ASTM D2276 for Particulate Contaminant in Aviation Fuel by Line Sampling
8. Preparation of Test and Control Membrane Filters and Field Monitors Prior to Sampling
8.1 Two 37-mm membrane filters of nominal pore size 0.8 µm are required: a test and a control membrane filter. Matched-weight membrane filters may be used if so desired (see Note 1). If matched-weight membrane filters are used, it is unnecessary to carry out the procedures detailed in this section because they have been carried out previously by the membrane filter supplier. The two membrane filters used for each individual test should be identified by marking the petri dishes used as containers. Glassware used in preparation of membrane filters shall be cleaned as described in Section 10.
8.1.1 Using forceps, place the test and control membrane filters side by side in a clean petri dish. To facilitate handling the membrane filters should rest on clean glass support rods in the petri dish.
8.1.2 Place the petri dish with its lid slightly ajar, in an oven at 90 ± 5°C and leave it for 30 min.
8.1.3 Remove the petri dish from the oven and place it near the balance. The petri dish cover should be ajar but still protecting the membrane filters from contamination from the atmosphere. Allow 30 min for the membrane filters to come to equilibrium with the ambient air temperature and humidity.
8.1.4 Remove the control membrane filter from the petri dish with forceps, handling by the edge only, and place it centrally on the weighing pan. Weigh it and return it to the petri dish.
8.1.5 Repeat 8.1.4 for the test membrane filter. Record the membrane filter masses.
8.1.6 Take a clean field monitor, mark for identification, rinse with filtered flushing fluid, and insert a clean support pad.
8.1.7 Using clean forceps, place the weighed control membrane filter centrally on the support pad in the field monitor and place the weighed test membrane filter on top of the control membrane filter. Assemble the two parts of the field monitor, ensuring that the membrane filters are firmly clamped inside and the protective plugs are in position.
8.1.8 Record the monitor identification.
9. Sampling
9.1 When possible, 3.785 L (1 gal) to 5 L of fuel (Warning - Jet A, combustible. Vapor harmful. See A1.4.) (Warning - Jet B, extremely flammable. Harmful if inhaled. Vapors may cause flash fire. See A1.4.) should be passed through the monitor during field sampling. The sample volume actually employed shall be reported. See Annex A2 for specific details of sampling practices.
10. Preparation of Apparatus
10.1 Follow the procedure utilizing the apparatus shown in Fig. 2. Alternative apparatus may be used provided that it achieves the same end.
10.1.1 Wash the petri dishes and supports with warm water containing detergent. Then rinse with warm water and finally with distilled water.
10.1.2 Rinse thoroughly with filtered isopropyl alcohol.
10.1.3 Rinse thoroughly with filtered flushing fluid.
10.1.4 Drain for a few seconds, and then air or oven dry.
10.2 Ensure that all glass and plastic tubing attached to the solvent filtering dispenser is clean by flushing thoroughly with filtered flushing fluid.
