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适用范围：<p>A properly collected sample that includes the total coal bed interval provides a sample that is a representative cross section of the coal bed at the point of sampling. Core samples are taken for subsequent testing needed for evaluation of coal quality and characterization for commercial evaluations, for planning of mining operations to maintain coal quality, for the determination of coal rank in accordance with Classification D 388<astmref rid="a00002">, and for geologic coal resource studies. </p> <p class="desc" id="N00001"> <span class="smallcap">Note</span> 18212;Because of the potential for lateral variability, a sample may not represent the quality of the coal bed at another sample point. The reliability of the data generated from core samples is dependent on the number and spacing of the sample points and the variability of the coal characteristics in a given area. </p> <p>Moisture determined directly from a core sample shall be considered <span class="italic">questionable</span> in any core sample because of possible contamination from drilling fluids and groundwater. If a more representative estimate of the inherent moisture content of the core sample (with the exception of certain low-rank coals) is desired, the sample should be analyzed according to Test Method D 1412<astmref rid="a00003">. </p><p id="s00002">1.1 This practice describes procedures for collecting and handling a coal sample from a core recovered from a borehole. </p> <p id="s00003">1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.</p> <p id="s00004">1.3 <span class="italic">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. </span>