NSS-PLB 06
NATIONAL SEARCH AND
RESCUE SECRETARIAT PERFORMANCE STANDARD
FOR 406 MHZ PERSONAL LOCATOR BEACON (PLB)
APPENDIX A — ENVIRONMENTAL TEST PROCEDURES
A 1.0 SEQUENCE OF TESTS
All environmental tests shall be conducted in the sequence in which the tests are listed herein. The performance parameters at room ambient temperature (25°?± 5°C) shall be measured at the beginning and end of the environmental tests.
A 2.0 GENERAL TEST CONDITIONS
No adjustments or repairs are permitted to the unit under test throughout the complete test program except for removal and application of primary power as required by the detailed test procedure. All testing, wherever possible, shall be conducted in a manner that does not emit radiation from the test site. Unless otherwise stated, the tests shall be conducted at a temperature of 25°C ± 5°C, except for unavoidable seasonal temperatures for any outdoor tests. A log of battery on-time should be maintained for the PLB being tested. Batteries should not be replaced during a test unless it is probable that the battery on-time will exceed the prescribed operating life time before the test is completed. The test shall be terminated in the case of critical failure.
A 3.0 TEMPERATURE
The temperature gradient, temperature shock, maximum temperature, and operating lifetime at minimum temperature tests shall be performed as defined in C/S T.001.
A 4.0 HUMIDITY TEST
The 10 day aggravated humidity test shall be conducted with the unit in its housing. An additional test shall be conducted on the electronic module(s) of PLBs after removal from the PLB housing.
A 4.1 Procedure
10 day Aggravated
The PLB shall perform to the specification during and after an exposure to constant high humidity environment (>95% RH) while the temperature is cycled between 60°C and 20°C for 10 days. As specified in MIL-STD_810 F Method 507 Aggravated humidity cycle.
Module test
The electronic module(s) shall be exposed to relative humidity in excess of 95% at a temperature of 40°C for a period of eight hours. During this time, the unit under test shall be deactivated with no electrical power applied. At the end of the period, the unit shall be removed from the test chamber to room ambient conditions and any condensed moisture drained off. Within five minutes after removal, the unit shall be activated. Fifteen minutes after activation, the following tests shall be performed in accordance with C/S T.001 and C/S T.007:
- Frequency accuracy;
- Medium and short term stability; and
- RF power output into a 50 ohm dummy load (5W ± 2 dB).
A 5.0 VIBRATION TEST
The PLBs shall be tested in accordance with method 514.4, Category 3 Procedure III of MIL-STD-810E for loose cargo transportation. The PLB shall not activate during exposure to the vibration tests. Following the test, an exterior mechanical inspection shall be performed. The transmitter output test in a 50 ohm load, a frequency accuracy test and a short and medium term frequency stability test shall be performed after a 15 minute warm-up. The PLB shall have failed the test if loose or dislodged components are found, or if electrical parameters become out of specifications.
A 6.0 DROP TEST
The PLB shall be tested in accordance with method 516.4 Procedure IV of MIL-STD - 810E for transit drop. Prior to the drop test the PLB shall be temperature conditioned for a minimum of two hours at -40ºC or -20 ºC. The PLB shall not activate during the test. Document the impact point or surface for each drop and any obvious damage. The drops shall be distributed among all possible faces. Upon completion of the drop tests, an exterior and an interior mechanical inspection shall be performed. The power output test into a 50 ohm load, the frequency accuracy tests and the short and medium frequency stability tests shall be performed 15 minutes after the application of power. The PLB shall have failed the test if loose or dislodged components or cracks on the casing are found.
A 7.0 IMMERSION TEST
The unit shall be turned OFF during the tests. The unit shall be 5ºC warmer than water prior to immersion. The water temperature shall be 18°C ± 2°C. The unit should be submerged at a depth of one meter.
A 7.1 Procedure
The PLB shall be completely submerged for one hour, removed from the water and wiped dry. There shall be no evidence of water leakage into the unit or any of its components. After completion of the submersion test, the unit shall be subjected to the transmitter power output and frequency accuracy tests performed 15 minutes after the application of power to the unit, followed by a thorough mechanical inspection of the unit. The unit shall be opened for inspection. The unit will have failed the test if there is evidence of water leakage into the unit, corrosion, condensation, deterioration of finishes, seals or components.
A 7.2 Acceptability
The test PLB shall be deemed unacceptable if any of the above effects are noticeable.
A 8.0 LOW PRESSURE (Altitude)
The low pressure test shall be performed in accordance with Procedure 1 Method 500.3 of MIL-STD-810E.
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