1、BRITISH STANDARD AEROSPACE SERIES BS 3G.100-2-3.11: 1973 Specification for General requirements for equipment for use in aircraft Part 2: All equipment Section 3: Environmental conditions Subsection 3.11: Water-proofness UDC 629.7.05/.06:620.16.4BS3G.100-2-3.11:1973 This British Standard, having bee
2、n approved by the Aerospace Industry Standards Committee, was published under the authorityof the Executive Board of the Institution on 15 October, 1973 BSI 02-1999 The following BSI references relate to work on this standard: Committee reference ACE/58 Draft for comment 71/30576 ISBN 0 580 07635 0
3、Amendments issued since publication Amd. No. Date CommentsBS3G.100-2-3.11:1973 BSI 02-1999 i Contents Page Foreword ii 1 Scope 1 2 Grades of water-proofness 1 3 Test for Grade A: spray proof equipment 1 3.1 Test conditions 1 3.2 Initial examination 1 3.3 Test procedure 1 3.4 Recovery 1 3.5 Final exa
4、mination 1 3.6 Information to be included in the relevant equipment specification 2 4 Tests for Grade B: drip proof equipment 2 4.1 Test conditions 2 4.2 Initial examination 2 4.3 General description of test 2 4.4 Description of test apparatus 2 4.5 Testing procedure 2 4.6 Recovery 2 4.7 Final exami
5、nation 2 4.8 Information to be included in the relevant equipment specification 2 Appendix A Details of shower head 4 Figure 1 Test rig for drip test 3 Figure 2 Dimensions of shower head 4BS3G.100-2-3.11:1973 ii BSI 02-1999 Foreword This British Standard is part of a composite standard in the Aerosp
6、ace series of British Standards specifying general requirements for equipment for use in aircraft. An introduction to the complete British Standard is given in BritishStandard 3G.100-0. This subsection of British Standard 3G.100 supersedes Clauses214 and 215 in British Standard 2G.100-2:1962, and de
7、tails tests for two grades of water-proofness. It reflects the technical content of a similar Draft International Standard currently under consideration by the International Organization for Standardization (ISO) Technical Committee 20. This standard makes reference to the following British Standard
8、s: BS 3G.100, General requirements for equipment in aircraft. BS 3G.100-0, Introduction. BS 2011, Methods for the environmental testing of electronic components and electronic equipment. BS 2011-2Qg, Sealing, driving rain. NOTEInformation concerning metric (SI) units is given in BS 350, “Conversion
9、factors and tables”, BS 3763, “The International System of units (SI)” and in PD5686 “The use of SI units”. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British S
10、tandard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 4 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be
11、indicated in the amendment table on theinside front cover.BS3G.100-2-3.11:1973 BSI 02-1999 1 1 Scope This British Standard specifies tests for two grades of water-proofness applicable to equipment in aircraft which is required to operate when exposed to conditions when water is sprayed on it, as in
12、driving rain, or water dripping on it, such as condensation falling from adjacent aircraft structure. It should also be read in conjunction with British Standard 3G.100-0. 2 Grades of water-proofness When required by the relevant equipment specification, the equipment shall be declared as complying
13、with either of the following grades of water-proofness: 1) Grade A: spray proof. Equipment which is subjected to driving rain or required to operate when water is sprayed on it from any angle. Typical equipment in this grade would be that which is installed in the wheel bay of an aircraft where it w
14、ould be subjected to rainwater being sprayed on it from a wet runway. Grade A equipment shall be subjected to the test described in Clause 3. Equipment which is hermetically sealed 1) may be considered as waterproof to Grade A requirements provided any electrical terminals are of a suitable design t
15、o ensure adequate insulation. 2) Grade B: drip proof. Equipment which is required to operate in conditions when moisture droplets may be expected to fall on it, particularly unsealed equipment which may be so located that condensate from neighbouring structures, particularly the aircraft frame, occu
16、ring during the descent of a cold aircraft into a humid atmosphere can fall directly upon parts of equipment critical to wetting. Grade B equipment shall be subjected to the test described in Clause 4. This test would not normally be required for equipment which complies with the requirements for Gr
17、ade A equipment. 3 Test for Grade A: spray proof equipment 3.1 Test conditions 3.1.1 The equipment shall be subjected to this test in its normal mounting attitude(s) unless specified otherwise in the relevant equipment specification. 3.1.2 All connections to the equipment shall be made as in normal
18、operation, or blanks having equivalent sealing properties shall be fitted. 3.1.3 If equipment is fitted with removable covers etc., these shall be placed in position as in normal operation. 3.1.4 During the test the equipment shall, if required by the relevant equipment specification, be operated in
19、 the manner most vulnerable to the effects of ingress of water. 3.2 Initial examination. The equipment shall be visually inspected and electrically and mechanically checked as required in the relevant equipment specification. All sealing features shall also be checked to determine whether they have
20、been mounted correctly. 3.3 Test procedure 3.3.1 The equipment shall be subjected to a shower of water from the shower head nozzle, specified in3.3.3, which shall be directed perpendicularly to the most vulnerable area(s) of the equipment, as stated in the relevant equipment specification. The area
21、or areas under test shall each be exposed to the spray for a minimum period of 15 minutes. NOTEIf desired, the test may be applied simultaneously to more than one area at a time by using an appropriate number of shower heads. 3.3.2 The shower head shall be located not more than 2.5 m from the surfac
22、e under test. 3.3.3 The dimensions of the shower head nozzle shall comply with the dimensions specified in Figure 1 of BS 2011-2 Test 2Q g. This will provide a shower with a divergent cone angle of approximately 35. For the information of readers of this standard details of this nozzle are included
23、in Appendix A. 3.3.4 The inlet pressure to the shower head nozzle shall be 2 bar (200 kPa) (30 lbf/in 2 ). NOTEThis inlet pressure corresponds to a rate of water consumption of 450 1 10% per hour. 3.4 Recovery. No recovery procedures shall be carried out at the completion of the test unless permitte
24、d and stated in the relevant equipment specification. 3.5 Final examination. The equipment shall be visually examined for penetration of water and, if required, shall be electrically and mechanically checked as prescribed by the relevant equipment specification. 1) The need for a subsection in Briti
25、sh Standard 3G.100 for sealing tests is currently under consideration. In the interim reference should be made to BS 2011 or British Standard 2G.100-2 for details of suitable sealing tests.BS3G.100-2-3.11:1973 2 BSI 02-1999 3.6 Information to be included in the relevant equipment specification. When
26、 this test is a requirement in the relevant equipment specification the following details shall be stated, as far as they are applicable: 4 Test for Grade B: drip proof equipment 4.1 Test conditions 4.1.1 The equipment shall be subjected to this test in its normal mounting attitude(s) unless specifi
27、ed otherwise in the relevant equipment specification. 4.1.2 All connections to the equipment shall be made as in normal operation, or blanks having equivalent sealing properties shall be fitted. 4.1.3 If equipment is fitted with removable covers, etc, these shall be placed in position as in normal o
28、peration. 4.1.4 During the test the equipment shall, if required by the relevant equipment specification, be operated in the manner most vulnerable to the effects of ingress of water. 4.2 Initial examination. The equipment shall be visually inspected and electrically and mechanically checked as requ
29、ired in the relevant equipment specification. 4.3 General description of test. Water is allowed to drip at a specified rate onto the equipment, from a source such that the quantity of water per unit area is controlled and constant. 4.4 Description of test apparatus. The apparatus required shall be a
30、 water container of adequate plan size having a number of orifices spaced at intervals of 25mm on a square grid in its base which permit the water to drip freely and individually, at the specified rate. The size of the container will depend upon the plan area of the equipment to be tested: it may be
31、 restricted to such dimensions as to cover selected critical areas of large equipment if permitted by the relevant equipment specification. Suitable means shall also be provided to maintain the flow and head of water for the specified time. NOTEFigure 1 gives details of apparatus currently in use fo
32、r this test. There are proposals under consideration in the international sphere for an improved type of orifice to ensure a constant drip rate. 4.5 Testing procedure 4.5.1 The equipment shall be subjected to water droplets falling vertically from the dispenser at a height of one metre. 4.5.2 Unless
33、 otherwise stated in the relevant specification the water shall be dispensed at an overall rate of not less than 350l/m 2 h for a period of not less than 15minutes. NOTEThis rate approximates to one droplet per second from each orifice. 4.6 Recovery. No recovery procedures are to be carried out at t
34、he completion of the test unless permitted and stated in the relevant equipment specification. 4.7 Final examination. The equipment shall be visually examined for penetration of water, and if required, electrically and mechanically checked as prescribed by the relevant equipment specification. 4.8 I
35、nformation to be included in the relevant specification. When this test is a requirement in the relevant equipment specification, the following details shall be stated, as far as they are applicable: Reference 1) Attitudes of the equipment, if other than normal 3.1.1 2) Operation during test 3.1.4 3
36、) lnitial visual examination, electrical and mechanical checks 3.2 4) Surfaces to be sprayed 3.3.1 5) Recovery procedures, if permitted 3.4 6) Final examination, electrical and mechanical checks 3.5 Reference 1) Attitude of equipment, if other than normal 4.1.1 2) Operation during test 4.1.4 3) Init
37、ial visual examination, electrical and mechanical checks 4.2 4) Critical areas of equipment to betested 4.4 5) Quantity of water and time, if other than as specified above 4.5.2 6) Recovery procedures, if permitted 4.6 7) Final examination, electrical and mechanical checks 4.7BS3G.100-2-3.11:1973 BS
38、I 02-1999 3 Figure 1 Test rig for drip testBS3G.100-2-3.11:1973 4 BSI 02-1999 Appendix A Details of shower head The following figure has been reproduced from BS2011-2 Test 2Qg for information. Figure 2 Dimensions of shower headblankBSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | |
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