Powered by Google www.ChineseStandard.net Database: 189760 (20 Jul 2024)

GB/T 6499-2012 PDF in English


GB/T 6499-2012 (GB/T6499-2012, GBT 6499-2012, GBT6499-2012)
Standard IDContents [version]USDSTEP2[PDF] delivered inName of Chinese StandardStatus
GB/T 6499-2012English155 Add to Cart 0-9 seconds. Auto-delivery. Test method for percentage of trash content in raw cotton Obsolete
GB/T 6499-2022English189 Add to Cart 3 days Test method for percentage of trash content in raw cotton Valid
Newer version: GB/T 6499-2022
PDF Preview

Standards related to: GB/T 6499-2012

GB/T 6499-2012: PDF in English (GBT 6499-2012)

GB/T 6499-2012
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 59.060.10
B 32
Replacing GB/T 6499-2007
Test method for percentage of trash content in raw cotton
ISSUED ON: NOVEMBER 14, 2012
IMPLEMENTED ON: SEPTEMBER 01, 2013
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions ... 4
4 Principle ... 5
5 Instruments and apparatuses ... 5
6 Instrument adjustment ... 5
7 Sampling ... 5
8 Test procedures ... 5
9 Calculation of test results ... 6
10 Precision ... 7
11 Test report ... 8
Appendix A (Normative) Specifications of Y101-type raw cotton trash analyzer ... 9
Appendix B (Normative) Specifications of YG042-type raw cotton trash analyzer ... 10
Test method for percentage of trash content in raw cotton
1 Scope
This Standard specifies the test method for determining the percentage of trash content
in raw cotton using a raw cotton trash analyzer.
This Standard applies to the determination for percentage of trash content in raw cotton.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies to this document. For
undated references, the latest edition (including any amendment) applies to this
document.
GB 1103.1, Cotton - Part 1: Saw ginned upland cotton
GB 1103.2, Cotton - Part 2: Roller ginned upland cotton
GB 1103.3, Cotton - Natural color uplands cotton
GB/T 6097, Sampling method for testing of cotton fibers
GB/T 8170, Rules of rounding off for numerical values & expression and judgment
of limiting values
GB 19635, Cotton - Sea island cotton
3 Terms and definitions
The following terms and definitions are applicable to this document.
3.1 Trash
Non-cotton fibrous substances and the inserted fibers, contained in raw cotton, such as
sand, branches and leaves, boll shells, insect excrement, insect carcasses, cotton seeds,
seed cotton, broken seeds, sterile seeds, fibrous seed chips, soft seed epidermis.
3.2 Percentage of trash
The percentage of trash mass to sample mass in the specified sample of raw cotton.
4 Principle
The raw cotton trash analyzer is designed according to the principle of mechanical
aerodynamics. For the loose fibers and adhering trashes combed by the licker-in and
saw, under the action of machinery and air flow, the fibers and trashes are separated due
to different shapes, different specific gravity and different forces acting on them.
5 Instruments and apparatuses
5.1 Raw cotton trash analyzer: technical parameters in accordance with Appendix A and
Appendix B.
5.2 Balance: accuracy level II, measuring range ≥100 g, graduation value 0.01 g.
5.3 Bench scale or counter scale: accuracy level III, measuring range 200 g, graduation
value 1 g.
5.4 Other tools: coir scrub brush, tweezers.
6 Instrument adjustment
Adjust the instrument to the normal state according to the instrument instruction manual.
7 Sampling
7.1 Implement the sampling method and quantity in accordance with the provisions of
GB 1103.1, GB 1103.2, GB 1103.3, GB 19635 and GB/T 6097.
7.2 From the 600 g of laboratory sample, use the quartering method to take two parts
of 100 g test samples and one part of 100 g standby test sample.
8 Test procedures
8.1 Before starting the machine, turn on the lights and open all the fan valves. Start
idling for 1 min ~ 2 min; then, stop to clean the trash box, clean cotton box, cotton
feeding table and licker-in.
8.2 Use an electronic scale or a counter scale to weigh the laboratory sample, to the
nearest 1 g. Use a balance to weigh the test sample, to the nearest 0.1 g; record the mass.
8.3 Tear the test samples loose, and spread them evenly on the cotton feeding table one
after another. Where there are cottonseed, seed cotton and other coarse trashes, pick
10 Precision
10.1 Repeatability
10.1.1 For two individual tests – completed using the test method of this Standard, on
the same laboratory sample, under the same conditions (same laboratory, same operator,
same equipment and within a short time interval) – the absolute value of the difference
between the results of the percentage of trash, at the 95% probability level, shall be less
than the repeatability value r1. The low trash content r1 value less than 2.5% is equal to
0.18%; the high trash content r1 value greater than or equal to 2.5% is equal to 0.29%.
Note that an individual test refers to a complete test carried out on the same laboratory
sample using the standard test method.
10.1.2 For the tests of two test samples – completed using the test method of this
Standard, on the same laboratory sample, under the same conditions (same laboratory,
same operator, same equipment and within a short time interval) – the absolute value
of the difference between the results of the percentage of trash, at the 95% probability
level, shall be less than the repeatability value r2. The low trash content r2 value less
than 2.5% is equal to 0.24%; the high trash content r2 value greater than or equal to 2.5%
is equal to 0.39%.
10.1.3 For three test samples tested under the conditions of repeated values – in the
same laboratory, on the same laboratory sample – if the range of the test results is greater
than 0.29% (low trash content) or 0.47% (high trash content), one more test shall be
performed. Use the Grubbs method for anomalous value checking of the test results of
the test sample; take the arithmetic mean of all the results after removing the anomalous
value as the final test result.
10.2 Reproducibility
10.2.1 For an individual test – respectively completed using the test method of this
Standard, on the same laboratory sample, under the different conditions (different
laboratories, different operators and different equipment) – the absolute value of the
difference between the results of the percentage of trash, at the 95% probability level,
shall be less than the reproducibility value R1. The low trash content R1 value less than
2.5% is equal to 0.44%.
10.2.2 For the test of individual test samples – respectively completed using the test
method of this Standard, on the same laboratory sample, under different conditions
(different laboratories, different operators and different equipment) – the absolute value
of the difference between the results of the percentage of trash, at the 95% probability
level, shall be less than the reproducibility value R2. The low trash content R2 value less
than 2.5% is equal to 0.47%.
......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.