MIL-PRF-28750F
4.7 Methods of inspection.
4.7.1 Visual and mechanical inspection. SSR's shall be examined to verify that the interface, external design and
technology, physical dimensions, marking, and workmanship are in accordance with the applicable requirements (see
4.7.2 Screening (Y level only) (see 3.8). SSR's shall be screened in accordance with 4.7.2.1 through 4.7.2.7.
4.7.2.1 Preseal burn-in (optional) (see 3.8.1). SSR's shall be tested in accordance with method 1030 of
4.7.2.2 Internal visual (see 3.8.2). SSR's shall be tested in accordance with method 2017 of MIL-STD-883.
4.7.2.3 Temperature cycling (see 3.8.3). SSR's shall be tested in accordance with method 1010 of MIL-STD-883.
Unless otherwise specified, test condition B shall apply: 100 cycles for qualification inspection and 10 cycles for
conformance inspection.
4.7.2.4 Mechanical shock or constant acceleration (see 3.8.4).
a.
Mechanical shock: SSR's shall be tested in accordance with MIL-STD-883, method 2002, test condition B.
Y1 direction only.
Constant acceleration: SSR's shall be tested in accordance with MIL-STD-883, method 2001, test condition
b.
A. Y1 direction only.
4.7.2.5 Load conditioning (see 3.8.5). SSR's shall be cycled by applying a step function voltage to the input; the
input shall be energized at zero or rated input voltage. The on-state load shall be maximum rated current, without
auxiliary heat sink. Each output circuit shall be loaded with the maximum rated resistive current at the highest rated
voltage, for 3 hours, at a rate no less than 1 operation per second nor more than 30 operations per second. When
applicable (see 3.1), the bias shall be applied at the rated value. The SSR shall be turned off 10 percent of the time
and turned on 90 percent of the time. For single-pole double-throw and double-pole double-throw SSR's, cycling shall
be 50 percent turned on and 50 percent turned off; or for 1.5 hours of test, 10 percent on and 90 percent off, and 90
percent on and 10 percent off for 1.5 hours of test.
4.7.2.6 Interim (pre-burn-in) electrical requirements (see 3.8.6). The interim (pre-burn-in) electrical requirements
may be performed at the option of the manufacturer. Electrical parameters tested shall be those specified in 3.13, as
applicable.
4.7.2.7 Burn-in test (see 3.8.7). Unless otherwise specified (see 3.1), SSR's shall be subjected to 160 +8 hours/ -
0 hours of operation at the maximum operating temperature. At the option of the manufacturer, the burn-in time-
temperature regression table of MIL-STD-883, method 1015, may be used. Lower temperatures at higher load
currents, in accordance with the specified derating curve, may be used with qualifying activity approval. Input and
bias (where applicable) shall be at the rated ON state conditions. The output(s) shall be loaded with the maximum
specified current derated for the test temperature. Output condition shall be monitored with latching failure circuitry
and appropriate indicators. If scanning type condition monitoring is employed, each SSR shall be monitored at least
once per second throughout the entire burn-in period.
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