GB/T 6679-2003 English PDF (GBT6679-2003)

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GB/T 6679-2003: General rules for sampling solid chemical products
GB/T 6679-2003
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.100.01
G 04
Replacing GB/T 6679-1986
General rules for sampling solid chemical products
ISSUED ON: OCTOBER 11, 2003
IMPLEMENTED ON: MAY 01, 2004
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People’s Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 General ... 4
4 Sampling techniques ... 6
5 Sample preparation ... 9
6 Sampling report ... 11
Appendix A (Informative) Sampling probe ... 12
Appendix B (Informative) Sampling drill ... 15
Appendix C (Informative) Pneumatic and vacuum probes ... 16
Appendix D (Informative) Sample divider ... 19
Appendix E (Informative) Automatic sampler ... 23
General rules for sampling solid chemical products
1 Scope
This standard specifies the sampling techniques, sample preparation, and sampling
report for solid chemical products.
This standard applies to the sampling of solid chemical products. This standard does
not apply to the sampling of suspended solids and slurries in gases.
2 Normative references
The terms in the following documents become the terms of this standard by reference.
For dated references, all subsequent amendments (not including errata content) or
revisions do not apply to this standard. However, parties reaching an agreement based
on this standard are encouraged to study whether the latest versions of these documents
can be used. For undated references, the latest version applies to this standard.
GB/T 3723, Sampling of chemical products for industrial use - Safety in sampling
(GB/T 3723-1999, idt ISO 3165:1976)
GB/T 6678-2003, General principles for sampling chemical products
3 General
3.1 Sample types of solid chemical products
Sample types include partial sample, directional sample, representative sample, cross-
sectional sample and geometric sample.
The sample type shall be determined based on the sampling purpose, sampling
conditions, and material conditions (batch size, geometric state, particle size, uniformity,
and variability distribution of characteristic values).
3.2 Basic requirements for samples
3.2.1 Sampling inspection is an inspection method that evaluates and judges the quality
of the overall material by inspecting samples. The sample must be representative of the
overall material characteristics.
3.2.2 The amount of samples collected shall be able to represent all the characteristics
of the overall material and meet the optimal amount required for inspection (according
to GB/T 6678).
3.2.3 The number of samples collected: The number of samples collected shall be
determined according to the packaging form of the overall materials and the unevenness
of the materials, and in accordance with Sub-clause 7.6 and Clause 11 of GB/T 6678-
2003. In view of the particularity of solid chemical products, it is recommended to use
the following method to determine the number of samples to collect.
3.2.3.1 Unit materials: According to the provisions of Sub-clause 7.6.1 and Clause 11
of GB/T 6678-2003.
3.2.3.2 Bulk materials
a) If the batch size is less than 2.5 t, take 7 units (or points);
b) If the batch size is 2.5 t ~ 80 t, take:
ඥ𝐵𝑎𝑡𝑐ℎ ሺ𝑡ሻ ൈ 20 units (or points), calculated to an integer;
c) If the batch size is greater than 80 t, take 40 units (or points).
3.3 Sampling steps
3.3.1 Determine the sampling purpose (according to GB/T 6678).
3.3.2 Determine the sampling objects.
3.3.3 Develop a sampling plan.
3.3.4 Take samples using appropriate equipment and techniques.
3.3.5 Prepare samples.
3.4 Sampling plan
3.4.1 A sampling plan must be developed before sampling.
3.4.2 The purpose of developing a sampling plan is to obtain representative samples of
the overall material at the lowest cost and within the allowable sampling error range.
3.4.3 The factors that must be considered when developing a sampling plan are mainly
the sampling purpose, the difference in overall material characteristic values, the
allowable sampling error, and the packaging and transportation method of the material
(according to the provisions of GB/T 6678).
3.4.4 The theoretical basis for formulating the sampling plan is specified in GB/T 6678.
3.4.5 Basic contents of sampling plan.
The basic contents of the sampling plan are specified in Sub-clause 6.2 of GB/T 6678-
2003.
3.5 Others
3.5.1 Since there are many types of solid chemical products and the sampling conditions
are ever-changing, the sampling shall be based on the basic principles and methods
specified in this standard, and the optimal sampling plan and sampling techniques shall
be selected according to the actual situation and possibility.
3.5.2 Before sampling, the materials to be sampled shall be pre-inspected. According to
the contract established by both parties, check the material name, batch number,
quantity, net content, color, appearance damage, and use all feasible methods and means
to understand as much detail as possible the nature of materials, the difference in
material characteristic values and the packaging conditions. Feasibility experiments
shall be conducted on the selected sampling methods and devices to understand
deviations.
4 Sampling techniques
4.1 Principle for selecting sampling techniques
4.1.1 The principles for selecting sampling techniques shall be based on the shape,
particle size, quantity, difference in material characteristic values, and state (stationary
or moving) of the materials to be sampled.
4.1.2 The sampling technique shall be able to ensure that a representative sample of the
overall material is obtained within the allowable sampling error range.
4.1.3 The sampling technique must not have any impact on the properties of the material
to be measured.
4.1.4 The sampling technique shall be complete, convenient and low-cost.
4.1.5 For solids that require special processing and for hazardous solids, select
appropriate special sampling techniques according to relevant regulations.
4.2 Basic requirements for samplers and sample dividers
4.2.1 The materials used must not have any reaction with the materials to be sampled,
and must not cause contamination, delamination or loss of the materials to be sampled.
4.2.2 It shall be clean, dry, easy to use, clean, maintain, inspect and repair.
4.2.3 Any sampling device (especially automatic sampler) shall be subject to a
feasibility test before formal use.
If the material can be crushed with appropriate equipment, take samples
according to the method in 4.3.1 after crushing.
4.3.3 Sampling of massive materials
4.3.3.1 Stationary materials
Respectively take partial samples, directional samples, geometric samples or
representative samples according to the material conditions. They are separately
described as follows:
a) Partial sample
Use an appropriate tool to take a certain amount of material from the required
part. If the material is hard, use a drill or saw to process the material at the required
part. Collect all drill or sawdust as a sample. When processing heat-sensitive
materials, an appropriate inert coolant shall be used to cool the tool.
b) Directional sample
For single or continuous massive material, break the massive material into two
pieces in the required direction. Cut the newly exposed surface and collect all
cuttings as a sample.
If the material is hard, use a dr...