ASTM D2258-99(2012)
(Practice)Standard Practice for Sampling Yarn for Testing
Standard Practice for Sampling Yarn for Testing
SIGNIFICANCE AND USE
Assigning a value to any property of the material in a container or in a lot, consignment, or delivery involves a measurement process that includes both sampling and testing procedures. The correctness of the value assigned depends upon the variability due to testing. Even when the variability due to testing is minimized by carefully developed procedures, correct and consistent estimates of the true value of the property are possible only when the sampling procedure avoids systematic bias, minimizes variations due to sampling, and provides a laboratory sample of adequate size.
Practice D2258 may not give the most efficient sampling plan that might be devised in special situations but does present a general procedure that gives satisfactory precision with an economical amount of sampling and one which does not require elaborate statistical computation based on previous knowledge of the amount of variation between primary sampling units (such as cases, beams or fabric packages), between units of the laboratory sample taken from the primary sampling units of the lot sample (such as yarn packages taken from a case) and between specimens taken from units of the laboratory sample (such as lengths of yarn taken from a yarn package or a fabric swatch taken from a roll or piece). Many plans that include stratified sampling can be found in textbooks.
The smallest number of specimens required for a given variability in the average result will usually be obtained by (1) maximizing the number of shipping containers in the lot sample, (2) taking a single package end per shipping container in the laboratory sample, and (3) taking only one specimen per package. Unfortunately, this is rarely the most economical way to test a product because it normally costs most to take a shipping container as part of the lot sample, costs an intermediate amount to take a package from a shipping container as part of a laboratory sample, and costs least to take and test a specimen from a package...
SCOPE
1.1 This practice describes a procedure for the division of shipments of yarn into test lots and the sampling of such lots for testing.
1.2 This practice is applicable to single, plied, or cabled yarns, and cords, made of any fiber or mixture of fibers, and supported on any form of package, including beams.
1.3 This practice also describes procedures for the sampling of yarn(s) removed from woven or knitted fabrics, however, when thus sampled, the yarns are usually not representative of entire shipments, as referred to in 1.1. Consequently, the resultant sampling can only be used to determine the characteristics of the yarn and is usually not used for acceptance testing. Moreover, it should be recognized that the characteristics of yarns from fabrics may be different than the characteristics of the same yarn(s), prior to being entered into the fabric manufacturing process.
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as the standard. Within the text, the inch-pound units are shown in parentheses. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with this practice.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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
Designation: D2258 − 99(Reapproved 2012)
Standard Practice for
Sampling Yarn for Testing
This standard is issued under the fixed designation D2258; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope D1578 Test Method for Breaking Strength of Yarn in Skein
Form
1.1 This practice describes a procedure for the division of
D1907 Test Method for Linear Density of Yarn (Yarn Num-
shipments of yarn into test lots and the sampling of such lots
ber) by the Skein Method
for testing.
D4271 Practice for Writing Statements on Sampling in Test
1.2 This practice is applicable to single, plied, or cabled
Methods for Textiles (Withdrawn 2009)
yarns, and cords, made of any fiber or mixture of fibers, and
D4849 Terminology Related to Yarns and Fibers
supported on any form of package, including beams.
3. Terminology
1.3 This practice also describes procedures for the sampling
of yarn(s) removed from woven or knitted fabrics, however,
3.1 For terminology related to Yarns and Fibers, see Termi-
when thus sampled, the yarns are usually not representative of
nology D4849.
entire shipments, as referred to in 1.1. Consequently, the
3.2 The following terms are relevant to this standard: beam,
resultant sampling can only be used to determine the charac-
beam set, bulk sample, case, cone, end, fabric package,
teristics of the yarn and is usually not used for acceptance
laboratory sample, lot, lot sample, primary sampling unit,
testing. Moreover, it should be recognized that the character-
production lot, sample, sampling unit, sample skein, specimen,
istics of yarns from fabrics may be different than the charac-
and yarn package.
teristics of the same yarn(s), prior to being entered into the
3.3 FordefinitionsofallothertextiletermsseeTerminology
fabric manufacturing process.
D123.
1.4 The values stated in either SI units or inch-pound units
are to be regarded separately as the standard. Within the text,
4. Summary of Practice
the inch-pound units are shown in parentheses. The values
4.1 Instructions are given for dividing the yarn into lots, for
stated in each system are not exact equivalents; therefore, each
determining the number of cases, beams, or fabric packages to
system shall be used independently of the other. Combining
be selected from each lot as a lot sample, and for determining
values from the two systems may result in nonconformance
the number of packages, including the number of ends,
with this practice.
representing those packages taken from the lot sample as a
1.5 This standard does not purport to address all of the
laboratory sample. See Practice D4271.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Significance and Use
priate safety and health practices and determine the applica-
5.1 Assigning a value to any property of the material in a
bility of regulatory limitations prior to use.
container or in a lot, consignment, or delivery involves a
2. Referenced Documents
measurement process that includes both sampling and testing
procedures. The correctness of the value assigned depends
2.1 ASTM Standards:
upon the variability due to testing. Even when the variability
D123 Terminology Relating to Textiles
due to testing is minimized by carefully developed procedures,
correct and consistent estimates of the true value of the
ThispracticeisunderthejurisdictionofASTMCommitteeD13onTextilesand
propertyarepossibleonlywhenthesamplingprocedureavoids
is the direct responsibility of Subcommittee D13.58 on Yarns and Fibers.
Current edition approved March 1, 2012. Published April 2012. Originally
systematic bias, minimizes variations due to sampling, and
approved in 1964. Last previous edition approved in 2005 as D2258 – 99(2005).
provides a laboratory sample of adequate size.
DOI: 10.1520/D2258-99R12.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2258 − 99 (2012)
NOTE 1—An adequate specification or other agreement between the
5.2 PracticeD2258maynotgivethemostefficientsampling
purchaser and the supplier requires taking into account the variability
planthatmightbedevisedinspecialsituationsbutdoespresent
between shipping units, between packages or ends within a shipping unit,
a general procedure that gives satisfactory precision with an
and between specimens from a single package so as to provide a sampling
economical amount of sampling and one which does not
plan with a meaningful producer’s risk, consumer’s risk, acceptable
require elaborate statistical computation based on previous
quality level, and limiting quality level.
knowledge of the amount of variation between primary sam-
6.2.1 Cases or Fabric Packages—For the lot sample, assign
pling units (such as cases, beams or fabric packages), between
each case or fabric package with consecutive numbers and take
unitsofthelaboratorysampletakenfromtheprimarysampling
for acceptance testing, the number of cases or fabric packages
units of the lot sample (such as yarn packages taken from a
specified in Table 1. Select the cases or fabric packages by a
case)andbetweenspecimenstakenfromunitsofthelaboratory
random process using the assigned numbers by either placing
sample (such as lengths of yarn taken from a yarn package or
these numbers on small slips or chips, placing them in a
a fabric swatch taken from a roll or piece). Many plans that
container, mixing thoroughly and drawing out the number or
include stratified sampling can be found in textbooks.
numbers by selection, or by using a random number table or its
computer equivalent.
5.3 The smallest number of specimens required for a given
6.2.1.1 When fabric packages, such as bolts or pieces, are
variability in the average result will usually be obtained by (1)
contained in cases, consider the case as the sampling unit.
maximizing the number of shipping containers in the lot
When fabric packages, such as rolls are self-contained, con-
sample, (2 ) taking a single package end per shipping container
sider the individual fabric package as the sampling unit.
in the laboratory sample, and (3) taking only one specimen per
6.2.1.2 When known, fabric packages, such as rolls, pieces,
package. Unfortunately, this is rarely the most economical way
or bolts produced from one beam set may be treated in the
to test a product because it normally costs most to take a
same manner as beams.
shipping container as part of the lot sample, costs an interme-
6.2.2 Beams—For the lot sample, assign each beam with
diate amount to take a package from a shipping container as
consecutivenumbersandtakeforacceptancetesting,onebeam
part of a laboratory sample, and costs least to take and test a
from the beam set. Select the beam by a random process using
specimen from a package or yarn.
the assigned numbers by either placing these numbers on small
5.4 To minimize the cost of sampling a lot of material, it is
slips or chips, placing them in a container, mixing thoroughly
necessary to agree on the required variance for the reported
and drawing out the number by selection, or by using a random
average for a lot of material:
number table or its computer equivalent.
5.4.1 Estimate the variance due to lot samples, the variance
6.3 Laboratory Sample—For a laboratory sample for accep-
due to laboratory samples, and the variance due to testing
tance testing, unless otherwise agreed upon, as when specified
specimens.
in an applicable material specification, proceed as follows:
5.4.2 Calculate the total variance for average test results for
6.3.1 Cases—When sampling cases, take a total of ten
several combinations of the number of lot samples, the number
packages from the lot sample. When there are five cases in the
of laboratory samples per lot sample, and the number of
lot sample, select randomly two packages from each case.
specimens per laboratory sample.
When there are four cases in the lot sample, select randomly
5.4.3 Calculate the cost of performing each of the sampling
two packages from each case then randomly select two of the
schemes considered in 5.4.2.
fourcasesandselectrandomlyathirdpackagefromeachofthe
5.4.4 Select the sampling scheme that (1) has the required
selected cases. When there are three cases in the lot sample,
precision and (2) is most economical to perform.
select randomly three packages from each case then randomly
select one of the three cases and select randomly a fourth
6. Procedure
package from the selected case. When there are two cases in
6.1 Division into Lots—Instructions on the division of
the lot sample, select randomly five packages from each case.
product into lots is best given in the appropriate specification.
When there is one case in the lot sample, select randomly ten
In the absence of such instructions, sample and test as a
packages from the case.
separate lot any portion of a shipment or order that differs from
other portions in specifications, put-up, or physical
characteristics, or that is billed or designated by the supplier as
A,B
TABLE 1 Number of Cases, Beams, or Fabric Packages
a separate lot. If portions of a larger order are shipped on
In Lot In Lot Sample
different dates, from plants or warehouses, or in more than one
carload or truckload, treat each such separately shipped portion
2to4 2
as a separate lot. If the cases in a shipment do not have
5to9 3
consecutive numbers, divide the shipment into groups of cases
10 to 19 4
20 or more 5
having consecutive numbers and treat each group as a separate
A
For cases containing only a few packages per case, enough cases must be taken
lot if it is separated from an adjacent group by as many as ten
in the lot sample so there will be at least ten packages in the lot sample. (See
case numbers. Treat each beam set as a sep
...
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