1、i- CEN PREN*25I (PART*CB) 72 - 3404589 0026974 I - A. E.C. M .A. STAN DARD NORME A.E.C.M.A. A.E.C.M.A. NORM prEN 2591 Patt C8 Issue P 1 June 1992 DIT FAR LASSOCIATION EUROPENNE DES CONSTRUCTEURS DE MATRIEL AROSPATIAL Technopolis - 175, rue Jean-Jacques Rousseau - F-92138 Issy-les-Moulineaux Cdex -Tl
2、. (1) 47.36.98.76 UDC : Key words : ENGLISH VERSION Aerospace series Elements of electrical and optical connection Test methods Part C8 - Sand and dust Srie arospatiale Luft- und Raumfahrt Mthodes dessais Prfverfa hren Organes de connexion lectrique et optique Partie C8 - Sable et poussires Elektris
3、che und optische Verbindungselemente Teil C8 - Sand und Staub This .Aerospace Series pre-standard has been drawn up under the responsibility of AECMA (Association Europenne des Constructeurs de Matriel Arospatial). It is published on green paper for the needs of AECMA-Members. It has been technicall
4、y approved by the experts of the concerned Commission following comment by the Member countries. Subsequent to the publication of this pre-standard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of t
5、he standard. After examination and signature of the AECMA Standard Checking Centre (NPS) and formal agreement of the Official Services of the Member countries it will be submitted as a draft European Standard to CEN (European Committee for Standardization) for final vote. Nota - Extra copies can he
6、supplied by B.N.A.E. - Technopolis 54 - 199, rue Jean-Jacques Rousseau - 921 38 ISSY-LES-MOULINEAUX CEDEX Edition approved for publication 1992-06-05 Comments should be sent within six months after the date of publication decision A.E.C.M.A. Technopolis - 175, rue Jean-Jacques Rousseau 921 38 Issy-l
7、es-Moulineaux Cdex - FRANCE C2 Chairman M. J. LE CUNFF 0 aecrna 1992 g CEN PREN*2591 (PART*CB) 92 W 3404589 002b975 3 prEN 2591-C8 Page 3 1 Scope and field of application This standard specifies a method of assessing the ability of an element of connection to withstand driving fine sand and dust. It
8、 shall be used together with EN 259 1. 2 References EN 2591 Aerospace series - Elements of electrical and optical connection - Test methods - General EN 2591-D8 Aerospace series - Elements of electrical and optical connection - Test methods - Part D8 - Mating and unmating forces 1) 3 Preparation of
9、specimens 3.1 The specimens shall be fitted with their normal accessories mounted and wired according to the technical specification. When required by the technical specification, the specimens shal be mated and unmated as many times as specified prior to the test. The test shall be carried out on m
10、ated or unmated specimens with protective cover. 3.2 Unless indicated in the technical specification, the following details shall be specified : - method of mounting and definition of specimen wiring, - number of positions and specimen orientation, - requirements for the injtial and final measuremen
11、ts, - air speed (in jet), - number of cycles. 4 Apparatus The test chamber length, section and configuration shall be so designed as to : - avoid turbulent flows ahead of the test specimen and limit them as much as possible behind it, - favour uniform distribution of solid particles within the airst
12、ream. 1) Published as AECMA pre-standard at the date of publication of the present standard. Previous page is blank t CEN PREN*2591 (PART*C8) 92 W 3404589 0026976 5 prEN 259 1 -C8 Page 4 The climatic test chamber shall be provided with control devices for monitoring the following parameters within s
13、pecified limits throughout the test : - jet density (opacity-measuring photoelectrical cell systems are recommended) ; - airflow speed, - relative humidity and temperature around the specimen. The sand and dust used for the test shall be abrasives with the following characteristics : - 100 YO shall
14、pass through a 150 ym mesh sieve, - 98 “/o shall pass through a 100 ,um mesh sieve, - 90 YO shall pass through a 75 pm mesh sieve, - 75 % shall pass through a 45 ym mesh sieve, - the particles shall contain between 97 %.and 99 % Si02. 5 Method 5.1 Initial measurements (if applicable) They shall be m
15、ade as specified by the detail specification. The specimen shall be submitted to the following test : mating and unmating forces (test EN 2591-D8). 5.2 Positions of the specimen in the test chamber The number of positions and the orientation of specimen with respect to the airflow shall be as specif
16、ied by the technical specification. 5.3 Procedure The technical specification shall define the number of cycles to be performed. Each cycle lasts 3 h and consists of four steps : a) within 30 min, the test chamber shall be stabilised within the following limits : 1) temperature : (30 f 3) OC ; 2) re
17、lative humidity : lower than 30 % ; 3) air speed : the technical specification shall define a speed between 3 m/s and 10 m/s. The recommended speed is (3,5 CEN PREN*Z59L (PARTmCB) 92 = 3404589 O026977 7 . prEN 259 1 -C8 Page 5 4) Concentration of the particles : (6 f 3) g/m3 ; b) the above condition
18、s shall be maintained for 1 h ; c) within 30 min, the temperature shall be brought to (65 f 5) OC, the other parameters remaining unchanged ; d) the new conditions shall be maintained for 1 h. Unless otherwise specified, a cycle shall be performed for each orientation. Between two successive cycles,
19、 the temperature shall be reduced to (30 & 3) OC within 2 h maximum. 5.4 Recovery Directly after the test and to prevent the effects of moisture, dust shall be removed from the mated specimen by shaking, wiping or brushing but no blower or suction devices shall be used to avoid dust ingress in the s
20、pecimen. The specimen shall be allowed to recover as long as required for it to reach room temperature. 5.-5 Final measurements and requirements (if applicable) Final measurements shall be made as specified by the technical specification. The specimen shall be subjected to test EN 2591-D8, recording the value of the first unmating.
