MIL-PRF-28750F
4.7.4.2.1 Apparatus. The following apparatus shall be required for this test:
a.
Radioactive tracer gas activation console containing krypton-85/dry nitrogen gas mixture.
b.
Counting station with sufficient sensitivity to determine the radiation level of krypton-85 tracer gas inside the
SSR.
c.
Tracer gas mixture: Krypton-85/dry nitrogen with a minimum allowable specific activity of 100 microcuries
per atmosphere cubic centimeter. The specific activity of the krypton-85/dry nitrogen mixture shall be a
known value and determined on a once-a-month basis as a minimum.
4.7.4.2.2 Procedure. The SSR's shall be placed in a radioactive tracer gas activation tank and the tank shall be
evacuated to a pressure not to exceed 0.5 torr. The SSR's shall then be subjected to a minimum of 10 pounds per
square inch gauge of krypton-85/dry nitrogen gas mixture for 30 seconds. The gas mixture shall then be evacuated in
storage until a pressure of 2.0 torr maximum exists in the activation tank. The evacuation shall be completed in 5
minutes maximum. The evacuation tank shall then be backfilled with air (air wash). The SSR's shall then be
removed from the activation tank and leak tested within 2 hours after gas exposure with a scintillation-crystal-
equipped counting station. SSR's indicating 1,000 counts per minute or greater above the ambient background of the
counting station shall be considered a gross leak failure.
4.7.5 Insulation resistance (see 3.11). SSR's shall be tested in accordance with MIL-STD-883, method 1003. The
following details and exceptions shall apply:
a.
Test condition: E
b.
Points of measurement:
(1)
A common connection of each input circuit and every other isolated input circuit, if applicable.
When specified (see 3.1), a common connection of all input terminals, and a common connection of all
(2)
output terminals. Unless otherwise specified (see 3.1), the voltage shall be 500 volts, and the input
shall be positive with respect to the output.
(3)
A common connection of the terminals of each output pole, and a common connection of all other
isolated output terminals.
c.
Electrification time: 2 `minutes, or until a stable reading is obtained.
4.7.6 DWV (see 3.12). SSR's shall be tested as specified in 4.7.6.1, and when specified (see 3.1), in accordance
with 4.7.6.2.
NOTE:
To avoid unnecessary failures, test voltages shall not be applied indiscriminately. Before beginning
test, short-circuit connections shall be made between any set of non isolated input or output terminals
in which there is a possibility that the SSR will be damaged if the test voltage is applied between
them.
4.7.6.1 At atmospheric pressure. Solid state SSR's shall be tested in accordance with MIL-STD-202, method 301.
The following details shall apply:
Magnitude of test voltage: As specified (see 3.1).
a.
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