FED-STD-228A
Method 4001.1
18 APRIL 2014
RESISTANCE TO HEAT, OXYGEN, AIR, LIGHT, AND OZONE; GENERAL
1. SCOPE
1.1 This group of tests is intended for use in determining the relative resistance of rubber and rubber-like
insulating and jacket compounds to deterioration influence by heat, air, light, oxygen, and ozone. These
tests consist of exposing specimens from rubber and rubber-like compounds, having previously
determined physical characteristics, to controlled deteriorating influences for a specified period of time
after which time the same physical characteristics of the compound are again measured. Changes in
tensile strength and elongation are most commonly used to indicate the degree of deterioration and,
unless otherwise specified in the detail specification, these tests should be used.
1.2 The results obtained from tests in this group are comparative only and should be evaluated against
the performance of insulation and jacket compounds of known natural and accelerated aging
characteristics. The results of accelerated tests should not be used alone to predict or estimate the
natural life of these materials.
2. SPECIMEN
2.1 The specimen should be as described in the method of test used for determining the specified
characteristics of the compound before and after aging. If tensile strength and elongation are used to
measure the deterioration, the specimen should be as described in methods 3021 and 3031, respectively.
2.1.1 The physical characteristic of the insulating and jacket compound should be determined as
described in the required method of test. Specimens should then be exposed to the conditions specified
in the detail specification, the same characteristic again determined and the change in the characteristics
calculated. If it is not necessary to destroy the specimen in determining the initial characteristic of the
compound, the same specimen should be exposed.
2.1.2 If changes in tensile strength and elongation are used as a measure of deterioration, these
characteristics of the compound should be determined as described in methods 3021 and 3031
respectively. Additional specimens should be prepared, measured, and exposed to the conditions
specified in the detail specification. The tensile strength and elongation of the exposed specimens shall
then be determined as described in methods 3021 and 3031 respectively, and the change calculated.
Unless otherwise specified in the detail specification, the tensile strength after aging should be based on
the cross-sectional area of the unaged specimen.
2.1.3 Unless otherwise specified in the detail specification, bench marks for determining elongation of
aged specimens should be placed on the specimen after aging.
2.1.4 If buffing of the specimen is necessary, it should be done before exposure.
3. PRECAUTIONS
3.1 The following precautions shall be observed in conducting accelerated aging tests:
3.1.1 The contents of the oven, bomb, or other container in which the specimens are exposed shall be
restricted to specimens known to be of the same composition.
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