1、 STD-BSI BS EN 2591-30b-ENGL 1998 3624bb9 0735087 BRITISH STANDARD AEROSPACE SERIES Elements of electrical and optical connection - Test methods - Part 306: Mould growth 44b BS EN 259 1-306: 1998 The European Standard EN 2591306 1998 has the status of a British Standard ICs 49.060 BS EN 2591306:1998
2、 This British Standard, having been prepared under the direction of the Engineering Sector Board, was published under the authority of the Standards Board and comes into effect on 15 August 1998 National foreword This British Standard is the English language version of EN 2591306 1998. The UK partic
3、ipation in its preparation was entmsted by Technical Committee ACEYG, Aerospace avionic, electrical and fibre optic technology, to Subcommittee ACW6/3, Aerospace - Connectors, which has the responsibility to: - aid enquirem to understand the text; - present to the responsible internationaUEuropean c
4、ommittee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; - monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cr
5、oss-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Stan - method to be used (A or B); - period of exposure; - extent of acceptable mould growth;
6、 - preliminary cleaning (if applicable); - initial measurements (if applicable); - final measurements and requirements (if applicable). Page 4 EN 2591 -306: 1998 4 Test preparation 4.1 Mould cultures The following cultures (table 1) shall be used to carry out the test. The nature of the attack to be
7、 expected from each culture is indicated, but all strains shall be used together, whatever the nature of the specimen. Table 1 - Cultures gumber 1 2 3 4 5 6 7 8 - Name Aspergillus niger Aspergillus terreus Aureobasidium pullulans Paecilomyces varioti Penicillium funiculosum Penicillium ochro-chloron
8、 Scopulariopsis brevicaulis Trichoderma viride Strain V. Tieghem Thom. (De Barry) Arnaud Bainier Thom. Biourge (Sacc.) Bain Var. Glabra Thom Pers. ex Fr. Typical culture for guidance only) ATCC.6275 PQMD.82j ATCC.9348 IAM. 5001 IAM. 7013 ATCC. 91 12 IAM. 5146 IAM. 5061 Nature Grows profusely on many
9、 materials and is resistant to copper salts Attacks plastic materials Attacks paints and varnishes Attacks plastics and leather Attacks many materials especially textiles Resistant to copper salts and attacks plastics and textiles Attacks rubber Attacks cellulose textiles and plastics Cultures shall
10、 be obtained from an approved mycological institute which shall certify that they are suitable for the test. 4.1.1 plugs, or as otherwise considered appropriate by the mycological institute. The cultures shall be supplied as spores, on an agar medium, in glass containers with cotton 4.1.2 The cultur
11、es used for preparing the test suspension shall be preferably between 14 d and 21 d old. In no case shall cultures which are less than 14 d or more than 28 d old be used. The stoppers shall not be removed until the suspension is about to be made, and only one suspension shall be made from the opened
12、 container. A fresh, unopened container shall be used for each preparation of a suspension. The cultures shall be stored in a refrigerator at a temperature between 5 OC and 1 O OC. 4.2 Preparation of spore suspension 4.2.1 non-fungicidal wetting agent. An agent based on N-methyl or on dioctyl sodium
13、 sulphosuccinate may be accepted. The suspension shall be prepared in deionized water to which has been added 0,05 % of a Page 5 EN 2591-306:1998 4.2.2 A platinum or a nichrorne wire shall be sterilized by heating to red heat in a flame and allowed to cool. This wire shall then be used to scrape gen
14、tly the surface of the culture to liberate spores. The liquid shall be slightly agitated to disperse the spores without detaching mycelial fragments. The suspension shall then be decanted into a flask. 10 ml of the water with wetting agent shall be poured gently into each tube. 4.2.3 break up any cl
15、umps of spores. All eight suspensions shall be shaken vigorously together in a flask to mix thoroughly and to 4.2.4 The suspension shall be used on the day of its preparation, and shall not be stored for future use. 4.3 It shall consist of a solution of the following materials in distilled water. Th
16、e quantities are amounts per litre of water. Preparation of the nutrient solution Modified Czapek-Dox nutrient solution with saccharose Potassium dihydrogen orthophosphate (KH2POJ 0,7 g Potassium monohydrogen orthophosphate (K2HPOJ 03 g Sodium nitrate (NaNO,) Potassium chloride (KCP) Ferrous sulphat
17、e (FeS047H,0) Saccharose 30 The solution shall be sterilized in an autoclave at 115 OC for 30 min. The pH solution shall then be measured and adjusted, if necessary, by addition of a 0.01 N sodium hydroxide solution to obtain a pH between 6,O and 6,5 after sterilization. 4.4 Control strips They shal
18、l be made of white filter paper which has not been exposed to any fungicidal treatment. They shall be placed in glass dishes and covered with the nutrient soiution (see 4.3). They shall be removed from this solution and allowed to drain immediately before use. The strips shall be prepared on the day
19、 the test commences. A freshly prepared nutrient solution shall be used for preparing each group of control strips. These strips shall be sprayed with the same suspension as that used for the specimens, Page 6 EN 2591 -306: 1998 5 Method These tests shall only be carried out by approved laboratories
20、. All specimens, reference specimens and a group of three control strips shall be put in separate containers. All containers shall be placed together in the same test chamber. The specimens and control strips shall be placed in the chamber within 15 min after spraying with spores. They shall not be
21、unduly disturbed during the test, except for opening container lids and the chamber door each week. The test chamber used shall maintain a temperature between 28 OC and 30 OC. Any periodic variation in temperature due to action of the thermostat shall not exceed 1 OC/h. Each specimen and control str
22、ip shall be put in a glass or plastic container (e.g. a Petri dish) with a lid. The container shall permanently contain water to maintain a relative humidity greater than 90 % inside. The specimens shall not be immersed or splashed by the water. The container lid shall be removed for a few seconds o
23、nce per week to ensure a regular supply of oxygen in the air to the growing moulds. The first opening shall be 7 d after spraying. If no mould growth is visible on any control strip, the test shall be considered invalid and shall be repeated. 5.1 Initial measurements (if applicable) They shall be ca
24、rried out as specified. If mould growth on the control strips indicates that the conditions are suitable and the moulds viable, the test shall continue for the time specified. If the chamber, or a container, becomes contaminated and must be cleaned, the preferred method is to heat it in a moisture s
25、aturated atmosphere at 120 OC for 1 h. Where heating is not possible, dry the chamber or the container and fumigate it with propylene oxide, finally washing it with water containing a detergent and ventilating it well to remove all oxide fumes. 5.2 Procedure 5.2.1 Method A Expose the specimens to th
26、e suspensions which shall be supplied with a medium containing no assimilable carbon. Mould growth can only take place to the detriment of the specimen component materials. If there are no edible materials, spores can not develop and there will be no attack. The period of exposure shall be one of th
27、e following: - 28 d: assessment of the mould growth by a single visual examination; - 84 d: in addition to assessment of the mould growth, assessment of the damage due to mould growth by the specified measurements. If 84 d exposure is specified, two groups of specimens shall be required: - first gro
28、up: specimens; - second group: reference specimens for damp heat test. The temperature and relative humidity conditions shall be identical for both tests, (mould growth and damp heat). STD-BSI BS EN 2593-30b-ENGL 1998 1624bb9 0735095 532 Page 7 EN 2591-3061998 5.2.1.1 Sprayings Sprayings shall be do
29、ne with pipettes or spray guns depending on the nature of the spray, but with identical characteristics. The nozzle, in particular, shall be large enough not to be blocked by fragments of mycelium. 5.2.1.2 Specimens (28 d or 84 d) They shall be sprayed with the suspension according to 4. 5.2.2 Metho
30、d B Expose the specimens to the specified suspensions deposited on a nutrient medium allowing mould to grow previously applied to them. Even if the specimens do not have any nutrient elements, mould growth may progress as well as the action of the products of their metabolism. The period of exposure
31、 (28 d or 84 d) shall be specified. Regardless of the period of exposure, mould growth shall be assessed by visual examination and the damage to specimens by measurements. Three groups of specimens are required: - first group: specimens; - second group: reference specimens for damp heat test; - thir
32、d group: laboratory reference specimens which shall not be exposed to any test and to be used as reference for visual examination. The periods of exposure, the temperature and relative humidity conditions for the first group exposed to the mould growth test and the second group exposed to the damp h
33、eat test shall be identical. 5.2.2.1 Sprayings See 5.2.1.1. 5.2.2.2 Specimens They shall be sprayed with a sufficient quantity of nutrient solution (see 4.3) and allowed to dry. After drying, specimens shall be sprayed with the suspension (according to 4) on all their exposed surfaces. 5.2.2.3 Refer
34、ence specimens for damp heat test They shall be sprayed with an amount of sterile water containing a wetting agent equal to the amount of nutrient solution with suspension which has been sprayed on the specimens. 5.2.2.4 Control strips See 4.4. They shall be sprayed with a sufficient amount of nutri
35、ent solution and then allowed to dry. After drying, strips shall be sprayed with the same suspension as that sprayed on the specimens. The strips shall be tested at the same time and in the same test chamber as the specimens. STD-BSI BS EN 2591-30b-ENGL 3778 Lb24bb9 073507b 459 Page 8 EN 2591 -306 9
36、98 5.3 At the end of the test, specimens shall be subjected to a visual examination for assessment of mould growth. It shall be expressed according to the following scale: Measurements and requirements (Methods A and BI - O: - 1 : - 2: - 3: no growth apparent under a magnification of 50 times; mould
37、 growth not visible to the naked eye, but apparent under a magnification of 50 times; growth visible to the naked eye, but covering less than 25 % of the surface; growth visible to the naked eye and covering more than 25 % of the test surface. The myceliae shall then be carefully washed from the sur
38、face of the specimens, and the surface shall be examined through a magnifying glass or microscope to assess the nature of any physical attack or etching on the specimens. 5.4 Recovery Following the visual examination (according to 5.3) and where measurements after recovery are specified, the specime
39、ns shall be allowed to recover to initial conditions for 24 h. 5.5 Final measurements and requirements (Method B only) (if applicable) - EN 2591-206 - EN 2591-207 - EN 2591-101 These tests shall be carried out on specimens and on reference specimens. Any substantial variation between the results of
40、the two series of measurements shall be considered as due to mould growth. BS EN 2591-306:1998 BSI 389 Chiswick High Road London w4 4AL BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on stanards in Europe
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