1、BRITISH STANDARD AEROSPACE SERIES Elements of electrical and optical connection Test methods Part 601 : Optical elements - Insertion loss The European Standard EN 2591-601:2001 has the status of a British Standard ICs 49.060 BS EN 2591-601 12001 Wk present to the responsible European committee any e
2、nquiries 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 oss-r e fer e
3、nc e s 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 Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Cata
4、logue. 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 Standard does not of itself confer immunity from legal obligations. Summary of pages This document com
5、prises a front cover, an inside front cover, the EN title page, pages 2 to 8, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. O BSI 14 December 2001 ISBN O 580 38072 6 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE N
6、ORM EN 2591-601 November 2001 ICs 49.060 English version Aerospace series - Elements of electrical and optical connection - Test methods - Part 601 : Optical elements - Insertion loss Srie arospatiale - Organes de connexion lectrique et optique - Mthodes dessais - Partie 601: Organes optiques - Pert
7、es dinsertion Luft- und Raumfahrt - Elektrische und optische Verbindungselemente - Prfverfahren - Teil 601: Optische Elemente - Einfgungsdmpfung This European Standard was approved by CEN on 4 June 2001 CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the cond
8、itions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member. This European Standard exists in three o
9、fficial versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria,
10、 Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION EUROPISCHES KOMITEE FR NORMUNG COMIT EUROPEN DE NORMALISATION Management Cent
11、re: rue de Stassart, 36 B-1050 Brussels O 2001 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 2591-601:2001 E EN 2591-601 :2001 (E) Foreword This European Standard has been prepared by the European Association of Aerospace Manufac
12、turers (AECMA) . After inquiries and votes carried out in accordance with the rules of this Association, this Standard has received the approval of the National Associations and the Official Services of the member countries of AECMA, prior to its presentation to CEN. This European Standard shall be
13、given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2002, and conflicting national standards shall be withdrawn at the latest by May 2002. According to the CENKENELEC Internal Regulations, the national standards organizations of
14、 the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. 2 EN 2591-601 :2001 (E) 1 Scope
15、This standard specifies methods of measuring the insertion loss of optical connection elements (including permanent connections) and fibre optic couplers. These methods are suitable for single and multi-channel devices and hybrid configurations. It shall be used together with EN 2591-100. 2 Normativ
16、e references This European Standard incorporates by dated or undated reference provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any
17、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 referred to applies. EN 2591-100 Aerospace series - Elements of electrical and optical connection - Test methods - Part 100: Gener
18、al 1) 3 Preparation of specimens 3.1 Specimens shall be prepared as defined in the product standard and for each method of test: - the fibre ends shall comply with requirements of EN 2591-100 (Fibre end preparation and termination cleaning); - the fibre ends shall be fixed to the light launch and de
19、tector systems as defined in EN 2591-100; - the fibrekable used for the test shall meet the requirements of the optical connection element, coupler or splice product standard; - movement of the fibreskables and temporary joints shall be minimized during the test set-up and testing process; the minim
20、um bend radius of the fibrekable shall not be exceeded; the fibre lengths shall be as stated unless otherwise defined in subsequent test requirements. Unless otherwise indicated in the technical specification, the following details shall be specified: method; number of measurements to be averaged; p
21、reconditioning requirements; recovery procedure; number of channels to be tested in a multi-channel device; maximum value of insertion loss; maximum permissible standard deviation of insertion loss; launch conditions. 1) Published as AECMA Prestandard at the date of publication of this standard 3 EN
22、 2591-601 :2001 (E) 4 Apparatus It shall comprise: - a Light Launch System (LLS) as defined in EN 2591-100; - a Light Detector System (LDS) as defined in EN 2591-100. In addition, the following apparatus shall be required depending upon the method used: a) temporary joints (tj) 1) the joints shall h
23、ave a low insertion loss, good performance repeatability and have minimum reflection 2) the mean insertion loss and standard deviation of the joints shall be specified in the product standard. 3) the standard deviation of any temporary joint shall be one order of magnitude better than that stated in
24、 loss. Index matching material may be used. the product standard for the device under test. b) reference specimen 1) the dimensions and parameters shall be specified in the product standard. 2) the mean insertion loss shall be specified in the product standard. 3) the standard deviation of the inser
25、tion loss shall be specified in the product standard. 5 Methods A number of methods may be used to measure insertion loss. However, the principle is basically the same for each method. First, the amount of useful optical power which can be transmitted through the cable shall be measured without the
26、specimens installed. Then, the specimen shall be inserted into the cable and the amount of useful power shall be measured again. The insertion loss shall be defined as the decrease in the amount of transmitted optical power and shall be expressed as a ratio in decibels (dB). The launch conditions sh
27、all be defined in EN 2591-100. 5.1 Method 1 It shall be limited to a single measurement. It shall involve making the initial power measurement in a continuous (unbroken and without temporary joints) fibre. The fibre shall then be broken, the specimen inserted and the power measured again. This metho
28、d requires a new length of fibre as well as the preparation and interfacing of the fibre to the LLS and LDS for each specimen measured. a) Initial measurement Set-up, see figure 1 L = (2 f 0,l) m b) Measure power Po. Figure 1 4 EN 2591-601 :2001 (E) c) Cut fibre length L into two equal sections. The
29、 preparation of fibre ends shall comply with EN 2591. Install the specimen as shown in figure 2. 1 Key 1 Specimen Figure 2 d) Measure power Pi. e) Calculate the insertion loss using the following equation Pi Insertion loss (dB) = - 10 log - Po 5.2 Method 2 This method shall apply to pig-tailed arran
30、gements. It shall use two temporary joints. NOTE value of insertion loss may be measured. The results will depend on the quality of the two joints and fibres. In some situations, a negative a) Initial measurement Set-up, see figure 3. LI and L3 shall not exceed 5 m L2 = (2 f 0,l) m Figure 3 b) Measu
31、re power Po. c) Remove fibre L2 and replace it with the pig-tailed specimen as shown in figure 4. 1 ILLSI _ tj _ 0 _ tj _ m +-LI-+ +-L3-+ pi Key 1 Specimen Figure 4 d) Measure power Pi. e) Calculate the specimen insertion loss using the following equation Pi Insertion loss (dB) = - 10 log - Po NOTE
32、be zero. Half of the temporary joint can be an optical face on the LLS or LDS, which means LI and L3 can 5 EN 2591-601:2001 (E) 5.3 Method 3 This method is intended to minimize the ambiguities created by fibre parameter mismatches. It shall be limited to measuring pig-tailed arrangements and involve
33、 the use of temporary joints. Although it incorporates a temporary joint, the measurement shall not be dependent on the reproducibility of the joint. Initial measurement Set-up, see figure 5. 1 (LLs( _ tj _ 0 _ (LDS( pi +-LI-+ +-L2-+ +-L3-+ Key 1 Specimen L2 = L3 = (1 f 0,l) m L155m Figure 5 Measure
34、 power Pi. Cut the fibre between the temporary joint and the specimen at location L1 as shown in figure 6. 1 2 JLLsJ _ tj _ _- 0 _- +-LI -+ +-LI1 -+ Key 1 cut 2 Specimen L1 = (0,5 f 0,l) m Remove the specimen and its attached fibres from the test circuit. Prepare the fibre end of L1 as defined in EN
35、 2591-100. Couple it to the LDS as shown in figure 7 Figure 6 (LLs( _ tj _ Po +-LI-+ +-_L1_- + Figure 7 Measure power Po. Calculate the specimen insertion loss using the following equation D; ri Insertion loss (dB) = - 10 log - Po 5.4 Method 4 This method shall apply to specimens with integral cable
36、 terminations (patch cord) and uses a reference specimen. a) Initial measurement Set-up, see figure 8. 1 +-LI - + Key 1 Reference specimen LI = L2 = (1 f 0,l) m Figure 8 6 EN 2591-601 :2001 (E) b) Measure power Po. c) Disconnect the reference specimen and insert the test specimen as shown in figure
37、9. 1 +-L3-+ ILLSI _ Ra _ Rb _ m pi o o Key 1 Specimen L352m Figure 9 d) Measure power Pi. e) Calculate the insertion loss using the following equation Pi Insertion loss (dB) = - 10 log - Po 5.5 Method 5 This method shall be limited to evaluating a connector set adaptor. It shall involve the use of t
38、wo Reference connector Plugs RP and Reference Adaptor RA of known performance. a) Initial measurement Set-up, see figure 10. 1 LI=L255m Figure 10 b) Measure power Po. G) Remove RA and replace it with the Adaptor A to be measured as shown in figure 11. 1 1 Adaptator Figure 11 d) Measure power Pi. e)
39、Calculate the insertion loss of A using the following equation Pi Insertion loss (dB) = - 10 log - Po NOTE compared to that associated with the reference adaptor, in power level (Po). In this method, the resultant value shall be the additional loss that the adaptor under test produces, This method m
40、ay yield loss values that are negative (apparent gain for the adaptor) and care shall be used in interpreting the results. 7 EN 2591-601 :2001 (E) 5.6 Statistical assessment of insertion loss - Connectors A more valid assessment of the performance can be achieved by calculating the mean and standard
41、 deviation of a number of measurements. The number of measurements and the method for remating the connector when making multiple measurements depends on the nature of the particular connector family and arrangement. The following procedure for remating shall be followed: a) the connector set shall
42、be completely uncoupled and recoupled for each measurement; b) non-keyed connector sets shall be relatively rotated 120“ between components and multiple measurements made at each location; c) single keyed connectors shall have multiple measurements made at the keyed position; d) multi-keyed connecto
43、rs shall have multiple measurements made at each keyed position; e) patch cord connectors: in combination with the above rotations, reverse the orientation of the patch cord with respect to the direction of propagation of the light and the fixed plugs and adaptors. The number of measurements to be m
44、ade relative to the above positions shall be specified in the product standard. 5.7 Insertion loss and standard deviation shall not exceed values specified in the product standard. Req u i remen ts 8 BS EN 2591-601 12001 BSI 389 Chiswick High Road Lon don w4 4AL BSI is the independent national body
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