ASTM E29-02e1

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
e1
Designation: E 29 – 02
Standard Practice for
Using Significant Digits in Test Data to Determine
1
Conformance with Specifications
ThisstandardisissuedunderthefixeddesignationE 29;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1
e NOTE—Editorial changes were made to Footnote 4, Table 1, and Paragraph 7.4 in November 2003.
1. Scope digits. Zeros trailing the last nonzero digit for numbers
represented with a decimal point are significant digits. For
1.1 This practice is intended to assist the various technical
example, the numbers 1270. and 32.00 each have four signifi-
committees in the use of uniform methods of indicating the
cant digits. The significance of trailing zeros for numbers
number of digits which are to be considered significant in
represented without use of a decimal point can only be
specification limits, for example, specified maximum values
identified from knowledge of the source of the value. For
and specified minimum values. Its aim is to outline methods
example, a modulus strength, stated as 140 000 Pa, may have
which should aid in clarifying the intended meaning of
as few as two or as many as six significant digits.
specification limits with which observed values or calculated
3.1.2 To eliminate ambiguity, the exponential notation may
test results are compared in determining conformance with
5
be used. Thus, 1.40 3 10 indicates that the modulus is
specifications.
5
reported to the nearest 0.01 3 10 or 1000 Pa.
1.2 This practice is intended to be used in determining
3.1.3 Use of appropriate SI prefixes is recommended for
conformance with specifications when the applicable ASTM
metric units to reduce the need for trailing zeros of uncertain
specifications or standards make direct reference to this prac-
significance. Thus, 140 kPa and 0.140 MPa each indicate that
tice.
the modulus is reported to the nearest 1 kPa or 1000 Pa, while
1.3 Reference to this practice is valid only when a choice of
140 kPa may again have two or three significant digits.
method has been indicated, that is, either absolute method or
rounding method.
4. Significance and Use
2. Referenced Documents 4.1 This practice describes two commonly accepted meth-
odsofroundingdata,identifiedastheAbsoluteMethodandthe
2.1 ASTM Standards:
2
Rounding Method. In the applications of this practice to a
E 456 Terminology Relating to Quality and Statistics
specific material or materials it is essential to specify which
SI 10 Standard for Use of the International System of Units
3
method is intended to apply. In the absence of such specifica-
(SI) (the Modernized Metric System)
tion, reference to this practice, which expresses no preference
3. Terminology
as to which method should apply, would be meaningless. The
choice of method is arbitrary depending upon the current
3.1 significant digit, n—any of the figures 0 through 9,
practice of the particular branch of industry or technology
excepting leading zeros and some trailing zeros, which is used
concerned, and should therefore be specified in the prime
with its place value to denote a numerical quantity to some
publication.
desired approximation.
4.1.1 Theunqualifiedstatementofanumericallimit,suchas
3.1.1 The digit zero may either indicate a specific value or
“2.50 in. max,” cannot, in view of different established
indicate place only. Zeros leading the first nonzero digit of a
practices and customs, be regarded as carrying a definite
number indicate order of magnitude only and are not signifi-
operational meaning concerning the number of digits to be
cantdigits.Forexample,thenumber0.0034hastwosignificant
retained in an observed or a calculated value for purposes of
determining conformance with specifications.
1
This practice is under the jurisdiction ofASTM Committee E11 on Quality and
4.1.2 Absolute Method—In some fields, specification limits
Statistics and is the direct responsibility of Subcommittee E11.30 on DataAnalysis.
of 2.5 in. max, 2.50 in. max, and 2.500 in. max are all taken to
Current edition approved May 10, 2002. Published July 2002. Originally
imply the same absolute limit of exactly two and a half inches
published as E 29 – 40. Last previous edition E 29 – 93 (1999).
2
Annual Book of ASTM Standards, Vol 14.02.
3
Annual Book of ASTM Standards, Vol 14.04.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
e1
E29–02
and for purposes of determining conformance with specifica-
...