MIL-DTL-17902G(SH)
4.5.8.4.2 Procedure. The resistance to ozone shall be measured by the procedure specified in ASTM D1149.
The specimen shall be clamped firmly at the ends in the holder at 20 percent extension and placed in an oven for
16 to 24 hours at 100±2 °F. After this preliminary exposure period, the specimen shall be placed in an ozone
chamber at 100±2 °F with an ozone-air atmosphere of 1.00±0.05 parts of ozone per one million parts of air by
volume. After exposure for 166±½ hours, the specimen shall be removed from the ozone chamber and examined for
surface cracking with a 7X magnifying lens. Cracks in the rubber within ⅛ inch of the clamps shall be ignored since
they may be due to excessive strain in this region.
4.5.8.5 Nonvolatile extract.
4.5.8.5.1 Test specimen. The specimen shall consist of strips of the hose tube about 1/16 inch wide by 1/16 inch
thick by 1½ inches long cut from the sample hose specified in 4.3.2.2. The total weight of strips shall be about
5 grams. Duplicate specimens shall be tested.
4.5.8.5.2 Procedure. This test shall utilize the procedure specified in ASTM D471, for "Procedure for
Determining Mass of Soluble Matter Extracted by the Liquid", where a weighted specimen shall be placed in an
extraction thimble, then inserted in a siphon cup of an extraction apparatus. One hundred milliliters of Reference
Fuel A of ASTM D471 shall be added to the extraction flask. Extraction shall be carried out for 46±½ hours at such
a rate that 2½ to 3 minutes are required to fill and empty the syphon cup. The specimen and flask shall be rinsed
with 25 milliliters of fresh fluid, and the wash added to the extract. The nonvolatile residue from the extract shall be
determined in accordance with ASTM D381, except that the evaporation time shall be 45 minutes. The weight of
the residue shall be expressed as percent of the original weight of the specimen. The results of duplicate tests shall
be averaged.
4.5.8.6 Saybolt color number. The specimen shall consist of a 15-inch length cut from the sample hose
obtained as specified in 4.3.2.2. The specimen shall be sealed at one end, filled within 2 inches of the top with
Reference Fuel B of ASTM D471, and capped to prevent evaporation or adulteration by extraneous material. A
suitable arrangement is shown on figure 7. After 168±2 hours, the Saybolt color number of the fluid extract shall be
determined in accordance with ASTM D156. Two duplicate tests shall be performed and the results averaged. The
Saybolt color number of the uncontaminated medium number 6 used shall be plus 25, minimum.
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