User's Manual

MIL-PRF-46374G
13
4.6 Test methods.
4.6.1 Crystals. Crystals shall be examined after assembly to the case and after being subjected to
the storage environment of table I to determine compliance with 3.4.6.
4.6.1.1 Crystal strength test. The crystals shall be functionally tested as follows: The case
assembly, including crystal, shall be placed flat, crystal up, on a rubber sheet 0.5 mm (0.02 inch)
thick, placed on a horizontal, rigid nonresilient, metal surface. A solid steel sphere weighing 15.7
± 1.4 grams (0.55 ± 0.05 ounces) and 1.6 cm (five-eighths of an inch) in diameter shall then be
freely dropped so as to fall 30.5 cm (12 inches) before striking the crystal. Any visible damage to
the crystal shall be cause for rejection.
4.6.2 Strap. The strap shall be examined for compliance with 3.4.7.
4.6.3 Case.
4.6.3.1 Battery servicing. The case shall be visually inspected to determine the conformance to
3.4.9.1. A physical test shall be applied where case parts are not capable of being removed to
determine conformance to 3.4.9.1. The physical test shall consist of applying a force or prying
under normal pressure (equivalent to 40.5 ± 4.5 N (9 ± 1 pounds) direct force) in such a manner
that no marking or scarring of the case and case finish shall result.
4.6.3.2 Finish and color. The case shall be visually inspected to determine the conformance to
3.4.9.2.
4.6.4 Radiological.
4.6.4.1 Contamination. Completed watches shall be checked for contamination in accordance
with 3.6.1. A Metricel GN-6 or equivalent wipe, moistened with deionized or distilled water,
shall be used to wipe the watches. All exterior surfaces of the completed watch shall be
thoroughly wiped. The wipe shall be placed in the liquid scintillation solution within
1 minute after wiping each watch. The amount of radiological contamination on the wipe shall be
determined using a liquid scintillation counting technique. Results indicating removable
contamination over the entire watch of more than 100 dpm shall constitute failure of this test.
4.6.4.2 Diffusion and water leakage. Completed watches shall be checked for diffusion in
accordance with 3.6.3 and water leakage in accordance with 3.5.5. They shall be submerged in a
measured volume of distilled or deionized water, equal to approximately 10 times the volume of
the watch, for 24 hours at 23 °C ± 1 °C (73 °F ± 3 °F). Watches shall be removed from the
water. This is the test procedure for radiological diffusion, and if the radioactive content of the
water exceeds 50 nanocuries per 24 hour period, it shall constitute failure of the test. The
watches shall also be examined for water leakage, and if there is water in the crystal bowl at the
completion of the test, it shall constitute failure of the water resistance test. Failure of watches in
either of these tests shall be cause for refusal by the government to continue acceptance of the