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|  MIL-D-85859(AS)
The direction of vibration should be vertical to the normal mounting plane
for 5 minutes and lateral to that plane for 5 minutes. Where it is not
feasible to vibrate the distribution box in two directions the vertical
direction shall be used. During the 6-hour period of operations following
the 10-minute vibration period, the distribution box shall be mechanically
cycled periodically through its various phases of operation. Should a
failure occur, it shall be repaired and the test started over, except that
the 10-minute vibration period need not be repeated when it is certain the
failure was not a result of the vibration.
4.5.2 Sampling tests. Distribution boxes selected for sampling tests shall
first have passed the individual tests. Distribution boxes will be selected
for sampling tests by the Government inspector in accordance with table II.
TABLE II.
Sampling test sample selection
Quantity to be Selected
Quantity of Distribution
for Sampling Test
Boxes Offered for Acceptance
First 10
1
1
Next 50
Next 75
1
Next 100
1 for each additional
200 or fraction thereof
4.5.2.1 Scope of sampling tests. As a minimum, each distribution box
selected for sampling tests shall be subjected to the following tests:
a.
Complete operational test at ambient room conditions, making all
necessary measurements to assure that all applicable specification
requirements have been met.
Operational test at certain environmental conditions. The conditions
b.
may vary for each distribution box tested and should be based on
results of the first article, individual, and special tests.
Manufacturing run-in test specified in 4.5.1.3 except that the test
c.
duration shall be 120 hours with no restriction on the number of
failures.
4.5.3 Reliability assurance tests. Reliability assurance tests shall be
conducted in accordance with MIL-STD-781. Tests as required by both the
qualification phase and the production acceptance (sampling) phase shall be
conducted.
Prior to the acceptance of distribution boxes
4.5.3.1 Qualification phase.
under the contract or purchase order, a minimum of three distribution boxes
shall be tested in accordance with MIL-STD-781, under the section entitled
"Qualification Phase of Production Reliability Tests." The maximum number
of distribution boxes to be used shall be those listed in table V of
MIL-STD-781. For the qualification phase, Test Level E shall be used. The
accept-reject criteria for Test Plan IV shall be used.
4.5.3.2 Reliability sampling phase tests. Samples of the distribution box
shall be tested in accordance with MIL-STD-781 under the section entitled
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