4.6 Test methods and procedures.
4.6.1 Storage temperatures.- The telescope shall be exposed to the
temperatures specified in 3.3.1, utilizing test equipment in accordance
with the "Test Facilities" requirements of Specification MIL-F-13926.
This equipment shall be capable of maintaining the specified temperatures
until thermal stabilization is reached. The temperature shall be changed
gradually to avoid thermal shock. After the telescope has been exposed
to each extreme temperature and returned to standard ambient temperature,
the telescope shall be inspected for evidence of damage or deterioration.
The telescope shall then be subjected to examination and the tests herein
to determine compliance with all accuracy requirements of this specifica-
4.6.2 Operating temperatures.- The telescope shall be subjected to
the temperatures specified in 3.3.2, utilizing the test facilities
referenced in 22.214.171.124. The temperature shall be changed gradually to
avoid thermal shock. When the telescope has been thermally stabilized
at each extreme temperature it shall meet the requirements of 3.9 to
126.96.36.199, inclusive. Upon return to standard amibent temperature, the
telescope shall be tested in accordance with all remaining tests specified
herein to determine compliance with respective requirements referenced
in each test.
4.6.3 Vibration.- The telescope shall be mounted on a vibration
machine equipped with facilities to securely hold the telescope while the
machine is in motion. The telescope shall be vibrated in accordance with
3.3.3 at the amplitude and for the period of time specified. Subsequent
to vibration, a visual examination shall be made to determine evidence
of physical failure or damage and the telescope shall then meet all re-
quirements as defined in 3.3.3.
4.6.4 Sealing (optical assembly area).- The optical assembly portion
of the telescope shall be pressurized internally to the psi value specified
in 3.4.1 with dry nitrogen for the length of time specified in 3.4.1. While
under pressure, the optical assembly portion shall meet the requirement
specified in 3.4.1. Leaks can be determined by using a pressure gage
graduated in tenths of a pound (psig) or by using Pressure Testing Fixture,
Two Station - 8665556.
188.8.131.52 Sealing (counter box area).- The counter box portion of the
telescope shall be pressurized internally to the psi value specified in
3.4.2 with dry nitrogen for the length of time specified in 3.4.2. While
under pressure, the counter box portion shall meet the requirement
specified in 3.4.2. Dry nitrogen used in this test to have a dew point
of at least -25°F. Accuracy of the test equipment used for this test shall
be equal to or exceed the accuracies depicted on Pressure Tester Drawing
This test to be performed on each telescope.