1、A. E.C. M .A. STANDARD NORME A.E.C.M.A. A.E.C.M.A. NORM Approved by COMITG DE NORMALISATION Tlie equivalent versions in French and Gernian languages can be supplied Iiy 8.N.A.E - Technopolis 54 - 199, rue Jean-Jacquei Rousseau of A.E.C.M.A. 1991-04-10 92138 ISSY LES MOULINEAUX CEDEX - FRANCE prEN 25
2、91 Part BI Edition 1 May 1991 . I EDITE PAR LASSOCIATION EUROPEENNE DES CONSTRUCTEURS DE MATERIEL AEROSPATIAL 88, boulevard Malesherbes, 75008 PARIS - TEL. 45-63-82-85 UDC : Key words : Aerospace industry, aircraft equipment, elements of electrical and optical connection, test ENGLISH VERSION Aerosp
3、ace series Test methods Elements of electrical and optica connection Part BI - Contact resistance - low level Srie arospatiale Organes de connexion lectrique et optique Mthodes dessais Partie BI - Rsistance de contact sous faible intensit Luft- und Raumfahrt Elektrische und optische Verbindungseleme
4、nte Prfverfahren Teil BI - Kontaktwiderstand im Schwachstrombereich This Aerospace series standard has been drawn up under the responsibility ofAECMA (Association Europenne des Constructeurs de Matriel Arospatial). It is published on yellow paper in three equivalent versions (English, French, German
5、). It will be submitted as a draft European Standard to CEN (European Committee for Standardization) for final vote. prEN 2591-B1 Page 3 1 This standard specifies a method for measuring the low level electrical resistance across a pair of mated contacts and their terminations. It shall be used toget
6、her with EN 2591, Scope and field of application 0 2 Reference IEC 50(302) International electrotechnical vocabulary - Chapter 302 : Electrical measuring instruments EN 2591 Aerospace series - Elements of electrical and optical connection - Test methods - General 1) 3 Preparation of the specimens 3.
7、1 They shall be fitted with their wired contacts and mated. The contacts concerned shall not have been subjected to any prior fatigue tests or heating at rated current, O 3.2 Unless indicated in the technical specification or EN 2591, the following details shall be specified : - Measuring points - T
8、ype of cable - Test temperature - Permissible limits of contact resistance 4 Apparatus The measuring instruments shall be of accuracy class 1,5 for current and 0,5 for voltage (see IEC 50(302), A schematic diagram of the test apparatus is shown in figure 1 : OAtolA n Variable d.c. power source OAtol
9、A or battery and rheostat Microvoltmeter 1 specimen(s) Figure 1 1) Published as AECMA standard at the date of publication of the present standard. _ _ - -. O Previous page is blank 7 ICEN *PREN*Z591 91 3404589 0013b42 T W prEN 2591-B1 Page 4 I = Test direct current Ml = d.c. ammeter (optional) for a
10、djusting current to 1 A when the measuring R1 = 0,02011-resistor, The use of an ammeter shunt providing a 20 mV potential circuit is open. drop at terminals under 1 A is suggested. R2 = 0,20Lmin. resictor, This resistor may be used for limiting and measuring current, It may be replaced by a d.c. cen
11、tre zero, 100 mA full scale, 1 2 precision milliammeter. if this apparatus has a shunt resistance below 0,2& , add an additional resistor to reach a total of min. 0,24. SI = Reversing switch, central position, open. To prevent rupturing of the insulating films on the contacts, the measuring circuit
12、e,m.f, in open circuit, shall not exceed 20 mV d.c. The test current shall not exceed 10 mA d,c. 5 Method .L 5.1 Measurements shall be carried out with d.c. current in both directions. 5.2 Number of contacts to be measured per size Number of contacts of the same Minimum percentage size in an element
13、 of connection N to be measured : 2 N 5 100 5NZ 60 50 1) 60 N 130 25 1) N 7 130 10 i) 1) The result shall be, if necessary, raised to the next full number. 5.3 Procedure The contact resistance shall be measured as shown in figure 2: Connector -r - -7 Figure 2 ,A CEN *PRENEZ531 31 3404583 0013b43 L i
14、 prEN 2591-B1 Page 5 The specimen shall not be unmated while the measuring voltage is applied. During the measurements, care shall be taken to avoid movement of the test cables in order to eliminate stresses on the contacts, The resistance of the cable or wire used shall be subtracted from the measu
15、red value. The corrected value shall be recorded, The measurement shall be made three times in each direction of current. The value retained is the average of the three cycles (i.e. six measurements), 5.4 Requirement , The mean value and the value of each measurement shall not exceed the specified value,
