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适用范围：<p>It is intended that this practice be used to provide a sample representative of the coal from which it is collected. Because of the variability of coal and the wide variety of mechanical sampling equipment available, caution should be used in all stages of the sample collection process, the design of sampling system specifications, the equipment procurement and the acceptance testing of installed equipment.</p> <p>After removal from the sampling system and further preparation (Practice <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D2013-HTML">D2013</a>), the sample may be analyzed for a number of different parameters. These parameters may define the lot''s value, its ability to meet specifications, its environmental impact, as well as other properties.</p><p id="s00002">1.1 This practice is divided into 4 parts. These 4 parts represent the previous standards <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D7256/D7256M-HTML">D7256/D7256M</a>, <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D4916-HTML">D4916</a>, <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D4702-HTML">D4702</a>, and <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D6518-HTML">D6518</a>. These 4 standards are the 4 that govern the mechanical sampling of coal and have been combined into one document for the ease of reference of the users of these standards.</p> <h3 id="colhd2">Part A</h3> <div class="top"> Top </div> <p id="s00003">1.2 <span class="italic"><span class="italic">Part A<char: emdash>Mechanical Collection and Within-System Preparation of a Gross Sample of Coal from Moving Streams</span>8212;</span>Covers procedures for the mechanical collection of a sample under Classification I-B-1 and I-B-2 (Practice <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D2234/D2234M-HTML">D2234/D2234M</a>) and the within-system preparation (reduction and division) of gross samples utilizing various components of the mechanical sampling system.</p> <p id="s00004">1.2.1 Part A describes mechanical sampling procedures for coals <span class="italic">(1)</span> by size and condition of preparation (for example, mechanically cleaned coal or raw coal), and <span class="italic">(2)</span> by sampling characteristics.</p> <p>1.2.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.</p> <h3 id="colhd3">Part B</h3> <div class="top"> Top </div> <p id="s00005">1.3 <span class="italic"><span class="italic">Part B<char: emdash>Mechanical Auger Sampling<char: emdash></span>8212;</span>Describes procedures for the collection of an increment, partial sample, or gross sample of material using mechanical augers. Reduction and division of the material by mechanical equipment at the auger is also covered. Further manual or mechanical reduction or division of the material elsewhere shall be performed in accordance with Practice <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D2013-HTML">D2013</a>.</p> <p>1.3.1 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.</p> <h3 id="colhd4">Part C</h3> <div class="top"> Top </div> <p id="s00006">1.4 <span class="italic"><span class="italic">Part C<char: emdash>Quality Management of Mechanical Coal Sampling Systems</span>8212;</span>Is applicable to the quality management of cross-belt, falling stream, and auger sampling systems.</p> <p id="s00007">1.4.1 Spacing of increments pertains to the kind of interval between increments. Intervals can be defined in quantitative terms, such as units of time or mass, or in terms of position o......