4.6.9 Salt fog. The actuator shall be subjected to the salt fog test of
MIL-STD-81O, Method 509.2, Procedure 1. The exposure time shall be 120
hours. Shile subjected to these conditions,the electrical connector plug
shall be suitably protected and the actuator shall be cocked. at the
c o m p l e t i o n of test, the unit shall be tested in accordance wilth 188.8.131.52
and 184.108.40.206 (at room temperature only).
4.6. 10.1 Low frequency and resonant vibration. This information applies to
both the low frequency and resonant vibration tests. The resonant vibration
tests shall be performed in each of the three mutually perpendicular axes, not
in any specific order. All testing shall be completed in one axis prior to
testing in the next axis. The low frequency vibration test shall be conducted
in the one direction as indicated. The test parameter tolerances shall be as
floolws: Amplitude: ± 10%, frequency: ± 2% or 1/2 Hertz (Hz) below 20
Hz, acceleration: ° 10%. The actuator shall be mounted to the vibration
exciter table by means of a rigid fixture utilizing the mounting area as
intended by the applicable drawing. The control accelerometer shall be
mounted on the test fixture, adjacent to the mounting area of the actuator.
Inadvertent actuation of the actuator plunger, failure of the actuator to
function, or structural damage to the actuator shall be cause for rejection.
220.127.116.11 Low frequency. The actuator, in the cocked position, shall be
subjected to a sinusoidal vibration sweep test within the frequency range of 8
to 50 Hz. The test level shall be 0.060 double amplitude (D.A.) and the sweep
time shall be 30 seconds. The vibration excitation shall be applied at right
angles to the switch housing and plunger travel. At the completion of the
vibration sweep, specifically at 50 Hz, the actuator shall be vibrated for an
additional 30 seconds. At this time, the actuator shall be activated
utilizing 28 VDC.
18.104.22.168 Resonance search. The actuator shall be subjected to a sinusoidal
vibration resonance search in each of the three mutually perpendicular axes.
The frequency range shall be 8 to 2,000 Hz. The test level shall be 0.060
D.A. or 10g's whichever is less. The sweep time shall be 1 octave per
minute. All resonant frequencies shall be determined. This test shall be
conducted with the actuator in each of its two modes; cocked and uncocked. At
the completion of each resonance search test, the actuator shall be activated
utilizing 28 VDC.
22.214.171.124 Resonance dwell. The actuator shall be subjected to a sinusoidal
vibration resonance dwell test in each of three mutually perpendicular axes.
The test level shall be 0.060 D.A. or 10 g's whichever is less. The total
number of cycles in each axis shall be 540,000 cycles. The number of cycles
shall be divided equally among the resonant points determined in 126.96.36.199 (see
example). The actuator shall be vibrated at the four most severe resonant
frequencies. If no resonant frequencies are noted, the actuator shall be
vibrated at 50 Hz for 3 hours in each axis. The test shall be repeated for
each of the two actuator modes, cocked and uncocked. The total test time
shall be 18 hours for the 50 Hz dwell test.