5.1 This test method is intended for use in the laboratory or in the field for evaluating the cleanliness of fuels identified in the scope.

5.2 Detection of particles and water can indicate degradation of the fuel condition. Particles, whether inorganic or organic, can cause fouling of fuel filters and damage pumps, injectors, and pistons. Knowledge of particle size in relation to metallurgy can provide vital information, especially if the hardness of the solid particles are known from other sources.

Note 3: The method includes the detection of water, solids, and air bubbles. The air bubbles are screened out of the data prior to analysis of results, based on shape and transparency, and are not reported in the results.

1.1 This test method uses a direct imaging particle analyzer (DIPA) to count and measure the size and shape of dispersed solid particles and water droplets in light and middle distillate fuels in the overall range from 4 μm to 100 μm and in size bands of ≥4 μm, ≥6 μm, and ≥14 μm.

Note 1: Particle size data from 0.7 μm through 300 μm is available for use or reporting if deemed helpful.

Note 2: Shape is used to classify particles, droplets, and bubbles and is not a reporting requirement.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 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.