FED-STD-228A
4.2.2 The specimen shall then be weighed as described in 4.1.2 and immersed in the water bath at a
temperature of 70° ± 2°C (158° ± 4°F) for a period of 166 hours. At the end of the exposure period, the
specimen shall be transferred to a similar bath of distilled water at a temperature of 24° ± 3°C (75° ± 5°F).
The specimen shall be allowed to remain in this bath for not less than 5 minutes nor more than 15
minutes. The specimen shall be removed from the bath and shaken to remove loose surface water. The
remaining surface water shall be removed by blotting lightly with clean, lintless, absorbent gauze and the
specimen weighed as described in 4.1.5. The specimen shall be dried, cooled, and weighed as
described in 4.1.6.
5. RESULTS
5.1 Calculation.
5.1.1 The area of the immersed portion of the specimen shall be calculated as follows:
Conductor size No. 1 AWG or smaller:
Area, S square inches=C x L
where:
C=the circumference of specimen before bending, inches.
L=the length of the immersed specimen, inches.
Conductor size No. 0 or larger:
Area, S square inches=2(L x W)+2T(L+W)
where:
W = the width of the specimen, inch.
L = the length of the specimen, inch.
T = the thickness of the specimen after buffing, inch.
5.1.2 The moisture absorption of the specimen shall be calculated as follows:
Where the original weight W1, is less than the final weight, W3, of the dried specimen:
Moisture absorption per square inch grams= W2-W1
S
Where the original weight W1, is greater than the final weight W3, of the dried specimen:
Moisture absorption per square inch, grams = W2-W3
S
where:
W1 = the original weight of specimen, grams
W2 = the weight specimen after immersion, grams.
W3 = the weight of the specimen after final drying, grams.
S = the area of immersed portion of specimen, square inch.
5.2 Unless otherwise specified in the detail specification, three specimens from each inspection unit shall
be tested.
5.3 The moisture absorption of the insulation of the inspection unit shall be the average of the results
obtained from the specimens tested.
5.4 Moisture absorption of the insulation of the inspection unit shall be recorded to the nearest 0.01 gram
per square inch.
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