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适用范围：<p>This test method is intended for use in the laboratory or in the field for evaluating the cleanliness of distillate fuels, and liquid bio fuels. It is not applicable to on or in-line applications.</p> <p>This test method offers advantage over traditional filtration methods in that it is a precise rapid test, and advantage over visual methods as it is not subjective.</p> <p>An increase in particle counts can indicate a change in the fuel condition caused by storage or transfer for example.</p> <p>High levels of particles can cause filter blockages and have a serious impact on the life of pumps, injectors, pistons and other moving parts. Knowledge of particle size in relation to the metallurgy can provide vital information especially if the hardness of particles is also known from other sources.</p> <p>This test method specifies a minimum requirement for reporting measurements in particle size bands (see A1.1.2). Some specific applications may require measurements in other particle size bands.</p> <p>Obtaining a representative sample and following the recommended sample and test specimen preparation procedures and timescales is particularly important with particle counting methods. (See Sections 8, 10, 14.1.4 and Note 8.)</p><p id="s00002">1.1 This test method uses a specific automatic particle counter (APC) to count and measure the size of dispersed dirt particles, water droplets and other particles, in light and middle distillate fuel, and bio fuels such as biodiesel and biodiesel blends, in the overall range from 4 <span class="unicode">x00B5;</span>m(c) to 100 <span class="unicode">x00B5;</span>m(c) and in the size bands <span class="unicode">x2265;</span>4 <span class="unicode">x00B5;</span>m(c), <span class="unicode">x2265;</span>6 <span class="unicode">x00B5;</span>m(c), and <span class="unicode">x2265;</span>14 <span class="unicode">x00B5;</span>m(c).</p> <p class="desc" id="N00001"> <span class="smallcap">Note</span> 18212;ASTM specification fuels falling within the scope of this test method include Specifications: <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D975-HTML">D975</a> grades 1D and 2D, <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D3699-HTML">D3699</a>, <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D4814-HTML">D4814</a> (see 14.1.1.1), <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D6751-HTML">D6751</a>, <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D6985-HTML">D6985</a>, <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D7467-HTML">D7467</a> and distillate grades of <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D396-HTML">D396</a> and <a href="http://myastm.astm.org/SUBSCRIPTION/NewValidateSubscription.cgi?D2880-HTML">D2880</a>.</p> <p class="desc" id="N00002"> <span class="smallcap">Note</span> 28212;For the purposes of this test method, water droplets are counted as particles, and agglomerated particles are detected and counted as a single larger particle. Dirt includes biological particles. Although the projected area of a particle is measured, this is expressed as the diameter of a sphere for the purposes of this test method.</p> <p class="desc" id="N00003"> <span class="smallcap">Note</span> 38212;The notation (c), used with particle sizes, is used to denote that the apparatus has been calibrated in accordance with ISO 11171. Strictly this only applies to particles up to 50 <span class="unicode">x00B5;</span>m.</p> <p class="desc" id="N00004"> <span class="smallcap">Note</span> 48212;This test method may be used for particle sizes bands up to 100 <span class="unicode">x00B5;</span>m(c), however the precision has only been determined for the size bands <span class="unicode">x2265;</span>4 <span class="unicode">x00B5;</span>m(c), <span class="unicode">x2265;</span>6 <span class="unicode">x00B5;</span>m(c), and ......