JSS (Revision No. 1) MINISTRY OF DEFENCE JOINT SERVICES SPECIFICATION ON ENVIRONMENTAL TEST METHODS. JSS , knowns as the Penta-Five test, is an antifungal product test for electronics. JSS Revision No. 1. LIST OF MEMBERS ASSOCIATED WITH FORMULATION OF THIS STANDARD. 1. This Joint Services Specification has.
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It should begin as early as practicable in the development phase and continues as the design matures. For non hermetically sealed itemsthe equipments shall be disassembled and examined for effects of acid corrosion. Final measurement see clause 3. The characteristics required of the vibration generator and fixture when loaded for the conditioning process shall be as follows Basic motion Basic Motion The basic motion shall be sinusoidal and such that all the fixing points of the equipment are moving substantially in phase and in straight parallel lines, except as in 2.
The temperature of the chamber shall then be restored to laboratory atmospheric conditions. These fixtures shall be such as to enable the equipment to be subjected to an acceleration in the direction or directions as specified.
The frequencies at which significant response peaks occur shall be identified 6 db amplification of input level considered significant.
For non hermetically sealed items, the equipment shall be disassembled and examined for effects of alkaline corrosion.
Out of the equipment are vulnerable to ESD effects and hence should be subjected to test. Random vibration as specified in para 4. The air in the chamber shall be continuously agitated but not so vigorously as to cause 001 cooling of the equipment under test.
The acid mist shall freely circulate aground the equipment under test. The missile system shall be electrically and mechanically checked as specified.
Equipment intended kss use with isolators should normally be tested with its isolators. The relevant equipment specification shall specify the applicable pulse shape. The performance achieved shall be noted in the report. However, this requirement is not applicable in case of EEDs. The composition of the solution shall be 0.
Power supply to DUT and test, instrumentation iss be from different phases and through suitable isolation transformers. The vibrations and shock encountered on the applicable operating surfaces shall not cause the brakes to engage.
Conditioning The equipment shall be subjected to this test in its unpacked and switchedoff conditions. The equipment normally operated throughout the flight shall be operated from the start of the temperature conditioning and shall continue to operate throughout this step. If in the course of initial 0526 search, low frequency high Q resonance have been found a check should be made that the sweep rate of one octave per minute is not too great.
For deployment in vehicles either relevant sinusoidal or random vibration can be selected as specified. Characteristics of the Shock Machine When the equipment together with its supporting brackets and any other load for test purposes are mounted on the shock machine, the applied shock shall, at the monitoring point, have following characteristics.
Where equipments are deployed in both tracked and wheeled vehicles, the levels appropriate tracked vehicles shall apply. The relevant equipment specification shall choose the appropriate values from those listed in 4.
An agent based on N methyl tauride Igepon or on dioctyl sodium sulphoccinate is suitable. Where f is the natural frequency in Hz, and Q is the amplification factor. At the beginning of the test the equipment shall be in its Switched off” conditions. For this purposethe volume of the test chamber should preferably be not less than eight times the volume of the equipment under test.
Initial measurements see 3. For heat dissipating equipment it is necessary to make repeated measurements to ascertain in interval of time required for the temperature to change3 deg c or as otherwise specified.
When humidity conditions in the chamber are obtained by using dematerialized water, this shall have a resistively of not less than ohm 026.
A demonstration of the functional performance of the equipment should be made towards the end of the conditioning phases or if desired at the start and 0526 intervals throughout only, the performance check should be carried out after the noise conditioning. The equipment shall be mounted as in 3.
The one third octave band sound pressure level about the entire equipment shall be shaped so that ,at the location of each of these reference planes, the frequency spectra, profile shall conform to the frequency spectral profile given in Fig 4.
JSS_ – Documents
The equipment shall then be removed from the chamber and shall be examined for corrosion and deterioration of metal partsfinishes, materialscomponents and contacts materials.
During the test carry out performance check as specified. Any deviation from normal test procedure. Temp corresponding to height h.
The temperature and R. The sweep will be carried Hz in 15 minutes for each axis: The equipment shall be maintained at this temperature for a period of 3 hours. These sensors shall be centrally located within the test chamber, where possibleor in the return air stream and shall be baffled or otherwise protected against direct impingement of supply air and against direct impingement of supply air and against radiation effects.
Two procedure are specified for this test. The mounting fixtures shall be such as to enable the specimen to bevibrated along the various axes specified for conditioning.