ASTM D5452 Standard Test Method for Particulate Contamination in Aviation Fuels by Laboratory Filtration
6. Apparatus
6.1 Analytical Balance, single- or double-pan, the precision standard deviation of which must be 0.07 mg or better.

6.2 Oven, of the static type (without fan-assisted air circulation), controlling to 90 +/- 5°C.

6.3 Petri Dishes, approximately 125 mm in diameter with removable glass supports for membrane filters.

6.4 Forceps, flat-bladed with unserrated, non-pointed tips.

6.5 Vacuum System.

6.6 Test Membrane Filters, plain, 47-mm diameter, nominal pore size 0.8 µm (see Note 1).

6.7 Control Membrane Filters, 47-mm diameter, nominal pore size 0.8 µm. (Gridded control membrane filters may be used for purpose of identification.)

NOTE 1 - Matched weight membrane filters, 47-mm diameter, nominal pore size 0.8 µm, may be used as test and control membrane filters if so desired. Use of matched-weight membrane filters precludes the necessity for carrying out subsequently the procedures detailed in Section 10.

6.8 Dispenser for Filtered Flushing Fluid, 0.45-µm membrane filters to be provided in the delivery line (see Fig. 2). Alternatively, flushing fluid that has been pre-filtered through a 0.45 µm membrane before delivery to the dispenser flask is acceptable.

6.9 Air Ionizer, for the balance case. See Note 2 and Note 3.

NOTE 2 - When using a solid-pan balance, the air ionizer may be omitted provided that, when weighing a membrane filter, it is placed on the pan so that no part protrudes over the edge of the pan.

NOTE 3 - Air ionizers should be replaced within 1 year of manufacture.

6.10 Filtration Apparatus, of the type shown in Fig. 1. It consists of a filter funnel and a funnel base with a filter support such that a membrane filter can be gripped between the sealing surface and the base by means of a locking ring. Use a metal funnel with at least a 70-mm diameter at the top.

6.11 Support Stand, (required when the sample flash point is lower than 38°C) as shown in Fig. X3.1, having adjustable height, integral spill collection pan at the base, and an edge on the can shelf to prevent the can from slipping off. The shelf is slotted. Refer to Fig. X3.1 for fabrication details.

6.12 Dispensing Cap or Plug, (required when the sample flash point is lower than 38°C) with approximately 9.5-mm inside diameter hose barb 32-mm long on which a 75 to 100-mm long piece of fuel resistant, flexible, plastic tubing is installed (see Fig. 1). The plug is for sample containers having 3/4 in. (19 mm) female pipe threads while the cap is for containers having 1.75 in. (44 mm) diameter sheet metal threads. Dispensing spouts for other containers must be fabricated. The closure gasket shall be made of a fuel resistant material. A paper composition material is not acceptable.

6.13 Sample Container, should be a 3.8 to 5-L (1-gal) epoxy lined sample can, preferably the same container in which the sample was collected and should conform to the criteria set forth in Practice D4306. When samples are collected in a smaller container than recommended here, select a container that does not trap particles when the contents are poured out.

6.14 Receiving Flask, shall be glass or metal. A graduated glass flask is preferred so that the space remaining for fuel can be observed. The filtration apparatus is fitted to the top of the flask. The flask shall be fitted with a side arm to connect the vacuum system. The flask should be large enough to contain the sample and flushing fluids.

6.15 Safety Flask, shall be glass containing a sidearm attached to the receiving flask with a fuel and solvent resistant rubber hose and shall be connected to the vacuum system.

6.16 Ground/Bond Wire, #10-#19 (0.912 - 2.59 mm) bare stranded flexible, stainless steel or copper installed in the flasks and grounded as shown in Fig. 1. If a metallic flask(s) is used instead of glass, the flask(s) must be grounded.

6.17 Plastic Film, polyethylene or any other clear film not adversely affected by flushing fluids. Refer to Appendix X4.

6.18 Multimeter/VOM, used for determining whether electrical continuity is 10 ohms or less between 2 points.

7. Reagents
7.1 Purity of Reagents - Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.

7.2 Purity of Water - Unless otherwise indicated references to water shall be understood to mean reagent water as defined by Type III of Specification D1193.

7.3 Isopropyl Alcohol, (Warning - Flammable.)

7.4 Liquid Detergent, water-soluble.

7.5 Flushing Fluids - Petroleum spirit (also known as petroleum ether or IP Petroleum Spirit 40/60), having boiling range from 35 to 60°C. (Warning - Extremely flammable. Harmful if inhaled. Vapors are easily ignited by electrostatic discharges, causing flash fire. See Appendix X2.)

7.6 Filtered Flushing Fluids - Filtered fluids are fluids filtered through a nominal 0.45-µm membrane filter. Filtered flushing fluids are most conveniently obtained by means of the dispenser described in Fig. 2.