FED-STD-228A
4.3 After adjusting the immersion oil to the required temperature, the specimen shall be completely
immersed so that the liquid can circulate freely around the specimen during the period of exposure. The
immersion container shall be fitted with a reflux condenser and the specimen exposed for the required
time at the required temperature.
4.4 At the end of the immersion period the specimen shall be removed from the liquid, placed
immediately in a fresh supply of the same liquid at room temperature, and allowed to remain for 35 ± 5
minutes.
4.5 At the end of the cooling period in the fresh liquid, the specimen shall be removed from the liquid,
quickly dropped into acetone, and blotted lightly with filter paper. Unless otherwise specified in the detail
specification, tensile strength and elongation shall be determined of the aged specimen as described in
methods 3021 and 3031. If other properties are required the specimen shall be tested as described in the
specified method. The same tests shall be conducted on aged and unaged specimens for the purpose of
comparison in determining the degree of deterioration of the aged material.
4.6 The specimen shall be tested within 3 minutes after it has been removed from the cooling liquid. (See
4.4)
5. RESULTS
5.1 Calculation. The change in tensile strength, elongation, or other characteristic of the insulation or
sheath of the inspection unit due to aging shall be calculated as follows:
Change in characteristic, percent=O-E x 100
O
where:
O=the value obtained on the unaged insulation or sheath of the inspection unit.
E=the value obtained on the aged insulation or sheath of the inspection unit.
5.2 Unless otherwise specified in the detail specification, the number of specimens tested from each
inspection unit shall be as required in the method of test, 4.2, used for determining the deterioration of the
insulation or sheath.
5.3 The change in the characteristic of the insulation or sheath of the inspection unit shall be recorded to
the nearest 1 percent.
5.4 The temperature and time of exposure shall be recorded.
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