ASTM D3025-07(2012)
(Practice)Standard Practice for Standardizing Cotton Fiber Test Results by Use of Calibration Cotton Standards
Standard Practice for Standardizing Cotton Fiber Test Results by Use of Calibration Cotton Standards
SIGNIFICANCE AND USE
The purpose of this practice is to provide guiding principles for the use of reference standard cottons for the standardization of instruments and techniques to obtain reproducible test results (within statistical limits) when the tests are performed on samples of cotton fibers by the same or different operators at the same or different times, both within the same laboratory and in different laboratories.
Results obtained on cotton fiber tests on the same sample may vary widely due to differences in instruments and operator techniques. Some variation in test result levels can be controlled by the physical adjustment of instruments in accordance with manufacturers' instruction. Instrument adjustments are made only to cause instrument values to coincide with specified calibration points established by the manufacturer. Other variations in cotton fiber test results are caused by differences in technique used in specimen preparation, errors in reading test values from scales, variation in the reference standard, and sampling errors in specimen selection. It is necessary that the mean value of at least four sets of determinations per operator-instrument be used in order to form a sound basis for any adjustment of technique or for the use of correction factors.
In comparing results of different operators and different laboratories, for example, between the purchaser and the seller, it is essential that all results be obtained on replicate specimens. Values obtained on individual samples, as well as on a reference standard are never absolute, but have a normal variation about their mean due to heterogeneity of the sample. Therefore confidence limits of a test value are dependent upon the within laboratory variance for the test and the sampling error. The level of the results in different laboratories will be comparable only to the extent of the use of the same reference standards in both laboratories.
Any one set of determinations on a reference standard may be with...
SCOPE
1.1 This practice covers the use of reference standard cottons for the standardization of instruments and techniques used to test cotton fibers in various laboratories.
1.2 Standardization may be achieved by application of a correction factor based on the reference standards, or by modification of the technique in use.
Note 1—When reference standards are used to develop correction factors, or to adjust an operator's technique, no instrument calibration processes are involved. The term “Calibration” is properly used for the application or assignment of permanent scales or marks to an instrument. Adjustments can be made to specific instruments and accessories such as orifices, metallic strips, or cellophane sheets, in order to obtain the prescribed values with a specific instrument. Since an operator's technique or the interpretation of a method or procedure is inherently variable, it cannot be calibrated, that is, assigned a permanent, definite value. The use of reference standards, however, affords a means for standardizing techniques and checking the reliability of observed results.
1.3 This practice recognizes two types of reference standards: (1) calibration cotton standards (see 6.1) and (2) working cotton standards (see 6.2).
1.4 The instructions included in this practice can be used with cotton fibers in any form suitable for testing with the particular instrument to be used.
1.5 The instructions in the practice are applicable to cotton fibers but can also be applied to specific blends of cotton and other fibers, or to other fibers that can be tested with the instruments designed for testing cotton fibers. No information is available, however, to show that test procedures standardized with reference cotton samples are equally reliable with various cotton fiber blends or with other fibers.
Note 2—Standardization procedures covered in this practice are recommended for use with the following: Test Meth...
General Information
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: D3025 − 07 (Reapproved 2012)
Standard Practice for
Standardizing Cotton Fiber Test Results by Use of
Calibration Cotton Standards
This standard is issued under the fixed designation D3025; 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 responsibility of the user of this standard to consult and
establish appropriate safety and health practices and deter-
1.1 This practice covers the use of reference standard
mine the applicability of regulatory limitations prior to use.
cottons for the standardization of instruments and techniques
used to test cotton fibers in various laboratories.
2. Referenced Documents
1.2 Standardization may be achieved by application of a
2.1 ASTM Standards:
correction factor based on the reference standards, or by
D123 Terminology Relating to Textiles
modification of the technique in use.
D1440 Test Method for Length and Length Distribution of
Cotton Fibers (Array Method)
NOTE 1—When reference standards are used to develop correction
D1445 TestMethodforBreakingStrengthandElongationof
factors, or to adjust an operator’s technique, no instrument calibration
processes are involved. The term “Calibration” is properly used for the
Cotton Fibers (Flat Bundle Method)
application or assignment of permanent scales or marks to an instrument.
D1447 Test Method for Length and Length Uniformity of
Adjustments can be made to specific instruments and accessories such as
Cotton Fibers by Photoelectric Measurement
orifices, metallic strips, or cellophane sheets, in order to obtain the
D1448 Test Method for Micronaire Reading of Cotton Fi-
prescribedvalueswithaspecificinstrument.Sinceanoperator’stechnique
bers
or the interpretation of a method or procedure is inherently variable, it
cannot be calibrated, that is, assigned a permanent, definite value.The use
D7139 Terminology for Cotton Fibers
of reference standards, however, affords a means for standardizing
techniques and checking the reliability of observed results. 3. Terminology
1.3 This practice recognizes two types of reference stan- 3.1 For all terminology relating to D13.11, Cotton Fibers,
dards: (1) calibration cotton standards (see 6.1) and (2)
refer to Terminology D7139.
working cotton standards (see 6.2). 3.1.1 The following terms are relevant to this standard:
calibration cotton standard, reference standard, working cotton
1.4 The instructions included in this practice can be used
standard.
with cotton fibers in any form suitable for testing with the
particular instrument to be used.
3.2 For all other terminology related to textiles, refer to
Terminology D123.
1.5 The instructions in the practice are applicable to cotton
fibers but can also be applied to specific blends of cotton and
4. Summary of Practice
other fibers, or to other fibers that can be tested with the
4.1 Testing instruments are adjusted in accordance with
instruments designed for testing cotton fibers. No information
engineering principles to ensure that they correspond properly
isavailable,however,toshowthattestproceduresstandardized
to the manufacturer’s calibration scales and instructions for the
with reference cotton samples are equally reliable with various
operation of the instrument.
cotton fiber blends or with other fibers.
4.2 Technicians are instructed to operate testings instru-
NOTE 2—Standardization procedures covered in this practice are
ments in a consistent manner utilizing appropriate prescribed
recommended for use with the following: Test Methods D1440, D1445,
ASTM methods.
D1447, and D1448.
1.6 This standard does not purport to address all of the 4.3 Specimens of the working cotton standard or calibration
cotton standard are tested before and periodically during the
safety concerns, if any, associated with its use. It is the
routine testing of cotton samples using the same techniques for
all specimens tested.
ThispracticeisunderthejurisdictionofASTMCommitteeD13onTextilesand
is the direct responsibility of Subcommittee D13.11 on Cotton Fibers. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 1, 2012. Published August 2012. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1972. Last previous edition approved in 2007 as D3025–07. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D3025-07R12. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D3025 − 07 (2012)
4.4 Observed values for samples tested are adjusted through adjustments and test an additional set of test specimens from
use of a correction factor calculated from observed values thereferencestandardcotton.Themeanvalueofthesetwosets
obtained on reference standards to secure comparative level of of determinations, where instrument checks have shown the
measurement. adjustments (instruments) to be in order, may then be used as
a basis for modification of technique, or if correction factors
5. Significance and Use
are to be used, the basis for the initiation of testing of unknown
samples. Correction factors should be based on determinations
5.1 The purpose of this practice is to provide guiding
made before, during, and at the completion of routine testing.
principles for the use of reference standard cottons for the
standardization of instruments and techniques to obtain repro-
6. Reference Samples
ducible test results (within statistical limits) when the tests are
6.1 Calibration Cotton Standards:
performed on samples of cotton fibers by the same or different
6.1.1 Calibration cotton standards are furnished with a
operators at the same or different times, both within the same
statement of the mean values for one or more physical
laboratory and in different laboratories.
characteristics, along with the precision of the quoted mean
5.2 Results obtained on cotton fiber tests on the same
value. Such standards should be used only for those physical
sample may vary widely due to differences in instruments and
characteristics for which mean values have been furnished.
operator techniques. Some variation in test result levels can be
6.2 Working Cotton Standards:
controlled by the physical adjustment of instruments in accor-
6.2.1 Using working cotton standards conserves the supply
dance with manufacturers’ instruction. Instrument adjustments
ofthemoreexpensivecalibrationcottonstandards.Wellbefore
are made only to cause instrument values to coincide with
the supply of a working cotton standard has been depleted, a
specified calibration points established by the manufacturer.
new working cotton standard should be prepared. It is good
Other variations in cotton fiber test results are caused by
laboratory practice to run the old and new working cotton
differencesintechniqueusedinspecimenpreparation,errorsin
standards in parallel for a period of time sufficient to ensure
reading test values from scales, variation in the reference
that no changes in test result levels will occur at the time of
standard, and sampling errors in specimen sel
...
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