ASTM D4176 method for free water and particulate contamination in distillate fuel
ASTM D4176 standard test method for free water and particulate contamination in distillate fuels (visual inspection procedures)
10. Procedure
10.1 Procedure 1 - Check visually for evidence of water or particulate contamination. Hold the sample up to the light and visually examine for haze or lack of clarity. Swirl the sample to produce a vortex and examine the bottom of the vortex for particulate matter. Record the visual clarity as clear and bright or not clear and bright. Record if particulate matter or water was or was not viewed at the bottom of the vortex.
10.2 Procedure 2 - Place the sample container into a well lighted area, avoiding light reflections on the front of the container as much as possible. Place the bar chart directly behind the container, with the lines toward the container and parallel with the container bottom. The narrowest line should be at the bottom of the chart.
10.2.1 Directly facing the container and bar chart, compare the appearance of the bar chart through the sample with the standard photographs. Place the photographs next to the container so that they are lighted similarly to the sample. Select the photograph closest in appearance to the sample. Ignore differences in fuel color. Notice that the differences between photographs consist both of the successive disappearance of lines as well as a gradual lightening of all the lines. Record the number of the photograph closest in appearance as the rating of the sample.
10.2.2 Remove the bar chart and swirl the sample container to produce a vortex. Examine the bottom of the vortex for particulate matter and water droplets. Record the presence of any particulates or water.
10.2.3 Also record any special observation, such as a particularly heavy contamination with water or solids or a darker than usual color which made ratings difficult.
