ASTM D7619 - Sizing and Counting Particles in Light and Middle Distillate Fuels, by Automatic Particle Counter
Signiﬁcance and Use
5.1 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.
5.2 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.
5.3 An increase in particle counts can indicate a change in the fuel condition caused by storage or transfer for example.
5.4 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.
5.5 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.
5.6 Obtaining a representative sample and following the recommended sample and test specimen preparation proce-dures and timescales is particularly important with particle counting methods. (See Sections 8, 10, 14.1.4 and Note 8.)
5.7 This test method can also be used to estimate the total particulate counts excluding free water droplets in aviation turbine fuels by a chemical pretreatment of the fuel.
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 µm(c) to 100 µm(c) and in the size bands ≥4 µm(c), ≥6 µm(c), and ≥14 µm(c).
NOTE 1—ASTM and military speciﬁcation fuels falling within the scope of this test method include Speciﬁcations: D975 grades 1D and 2D, D1655, D3699, D4814 (see 188.8.131.52), D6751, D7467, distillate grades of D396 and D2880, MIL-DTL-83133, and MIL-DTL-16884.
NOTE 2—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.
NOTE 3—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 µm.
NOTE 4—This test method may be used for particle sizes bands up to 100 µm(c), however the precision has only been determined for the size bands ≥4 µm(c), ≥6 µm(c), and ≥14 µm(c). All measurements are per millilitre.
Extracted, with permission, from ASTM D7619-17- Sizing and Counting Particles in Light and Middle Distillate Fuels, by Automatic Particle Counter, copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. A copy of the complete standard may be purchased from ASTM International, astm.org