1、AECMA STANDARD NORME AECMA AECMA NORM Edition approved for publication prEN 2004-7 Edition P 1 February 1996 C5 Chairman Comments should be sent within six months after the date of publication to PUBLISHED BY THE EUROPEAN ASSOCIATION OF AEROSPACE INDUSTRIES (AECMA) Gulledelle 94 - 8-1 200 BRUXELLES
2、- Tel. (32) 2 775 81 10 - Fax. (32) 2 775 81 11 ICs : Descriptors ENGLISH VERSION Aerospace series Test methods for aluminium and aluminium alloy products Part 7 : Reference blocks for the calibration of measuring equipment used in the determination of electrical conductivity of wrought aluminium an
3、d aluminium alloys Srie arospatiale Mthodes dessais applicables aux produits en aluminium et alliages daluminium Partie 7 : Blocs de rfrence pour ltalonnage pour la dtermination de la conductivit lectrique daluminium et dalliages daluminium corroys Luft- und Raumfahrt Prfverfahren fr Erzeugnisse aus
4、 Aluminium und Aluminiumlegierungen Teil 7 : Referenzblcke zur Eichung von Megerten zur Bestimmung der elektrischen Leitfhigkeit von gekneteten Aluminium und Aluminium-Legierungen This “Aerospace Series“ Prestandard has been drawn up under the responsibility of AECMA (The European Association of Aer
5、ospace Industries). it is published on green paper for the needs of AECMA-Members. It has been technically approved by the experts of the concerned Technical Committee following comment by the Member countries. Subsequent to the publication of this Prestandard, the technical content shall not be cha
6、nged to an extent that interchangeability is affected, physically or functionally, without re-identification of the standard. After examination and signature of the AECMA Standard Checking Centre NPS) and formal agreement of the Officiai Services of the Member countries it will be submitted as a dra
7、ft European Standard to CEN (European Committee for Standardization) for formal vote. 1996-02-29 AECMA Gulledelle 94 B-1200 BRUXELLES Mr Odorico Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networki
8、ng permitted without license from IHS-,-,-AECMA PREN*2804-7 96 W 1012311 0010685 463 W Page 2 EN 2004-7 : 1996 Contents list 1 Scope . 2 Normative references 3 Definitions . 4 Production and calibration of master reference standards . 5 Production and calibration of secondary reference blocks . 6 Pr
9、oduction and calibration of operating reference blocks 7 Calibration schedule 8 Identification 9 Records . 10 Availability . 11 Disputes Annex A (informative) Page 3 3 3 4 4 5 6 6 7 7 7 8 Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AEC
10、MANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AECMA PREN*2004-7 96 W LOL23LL OOLOb8b 3TT Page 3 EN 2004-7 : 1996 1 Scope This standard defines different types of electrical conductivity reference blocks, to be used for the calibration of eddy current conductivi
11、ty measuring equipment, their method of production and Cali bration. It is to be used in conjunction with EN 2004-1. 2 Normative references This European Standard incorporates by dated or undated reference provisions from other publications. These normative references are cited at the appropriate pl
12、aces in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication ref
13、erred to applies. IS0 1 O01 2-1 Quality assurance requirements for measuring equipment - Part 1 : Metrological confirmation system for measuring equipment EN 2004-1 Aerospace series - Test methods for aluminium and aluminium alloy products - Part 1 Determination of electrical conductivity of wrought
14、 aluminium alloys 3 Definitions For the purposes of this standard the following definitions apply : 3.1 Master reference standards A set of electrical conductivity reference standards, held by a National Standards Laboratory or an Accredited Laboratory and traceable to electrical reference standards
15、. This set is maintained as the reference standard against which all the corresponding secondary reference blocks shall be calibrated. 3.2 Secondary reference blocks Sets of electrical conductivity reference blocks calibrated by a National Standards Laboratory or an Accredited Laboratory against its
16、 master reference standards using eddy current conductivity measuring equipment. Individual companies or organisations may hold sets of secondary reference blocks. These blocks are the means by which traceability to the master reference standards is maintained. 3.3 Operating reference blocks Sets of
17、 electrical conductivity reference blocks prepared and calibrated by competent personnel against secondary reference blocks using eddy current conductivity measuring equipment. The operating reference blocks are used for routine instrument calibration. Copyright Association Europeene des Constructeu
18、rs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AECMA PREN+2004-7 96 m LOL23LL ROLOb7 236 m Page 4 EN 2004-7 : 1996 4 Production and calibration of master reference standards 4.1 The master referenc
19、e standards shall be taken from wrought material of an appropriate electrical conductivity, in a stable metallurgical condition and whose electrical conductivity homogeneity at the surface and through the thickness has been verified (see 4.3). The surface roughness shall not exceed a value of Ra = 1
20、,6 pm. 4.2 Calibration shall be carried out at a temperature of 20 OC f 2 OC, using a method which ensures traceability to electrical standards. The result shall be normalized to a temperature of 20,oo OC. 4.3 All appropriate precautions shall be taken to ensure that variations of electrical conduct
21、ivity (measured by an eddy current method) at the surface of any standard do not exceed 0,05 MS/m, and that variations associated with a frequency change over a range of 1 O kHz to 1 O0 kHz do not exceed 0,05 MS/m. 5 Production and calibration of secondary reference blocks 5.1 The secondary referenc
22、e blocks shall be taken from wrought material of an appropriate electrical conductivity, in a stable metallurgical condition and whose homogeneity at the surface and through the thickness has been verified. They shall preferably be taken from the same material as that used to produce the master refe
23、rence standards. The surface roughness shall not exceed a value of Ra = 1,6 pm. 5.2 The secondary reference blocks shall consist of square or circular samples with a thickness of at least 4 mm and sides or diameter of at least 30 mm. However, the dimensions shall be large enough compared with the pr
24、obe area in order to avoid edge effects. 5.3 The secondary reference blocks shall be calibrated against master reference standards using properly calibrated eddy current conductivity measuring equipment. The calibration shall be performed at 20 OC f 2 OC using the normalized conductivity value of th
25、e master reference standards for comparison. The values shall be normalised to a temperature of 20,OO OC. The secondary reference blocks shall be calibrated at a frequency, within the calibrated range of the master reference standards, as required by the purchaser of these blocks (usually 60 kHz). 5
26、.4 The secondary reference blocks shall be available as a set of at least four blocks of electrical conductivity values covering the whole range required for the calibration of operating reference blocks. Additional blocks may be required to ensure a finer coverage of some frequently used ranges. 5.
27、5 When the secondary reference blocks are anodised for protection (anodised layer between 10 pm and 15 pm on aluminium alloy blocks) the corresponding lift-off effect shall be taken into account and appropriate means devised to compensate for it when calibrating against the master reference standard
28、s. 5.6 The secondary reference blocks shall be supplied together with a certificate of measurement issued by a National Standards Laboratory or an Accredited Laboratory stating the electrical conductivity values registered in MS/m, the test frequency used and the temperature at which the values have
29、 been normalized. The maximum overall uncertainty (at 95 % confidence limit) of the stated electrical conductivity values shall not exceed f 0,7 %. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or netwo
30、rking permitted without license from IHS-,-,-AECMA PREN*Z04-7 96 LOLZ3LL OOLObBB 172 Page 5 EN 2004-7 : 1996 6 Production and calibration of operating reference blocks 6.1 To avoid undue wear on secondary reference blocks, it is recommended that sets of operating reference blocks be used for the rou
31、tine calibration of conductivity measuring equipments. The surface roughness shall not exceed a value of Ra = 1,6 pm. 6.2 The operating reference blocks shall normally be taken from wrought material of an appropriate electrical conductivity, in a stable metallurgical condition and whose uniformity o
32、f electrical conductivity over the surface has been verified. The material chosen shall exhibit no permanent change in electrical conductivity values as a result of storage or operating conditions. They shall be of such shape, size and finish that inaccuracies due to edge-effect and lift-off are avo
33、ided with the particular instrument to be calibrated. Their thickness shall be appropriate for the intended test frequency (see EN 2004-1). 6.3 The calibration of operating reference blocks shall be carried out by comparison against a set of secondary reference blocks. The calibration shall be carri
34、ed out at the same frequency as that intended for routine testing (usually at a frequency of 60 kHz). 6.4 The calibration of the operating reference blocks shall be carried out using the following method : - measurements shall be carried in a temperature-controlled environment at 20 OC I 2 OC; the a
35、ctual temperature variation during this calibration shall be within k 0,5 OC. - an eddy current, comparison type conductivity meter operating at the required frequency shall be used (see 6.31, - sufficient time shall be allowed for the operating and secondary reference blocks, the eddy current condu
36、ctivity meter and the probe to reach ambient temperature (unnecessary handling of the blocks shall be avoided), - using the eddy current electrical conductivity meter, record the indicated values for a set of secondary reference blocks. The meter reading shall indicate the certified value k 0,2 MS/m
37、 or k 0,3 % IACS (International Annealed Copper Standard). If this is not the case then the eddy current electrical conductivity meter shall not be used for calibration of operating reference blocks 1). 1) Non linear interpolation techniques may be used to compensate for a non linear response of the
38、 instrument. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,- - - AECMA PRENu2004-7 96 = 3032333 0030689 O09 Page 6 EN 2004-7 : 1996 - read and record
39、the conductivity of each applicable operating reference block. Conductivity readings shall be considered valid if they fall within a range of f 2 MS/m or I3,5 % IACS from the electrical conductivity of the applicable secondary reference block. When electrical conductivity readings fall outside the r
40、ange of f 2 MS/m or k 3,5 % IACS then the electrical conductivity values to be used shall be determined by linear interpolation .e. using the formula : Co = Cl + c2 - (So-S1) s2 - SI where : CO is the calibrated conductivity of the operating reference block ; CI is the calibrated conductivity of the
41、 next lower secondary reference block ; C2 is the calibrated conductivity of the next higher secondary reference block ; SO is the electrical conductivity meter scale reading for the operating reference block (mean value of five measurements) ; SI is the electrical conductivity meter scale reading f
42、or the next lower secondary reference block (mean value of five measurements) ; S2 is the electrical conductivity meter scale reading for the next higher secondary reference block (mean value of five measurements). 6.5 method according to IS0 10012-1. The uncertainity of the reference block calibrat
43、ion shall be evaluated using an appropriate 7 Calibration schedule 7.1 Secondary reference blocks shall be calibrated at intervals not exceeding four years. The interval shall be shorter if there is any reason for it (see 7.3). The National Standards Laboratory or the Accredited Laboratory shall pro
44、vide a calibration service for secondary reference blocks. 7.2 method defined in 6.4. Operating reference blocks shall be calibrated at intervals not exceeding 13 months by the 7.3 is suspect for any reason shall be re-calibrated before further use. Any reference block which has been exposed to exce
45、ssive heat, mechanical damage, wear or 8 Identification All reference blocks shall be identified with a unique indelible identification number or mark. Conductivity values and next calibration date shall be indicated on the sets. Copyright Association Europeene des Constructeurs de Materiel Aerospat
46、ial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AECMA PREN*2004-7 96 = 10L23LL OOLOb90 820 Page 7 EN 2004-7 1996 9 Records Calibration records shall be kept for each reference block in accordance with appropriate Quality
47、Procedures, and shall include the following : identification of reference block, nominal conductivity value, uncertainity on this conductivity value, type of block (e.g. secondary) date of Calibration, identification of apparatus and reference blocks used during calibration, temperature of calibrati
48、on, frequency of calibration, results normalized calibration values (where appropriate). 1 O Availability The list of Accredited Laboratories from which sets of secondary reference blocks may be purchased is given in annex A. 11 Ois putes Should any dispute arise as to the conductivity of any refere
49、nce block, the disputed block should initially be compared with another appropriate secondary reference block. Should the dispute not be resolved in this way, a National Standards Laboratory or an Accredited Laboratory shall be agreed by all parties to compare the disputed secondary reference block with a master reference set. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot fo
