AThis specification covers two types of dummy converters \(electrical capacitors\) having a capacitance equivalent to an empty 10-liter and 25-liter liquid oxygen converter.

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MIL-PRF-26392E

II dummy converters.

4.6.4 Capacitance at high temperature. The dummy converter shall be maintained at a

temperature not less than 260�F for no less than 8 hours. While still at this temperature, the

capacitance shall be measured and shall be 123.5 � 1.0 pF for Type I dummy converters and

303.5 � 2.5 pF for Type II dummy converters.

4.6.5 Case leakage. The dummy converter, in normal operating configuration, shall be

heated to 113� � 5�F and maintained at this temperature for no less than 2 hours. The dummy

converter then shall be immersed in water at 64�� 9�F to a depth of 36 � 5 inches for 2 hours.

Any evidence of water penetration into the dummy converter shall be a cause for rejection.

4.6.6 Reliability. This test shall be conducted with sufficient duration to obtain a 90%

confidence that a MTBF of 300 hours has been achieved. This test may also be used to

demonstrate a MTBF of 200 hours and a 99.33% probability of completing a 2-hour mission.

The dummy converter shall be stabilized at a temperature not greater than -65�F, then raised to a

temperature not less than 260�F and held for no less than 2 hours. After 2 hours, the temperature

shall be reduced to not greater than -65�F. The cycling time between temperature extremes shall

be not greater than 40 minutes. The dummy converter shall be subjected to not less than four of

these temperature cycles every 24 hours. The dummy converter shall be subjected to vibration at

a frequency between 20 and 60 Hz and an applied acceleration of � 2g for not less than 10

minutes during each hour of this test. The rated voltage within � 2% shall be applied

continuously during this test. The dummy converter shall be checked at least once every 24

hours at each temperature extreme to determine if a failure has occurred. No parts shall be

replaced as preventive maintenance during reliability testing. A failure shall be identified as any

malfunction that causes a failure in the capacitance value of the dummy converter.

4.6.7 Maintainability. Completion of corrective maintenance tasks within 1 hour

(field level only) for expected failures shall demonstrate compliance with the

maintainability requirements.

5. PACKAGING

5.1 Packaging. For acquisition purposes, the packaging requirements shall be as

specified in the contract or order (see 6.2). When packaging of materiel is to be performed by

DoD or in-house contractor personnel, these personnel need to contact the responsible packaging

activity to ascertain packaging requirements. Packaging requirements are maintained by the

Inventory Control Point's packaging activities within the Military Service or Defense Agency, or

within the military service's system commands. Packaging data retrieval is available from the

managing Military Department's or Defense Agency's automated packaging files, CD-ROM

products, or by contacting the responsible packaging activity.

6. NOTES

(This section contains information of a general or explanatory nature that may

be helpful, but is not mandatory.)