free
of ragged or sharp edges or ends. Both sheet metal and wire weights shall be free of cracks such as may be formed from bending.
5.3 Surface Area—For classes 0, 1, 2, 3 and 4 the surface area is not to exceed twice the area of a cylinder of equal height and
diameter for weights 1 g and above. Sheet metal weights or wire weights may be used below 1 g.
5.4 Material:
5.4.1 Class 0, 1, 2 and 3 Weights—The hardness of this material and its resistance to wear and corrosion shall be similar to or
better
...
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