MIL-R-835168
c. Measurements at each operating temperature extreme: During steps 1 and 3 of the fifth cycle at the end of each temperature exposure, and with the relays still in the conditioning chamber, the insulation resistance, pickup and dropout voltages (as applicable, see 3.1), and operate and release times (as applicable, see 3.1) shall be measured as specified in 4.6.7, 4.6.10, and 4.6.13, respectively.
d. Examination after test: Relays shall be visually examined for evidence of cracking, peeling, and flaking of the finish.
4.6.3 Run-in (see 3.6). Relays shall be preconditioned prior to run-in by performing a dry buzz of contacts for a minimum of 5 million cycles under no load conditions. Contacts shall not be monitored during dry buzz. Following dry buzz, run-in shall be performed for a minimum of 1 million cycles with the following loads:
a. The coil shall be energized at rated voltage.
b. Test load for qualification inspection, 5 V dc at 10 mA; test load for group A inspection, 0.05 V dc at 10 mA.
During run-in, each pair of mated contacts shall be monitored for contact resistance as specified in 4.6.3.1 or
4.6.3.2.
4.6.3.1 Noncontinuously monitored test. Contact resistance shall be measured as a voltage drop across the
relay while the contacts are held closed and while test load current is being carried by the contacts. An oscilloscope shall be used to monitor opening and closing of the contacts under static load conditions to determine welding or
sticking of the contacts. For life testing the number of cycles at which the above characteristics are monitored shall be 18,000, 36,000, 54,000, 72,000, 90,000, 1 x 106, 5 x 106, and every 5 x 106 thereafter until the end of tests. For group A testing the number of cycles at which the above characteristics are monitored shall be 15,000, 30,000,
45,000, 60,000, 75,000, 90,000, and 1 x 106. Contact resistance for life testing and group A testing shall be measured as specified in 4.6.12.
4.6.3.2 Continuous miss detection test. Relays shall be monitored for stick fault failures each time the contacts open or close. If the contacts fail to open in 1 ms (1.5 ms for form C contacts) after the coil drive is removed, a stick fault shall be detected and indicated. The contact resistance level shall be monitored for a period of 50 percent of coil "on" time and if the contact resistance exceeds the values specified in 3.15, a contact resistance miss will be
detected and indicated.
4.6.4 Contact stability (see 3.7). The coil shall be energized and deenergized for 10 consecutive cycles. After each operation, contact resistance shall be measured and the maximum difference between the 10 measured values of contact resistance shall not exceed 0.005 ohm.
4.6.5 Solderability (applicable to relays with solder terminals) (see 3.8). Relays shall be tested in accordance with method 208 of MIL-STD-202. The following details and exception shall apply:
a. Number of terminations of each part to be tested: All.
b. Depth of immersion in flux and solder: Leads shall be immersed to within .0625 inch (1.59 mm) of the molded package.
c. Temperature of molten solder: Shall be a uniform 260°C ±5°C (500°F ±9°F).
4.6.6 Dielectric withstanding voltage (see 3.9). Relays shall be tested in accordance with method 301 of MIL-STD-
202. The following details shall apply:
a. Points of application and magnitude of test voltage: Shall be as specified (see 3.1). b. Maximum leakage current: 1.0 mA.
c. Duration of application of test voltage: 60 seconds for qualification inspection; 5 seconds for group A
inspection.
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