ASTM E617-97
(Specification)Standard Specification for Laboratory Weights And Precision Mass Standards
Standard Specification for Laboratory Weights And Precision Mass Standards
SCOPE
1.1 This specification covers various classes of weights and mass standards used in laboratories. Weights used for commercial measurements are excluded, except that one class of standards designed for the calibration of commercial test weights is included. 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 (see Note). In general, this specification replaces, in function, National Bureau of Standards Circular 547, Section 1, which is out of print. Note-Although metric weights are almost exclusively used in laboratories, tolerances are given in this specification for nonmetric weights in U.S. customary units for all classes. It is anticipated that as metrication, even in test laboratories, proceeds further, the nonmetric tables given in this specification will become obsolete.
1.2 This specification recognizes International Recommendation No. 1 (cylindrical weights from 1 g to 10 kg of average precision) and International Recommendation No. 20 (weights of classes of precision E1, E2, F1, F2, and M1 from 50 kg to 1 mg). Where appropriate, it is recommended that these International Recommendations be used.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 617 – 97
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
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 (e) 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
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
NIST Technical Note 1297 (1994) Guidelines for Evaluat-
accuracy; and
ing and Expressing the Uncertainty of NIST Measurement
1.3.3 With weighing instruments.
Results
1.4 Tolerances and design restrictions for each class are
2.5 OIML Standard:
described in order that both individual weights or sets of
OIML Recommendation 33 Conventional Value of the Re-
weights can be chosen for appropriate applications.
sult of Weighing in Air
1.5 The values stated in SI units are to be regarded as the
standard.
3. Terminology
2. Referenced Documents 3.1 Definitions of Terms Specific to This Standard:
3.1.1 accuracy class of weights—a class of weights that
2.1 ASTM Standards:
meets certain metrological requirements intended to keep the
B 46.1-1995 Surface Texture (Surface Roughness, Wavi-
errors within specified limits.
ness, and Lay) an American National Standard
3.1.2 calibration—the acts of determining the mass differ-
2.2 ISO Standards:
ence between a standard of known mass value and an “un-
International Vocabulary of Basic and General Terms in
known” test weight or set of weights, establishing the mass
Metrology 1993, VIM, Geneve, Switzerland
3 value and conventional mass value of the “unknown”, and of
Guide to the Expression of Uncertainty in Measurement
determining a quantitative estimate of the uncertainty to be
ISO/DIS 4287-1, Edition 01-Jun-95, Geometric Product
assigned to the stated mass or conventional mass value of the
Specification (GPS), Determination of Surface Texture by
“unknown”, or both. Set of operations that establish, under
Profiling Methods, Part 1: Terms, Definitions and Param-
eters
1 4
This specification is under the jurisdiction of ASTM Committee E-41 on Available from NCSL, National Conference of Standards Laboratories, 1800
Laboratory Apparatus, and is the direct responsibility of Subcommittee E41.06 on 30th Street, Suite 305B, Boulder, Colorado 80301.
Weighing Devices. Available from NIST/NVLAP, National Voluntary Laboratory Accreditation
Current edition approved Nov. 10, 1997. Published March 1998. Originally Program, NIST, Gaithersburg, Maryland 20899. HB 150 available on-line: http://
published as E 617 – 78. Last previous edition E 617 – 91. ts.nist.gov/nvlap and Technical Note 1297 available on-line: http://physics.nist.gov/
Available from ASME Service Center, 22 Law Drive, PO Box 2900, Fairfield, Pubs/guidelines/outline.html.
New Jersey 07007-2900. Available from Organisation Internationale de Metrologie Legale, 11 Rue
Available from American National Standards Institute, 11 West 42nd Street, Turgot, 75009 Paris, France.
New York, New York 10036. Definition from OIML R111.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E 617
specified conditions, the relationship between values of quan- that could reasonably be attributed to the measurand. The
tities indicated by a measuring instrument or measuring sys- range of values within which the true value is estimated to lie.
tem, or values represented by a material measure or a reference 3.1.14 U.S. National prototype standard—platinumiridium
material, and the corresponding values realized by standards. kilogram identified as K20, maintained at the National Institute
3.1.3 certificate of tolerance test—document that certifies of Standards and Technology, with value assigned relative to
that the subject weights are within specified tolerances. the International Prototype Kilogram provides the United
3.1.3.1 Discussion—If traceability is claimed, some level of States access to the mass unit.
uncertainty must be addressed. 3.1.15 weight (mass standard)—a material measure of
3.1.4 certificate or report of calibration—document that mass, regulated in regard to its physical and metrological
presents calibration results and other information relevant to a characteristics: shape, dimension, material, surface quality,
9 7
calibration. nominal value, and maximum permissible error.
3.1.5 conventional mass—conventional value of the result 3.1.15.1 Discussion—Not to be confused with a gravita-
of weighing in air, in accordance to International Recommen- tional force.
dation OIML R 33. For a weight taken at 20°C, the conven-
4. Maximum Permissible Errors (Tolerances)
tional mass is the mass of a reference weight of a density of
3 3
8000 kg/m which it balances in air of density of 1.2 kg/m .
4.1 For each weight, the expanded uncertainty U at 95 %
3.1.5.1 Discussion—Formerly known as apparent mass ver-
confidence (See Annex B of OIML R 111) of the conventional
sus 8.0 g/cm .
mass shall be less than or equal to one-third of the maximum
3.1.6 correction—mass values are traditionally expressed
permissible error given in Table 1.
by two numbers, one being the nominal mass of the weight,
4.1.1 For each weight, the conventional mass, m (deter-
c
and the second being a correction. The mass of the weight is
mined with an expanded uncertainty), shall not differ by more
the assigned nominal value plus the assigned correction.
than the difference: maximum permissible error dm minus
Positive corrections indicate that the weight embodies more
expanded uncertainty, from the nominal value of the weight,
mass than is indicated by the assigned nominal value.
m :
o
3.1.7 international prototype kilogram—the platinum-
m 2 ~dm 2 U! # ~m ! # m 1 ~dm 2 U! (1)
o c o
iridium cylinder maintained at the International Bureau of
4.2 Maximum permissible errors (tolerances) on verification
Weights and Measures (BIPM), at Sevres, France with an
for classes 0, 1, 2, 3, 4, 5, 6 and 7 are given in Table 1. These
internationally accepted defined mass of 1 kg.
maximum permissible errors are related to conventional mass
3.1.8 reference standard—a standard, generally of the high-
values.
est metrological quality available at a given location, from
which measurements made at that location are derived.
NOTE 1—Consistent with OIML R 111 the concept of group tolerances
3.1.9 set of weights—a series of weights, usually presented
has been dropped in the 1997 revision of this specification.
NOTE 2—Tolerances for weights of denominations intermediate be-
in a case so arranged to make possible any weighing of all
tween those listed can be determined as follows. If the unit of measure is
loads between the mass of the weight with the smallest nominal
non-metric use the conversion factor from the Abbreviations of Terms
value and the sum of the masses of all weights of the series
table in Appendix X3 to convert the nominal value to a metric unit. For
with a progression in which the mass of the smallest nominal
weights that are intermediate between those listed, the tolerance for the
value weight constitutes the smallest step of the series.
next lower weight shall be applied.
3.1.10 tolerance (adjustment tolerance or maximum permis-
NOTE 3—Class 0 is a new designation with tolerances that are 50 % of
sible errors)—the maximum amount by which the conven-
Class 1, with physical characteristics the same as those of OIML R 111
tional mass of the weight is allowed to deviate from the Class E1.
assigned nominal value. NOTE 4—Class 7 is a new designation with the same tolerances as the
former Class T in NBS Circular 3 (out of print).
3.1.11 tolerance test—verification that the conventional
mass of the weights and their corresponding uncertainties as
5. Physical Characteristics
tested are correct within the maximum permissible errors of the
5.1 Construction:
respective weight class.
5.1.1 Type—Weights are divided into two types based upon
3.1.12 traceability—property of the result of a measurement
the design:
or the value of a standard whereby it can be related to stated
5.1.1.1 Type I—These weights are of one-piece construction
references, usually national or international standards, through
and contain no added adjusting material. They must be
an unbroken chain of comparisons all having stated uncertain-
specified when weights are to be used as standards for the
ties.
calibration of weights of Classes 0, 1, 2 and 3, and where
3.1.12.1 Discussion—For more information see 3.1.14.
maximum stability is required. A precise measurement of
3.1.13 uncertainty—parameter associated with the result of
density can only be made for one-piece weights.
a measurement, that characterizes the dispersion of the values
5.1.1.2 Type II—Weights of this type can be of any appro-
priate design such as screw knob, ring, or sealed plug.
Definition from International Vocabulary of Basic and General Terms in
Adjusting material can be used as long as it is of a material at
Metrology.
least as stable as the base material and is contained in such a
Definition from NCSL Z-540-1-1994.
way that it will not become separated from the weight.
Definition from OIML R33.
Definition from NIST/NVLAP Handbook 150. 5.1.2 Class 0 must be Type I, one piece construction.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E 617
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 .
5.1.3 Class 1, 2, 3, 4, 5, 6 and 7 can be either Type I or Type TABLE 2 Magnetic Properties
II depending on the application.
Volume Magnetic Maximum Magnetic Field
Class
Susceptibility (x)
5.2 Design—A weight may have any shape that does not
μT mG
introduce features that reduce the reliability. All weights shall
0 0.01 2.0 20
be free of ragged or sharp edges or ends. Both sheet metal and
1 0.03 4.0 40
2, 3, 4 0.05 6.0 60
wire weights shall be free of cracks such as may be formed
AA A
5, 6, 7
from bending.
A
Requirements for these classes have not been developed.
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
NOTE 6—The measurement method is incorporated from OIML
and diameter for weights 1 g and above. Sheet metal weights or
R 111-2 (8th draft) in section A5.3.2, Susceptometer.
wire weights may be used below 1 g.
5.4 Material:
5.6 Density—Because of the effect of the buoyant force of
5.4.1 Class 0, 1, 2 and 3 Weights—The hardness of this
air on a weight, precision measurements of mass require that
material and its resistance to wear and corrosion shall be
the volume of the weight be known, as well as the density of
similar to or better than that of austenitic stainless steel.
the air in which it is being measured, so that appropriate
5.4.2 Class 4, 5, 6 and 7—The hardness and brittleness of
corrections can be made. For weights of higher precision, the
the materials used for weights of Classes 4, 5, 6, and 7 shall be
range of density is limited to values at or near the density of
at least equal to that of drawn brass.
well-established standards, such as are used by primary cali-
5.5 Magnetism—Weights shall not exceed maximum per-
bration labor
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.