ASTM D4860 Standard Test Method for Free Water and Particulate Contamination in Mid-Distillate Fuels (Clear and Bright Numerical Rating)
11. Procedure
11.1 Visual inspection for water or particulate contamination.
11.1.1 Immediately upon drawing a sample for field testing, check visually for evidence of water or particulate contamination. Hold the sample container up to the ambient light source and view the fuel through the walls of the container, visually examining for haze or lack of clarity. Check the same sample by swirling the fuel in the sample container to produce a vortex. The bottom of the vortex is visually examined 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. Cap the container.
11.2 Numerical Rating of Free Water Using Micro-Separometer Mark V Deluxe:
11.2.1 Select the clear-and-bright test mode by depressing the push button marked C which illuminates. The syringe drive mechanism travels to the UP position and the proper syringe drive speed is automatically selected.
11.2.2 Prepare Fuel Sample:
11.2.2.1 Remove a plunger from a new 50-mL syringe, insert a plug into the tapered bottom of the syringe, and add 50 +/- 1 mL of fuel sample into the barrel of syringe.
11.2.2.2 Insert the plunger using the wire aid to release the entrapped air. Insert the wire aid in the syringe barrel with the loop end out. (To ensure that only the entrapped air is expelled without fuel loss, the syringe barrel should be cocked at a slight angle with the wire aid held against the upper portion of the barrel - Fig. 3.) Insert the plunger to the 50-mL mark on the syringe barrel. Remove the wire aid from the syringe. Remove the plug from the syringe and replace it with an Alumicel coalescer.
11.2.3 Prepare for Coalescing/Filter Process:
11.2.3.1 Place the entire syringe assembly into the syringe drive mechanism. Electrically bond the coalescer/filter to the instrument by using the ground lead provided. Insert the end with the banana plug into the recepticle located left of the syringe drive mechanism and attach the alligator clip to one of the coalescer/filter fins. Position a waste container beneath the Alumicel coalescer/filter to collect the unwanted portion of the processed fuel sample during the coalescing/filtering period of the test (Fig. 4).
NOTE 5 - Caution: Alumicel coalescer/filters should be electrically bonded to the Micro-Separometer to prevent buildup of an electrostatic charge that could result in ignition of flammable test fluids (Fig. 4).
11.2.4 Initiate the Coalescing/Filtering Process:
11.2.4.1 Depress the START push button which initiates the automatic program (see Table 1). The automatic program is a series of timed events controlled by the instrument that begins with the syringe drive mechanism forcing the fuel through the Alumicel coalescer/filter.
11.2.4.2 Disregard the first 5 mL of expended fuel and, using a new vial, collect the next 15 mL of fuel sample being processed from the Alumicel coalescer/filter (Fig. 5). To lessen the amount of air introduced into the fuel during this operation, position the vial at a slight angle and allow the fuel to flow down the inner surface.
11.2.4.3 Wipe the outside of the vial with a clean, lintless wiper to remove fingerprints and fuel. Place the sample vial into the turbidimeter well aligning the marks on the vial with those on the control panel in front of the well.
11.2.5 Adjust the meter to the 100 reference level.
11.2.5.1 A short 4-s tone sounds followed by the meter activating for 10 s. During this period, the meter is adjusted to the 100 reference level by depressing the appropriate ARROWED push buttons. At the end of the 10-s period, the meter will deactivate for 30 s. Once the meter deactivates, further adjustment of the meter from this point on through the end of the test is not possible.
11.2.6 Perform Measurement:
11.2.6.1 Remove the vial from the turbidimeter well and discard the sample. Half fill the vial with fresh fuel sample that has not been processed (filtered).
11.2.6.2 Wipe the outside of the vial with a clean, lintless wiper to remove fingerprints and fuel. Place the sample vial into the turbidimeter well aligning the marks on the vial with those on the control panel in front of the well.
11.2.7 Read the MSEP-C&B Rating:
11.2.7.1 Following the 30-s METER OFF period that occurs after the coalescing/filtering process, a 4-s tone sounds and the METER automatically activates for a period of 10 s. During this period, read and record the value displayed on the meter.
