 |
|||
|
Page Title:
Reliability Index Determination |
|
||
| ||||||||||
|
|  MIL-T-81809(AS)
The test sets shall be vibrated (without vibration isolators) for a period of 10
minutes prior to the beginning of the 6-hour period of operation. Where feasible,
the test sets shall be operated during this vibration period for the purpose of
detecting flaws and imperfect workmanship. Operation within the specified limits of
satisfactory performance is not necessarily required during the vibration period.
The direction of vibration should be vertical to the normal mounting plane for 5
minutes and lateral to the plane for 5 minutes. Where it is not feasible to vibrate
the test set in two directions the vertical direction shall be used. During the 6-
hour period of operation following the 10-minute vibration period, the test sets
shall be mechanically cycled periodically through their various phases of operation.
Should a failure occur, it should be repaired and the test started over, except that
the 10-minute vibration period need not be repeated when it is certain the failure
was not a result of the vibration. Should repetitive failures occur, corrective
action shall be taken to eliminate this defect from future test sets. A record
shall be kept of all failures. The 6-hour period specified above may be composed of
two 3-hour periods to conform with standard working hours.
4.4.4 Environmental Tests - (M102) Environmental tests shall be conducted as
specified in MIL-T-S422 to the limits as specified in MIL-T-21200 for Class 2 equip-
ment. In addition the test set case and cover shall be subjected to the drop and
water-tightness test specified in MIL-T-21200,
4.4.5 Reliability Index Determination - (M101) The test sets shall be sub-
mitted to the reliability index determination tests as specified in MIL-R-22973,
Test Level II, except the temperature shall be 25 + 5 Centigrade.
4.4.5.1 Length of Tests - The total unit hours of test, not including any burn-
in period, shall be 1750 hours, or until 10 failures have occurred.
4.4.5.2 Duty Cycle - The test set shall operate continuously on a 24-hour
operating cycle as follows:
Operating Time
Test Set
Switch
(Hours]
Operation
Positions
S4
S2
S3
S1
16
RECHARGE
OFF-RECHARGE
ON
OFF
2
BATTERY MODE
4
LIGHT-MOTION
Not Applicable
A-C Mode (See Note)
4
OFF-RECHARGE
ON
ON
3
NOTE: The 4-hour time shall include the time required TO
measure the performance characteristics specified in 4.4.5.3.
4.4.5.3 Performance Characteristics to be Measured - During the test the follow-
ing performance characteristics shall be measured at the end of every a-c mode of
operation cycle specified in 4.4,5.2.
10
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals