JSS Revision No. JSS , knowns as the Penta-Five test, is an antifungal product test for electronics. This Joint Services Specification has. Captive flight endurance test levels and duration of test see 3.
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Date to : Sl. SCOPE 2 2. Other technical enquiries should be referred to the Director , Directorate of Standardization, Ministry of Defence , New Delhi — It dose not apply to support equipment. The tests described herein are not to be interpreted an exact and conclusive representation of actual operational and storage conditions. It is also the purpose of this document to standardize environmentalists in order to obtain, as much as possible ,reproducible test results.
In some of the tests, the test conditions are varied in order to enable the designers select the conditions which will be adequate to meet the users qualitative requirements , commensurate with the design efforts. The relevant equipment specification shall define the acceptable performance limits during and after the specified environmental tests.
Such instructions, together with the incidence and grouping of equipments for tests for the purposes of design approval and the acceptance inspection shall be specified in the relevant equipment specification. While conducting any test described in Section 4 of this specification, standard procedures and conditions of tests shall be followed see 1.
In such cases the details shall be as given in the relevant equipment specification. NOTE 1 : In practice it is taken as the average of temperatures measured at a number of points in a horizontal plane through a point 0 mm to 50 between the equipment and the wall of the tes chamber or at 1 m distance, whichever is less. NOTE 2 : IF forced circulation is used in the testing of heat dissipating equipment, the concept of ambient temperature is no longer valid.
Under these conditions, the testing should be based these conditions, the testing should be based on the specification of the surface temperature or the requirements of the relevant equipment. NOTE : Final measurements made at the end of test may be taken as the initial measurements of the subsequent test.
NOTE : Measurements required to prove that an equipment can be regarded as non- heat dissipating , can be made in normal laboratory conditions , if care has been taken that no outside influence for example , draughts or sunlight affects the measurements. Where called for ,it is the first process in the test procedure.
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. Temperature stability has been reached when the ratio between consecutive intervals exceeds 1. NOTE 1 : where the thermal time constant of the equipment is short compared with the duration of the exposure to a given temperature , no measurement is needed. NOTE 2 : Where the thermal time constant of the equipment is of the same order as the duration of the exposure ,checks should be made to ascertain;A.
NOTE : In practice , it may not be possible to make direct measurements of the internal temperature of the equipment. A check may then made by measuring some other parameter which is temperature dependent and for which the law of temperature dependent is known. During the visual examination of the equipment, defects in construction, the presence of foreign bodies, moisture, dust ,etc. NOTE : No requirement for relative humidity is given because its correction by calculation is generally not possible.
In such cases , the actual values used shall be given in the test report. NOTE 2 : The limits of variation of temperature and relative humidity carried during a series of measurements carried out as part of one test on any equipment shall , if necessary , be specified in the relevant equipment specification. It is , therefore , essential to refer ,before caring out a test , to the relevant equipment specification , to ascertain , if any modifications , have been in the test conditions.
For this purpose , the volume of the test chamber should preferably be not less than eight times the volume of the equipment under test. These sensors shall be centrally located within the test chamber, where possible , or 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.
The air in the chamber shall be continuously agitated but not so vigorously as to cause undue cooling of the equipment under test. Most of the equipments have restricted sphere of use which , by limiting the severity conditions of use , may aloe simplification of the design with the restaurant reduction in cost.
The severity under various conditions largely depend on their deployment conditions, role for which it is designed , the location of the equipment in the missile , and factors like permissible modes of transportation. Conventional classification based on range , role etc. For example a short range missile like anti call for high altitude test ,if permitted to be airlifted. Even then it will be desirable that the containers with missiles in positions are tested for the altitude and rapid temperature cycling.
Applicability for a particular equipment is to be decided by the designer in consultation with users and inspection Authority taking all relevant factors into account. Guidance for selection of levels will be given appropriately in this document for selection. Group I Missiles frame , propulsion , liquid systems Hydraulic systems ,gas systems and mechanical equipment having only mechanical Equipment having only mechanical operating parts.
Group IV Control Equipments , Sensors , guidance equipment including accessories but not electronic ,optical and electro optical instruments.
High Temperature 1 3 1 1 3 -. Tropical Exposure 6 6 2 3 13 - Note 3 5. Temperature shock 4 4 - 5 12 -. Corrosion Acid 9 9 - 7 14 - Note 1,2,3 Corrosion Alkaline 10 10 - 8 15 - Note 1,2,3 Corrosion Salt 11 11 4 9 16 - Note 1,2,3 Acoustic Vibration 20 20 - 18 11 7. Acceleration 13 13 12 16 4 5 Steady State Aero Dynamic - - - - - 1 heating Shock Note 1 14 14 10 15 15 -. Impact Note 1 15 15 11 12 7 -. Note 2 : For sealed equipment this test may be applied only to components and finishes located outside the seal.
Note 4 : Combination of above tests may be resorted to by the designer , if required. Performance check shall be carried out at the end of each phase the maximum surface temperature attained by the component or materials in the equipment shall be measured and recorded, if required.
The performance check shall be carried out during the last 30 minute of the period specified. The chamber temperature shall be restored to test conditions after performance check. In addition , the chamber shall also be capable of meeting all the requirements specified for test chamber for the high temperature test Test Number 1 and the low temperature test Test no 2.
Two procedure are specified for this test. After test chamber conditions are stabilized , maintain these test conditions for one hour. At the end of this period , the test item shall to the extent possible , be visually inspected for presence of deterioration which would impair future operation. The performance check shall be carried out on the equipment as required. Adjust the chamber temperature to the corresponding temperature given in Table 4. Maintain the condition for 3 hours.
Adjust the chamber temperature corresponding to the test conditions chosen as given in Table 4. Maintain the condition for 1 hour. The equipment shall then be operated as specified. Note 1 : 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.
Note 2 : The equipment operated intermittently in flight shall be operated only when required conditioning has been done and equipment has achieved stable temperature. Maintain the temperature corresponding to the test condition, depending on the altitude ceiling for operation. Carry out the performance check as specified. It is usually continued for at least half an hour after equipment has commenced functioning or performance check is completed whichever is longer.
Note 3 : All measurements shall be made simultaneously at the end of warm up period where this is practicable, characteristics likely to be affected by low temperature should be checked. Note : A saturated atmosphere conforming to these requirements shall be accepted without humidity measurements, if heating is by steam injection. During this period the equipment shall be operated and performance check carried out as specified.
This shall constitute one cycle. At the end of last cycle, atmospheric conditions and the equipment shall be subjected to recovery conditions. Note : In case of Procedure 2, the equipment shall be completely stripped and examined for ingress of moisture if so required. Saturation of the chamber atmosphere with water vapour shall occur during this period. Note : Condensation may occur during the cooling period but water shall not drip on to the equipment from the roof of the chamber. The total number of cycles shall correspond to one of the following test conditions, as required.
Notes : The equipment shall be normally subjected to the test condition C. If required, the relevant equipment specification may extend the test duration to 56 Cycles, corresponding to test condition D, in case of fully exposed equipment. Test conditions A and B may be specified for protected and partially protected equipments.
The relative humidity during this period shall not exceed 3 percent. The time taken shall not exceed 6 minutes, unless otherwise specified. The time for transfer shall not exceed 6 minutes, unless otherwise specified. When relevant equipment specification requires conditioning for more than one cycle, the steps given in para 3. The simulated radiation shall have the following spectral distribution. The relative humidity during this period shall not exceed 50 percent.
During the last 3 hrs of this period, the radiant energy shall be increased unit only from zero level to the maximum see 3. The radiant energy shall be maintained at a maximum level during this period. During this period in the first 3hours the radiant energy level shall be uniformly reduced to zero. Note :- The radiant energy during the conditioning specified in 3.
Use of such shower head will result in water consumption of approximately liters per hour at a static pressure of kpa. Un representative , coating and contaminants such as oils , grease and dirt , which could affect the adhesion between the ice and the surface of the equipments, shall be removed before commencing the test.
Specified for the test chamber in high temperature test. Test Number 1. A sufficient quantity of dust shall be available in the chamber originally in order to give the specified dust concentration throughout the chamber. The device shall be circulated for 5 minutes and the dust shall be allowed to settle down.
JSS Revision No. JSS , knowns as the Penta-Five test, is an antifungal product test for electronics. This Joint Services Specification has. When the test is employed to demonstrate a certain degree of robustness in an equipment which is normally protected by isolators, the equipment shall, unless otherwise specified, be mounted directly to the table and the test out with the isolators removed or blocked. The sweep will be carried Hz in 15 minutes for each axis: Final measurement — The equipment shall be visually examined and shall be subjected to electricalmechanical and other checks as specified. The total duration of the simulation shall be 1. The above conditions shall be maintained for a period of 12 hours.
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