MIL-PRF-28776/4G
QUALIFICATION INSPECTION:
Qualification inspection and sample size: See table II.
TABLE II. Qualification inspection and sample size. 1/
Single submission
Group submission
M28776/4-038
37 units plus 1 unsealed unit for
37 units plus 1 unsealed unit for
level L at C = 1 2/
level L at C = 1 2/
63 units plus 1 unsealed unit for
63 units plus 1 unsealed unit for
level M at C = 1 2/
level M at C = 1 2/
Qualification inspection as
Qualification inspection as
applicable.
applicable.
M28776/4-033
2 units each PIN.
M28776/4-034
Qualification inspection group l.
M28776/4-035
M28776/4-036
M28776/4-037
M28776/4-039
M28776/4-040
1/ For retention of qualification or extension of qualification to lower failure rate levels, all
life test data accumulated on MIL-PRF-28776/1, MIL-PRF-28776/3, and MIL-PRF-
28776/5 may be used in addition to MIL-PRF-28776/4 data.
2/ The number of units required for qualification testing shall be increased as required in
group Q5 of table II, MIL-PRF-28776, if the relay manufacturer elects to test the
number of units permitting two or more failures. Prior to performance of qualification
inspection testing, the relay manufacturer shall preselect the sampling plan.
Qualification inspection testing for relays supplied with spreader pads (-041 through -048), two (2) units of
the 26.5 volt rated coil voltage (-046) shall be tested as follows:
Perform A1 tests of group A inspection. Relay leads shall be formed and the mounting pad removed.
Perform seal test. Rigidly attach mounting pad to relay. Perform A2 and A3 tests of group A inspection.
Perform visual and mechanical inspection (external).
Group A inspection testing for relays supplied with spreader pads (-041 through -048) shall be tested as follows:
Perform A1 tests of group A inspection. Relay leads shall be formed and the mounting pad removed.
Perform seal test. Rigidly attach mounting pad to relay. Perform A2 and A3 tests of group A inspection.
Perform visual and mechanical inspection (external).
Qualification inspection (reduced testing) and sample size: See table III. If the relays produced for MIL-PRF-
28776/4 are similar in construction and design except for the coils to the relays produced for MIL-PRF-28776/3, then
reduced testing for qualification of MIL-PRF-28776/4 relays may be performed concurrent with or subsequent to
successful qualification of MIL-PRF-28776/3 relays.
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