FREE WATER IN DISTILLATE FUELS: D4176
TEST SUMMARY
Fuel specifications often contain the requirement that it be clear and bright and free of visible particulate matter. This test method provides two procedures to cover that requirement. This test method is applicable to distillate fuels having distillation end points below 400° C and an ASTM color of 5 or less. Both procedures are performed immediately after sampling and at storage temperature conditions.
PROCEDURE A - is a rapid pass/fail method for contamination. Approximately 900 mL of fuel is placed into a 1 L jar of clear glass, and is examined visually for clarity. The sample is then swirled and examined for visual sediment or water drops below the vortex.
PROCEDURE B - provides a gross numerical rating of haze appearance. Approximately 900 mL of fuel is placed into a 1 L jar of clear glass and is examined visually for clarity. Fuel clarity is rated by comparing against a standard bar chart and haze rating photos. The sample is then swirled and examined for visual sediment or water drops below the vortex.
TEST PRECISION
Procedure A is a pass/fail test and precision statement is not appropriate.
Procedure B has a repeatability of 1 number and a reproducibility of 2 numbers rating.
No bias statement is possible for this test.