1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationMethod of measurement of non-linearity in resistorsBS EN 60440:2012National forewordThis British Standard is the UK implementation of EN 60440:2012. It is identi-cal to IEC 60440
2、:2012. It supersedes BS 5694:1979 which is withdrawn.The UK participation in its preparation was entrusted to Technical CommitteeEPL/40X, Capacitors and resistors for electronic equipment.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publicatio
3、n does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application. The British Standards Institution 2012Published by BSI Standards Limited 2012ISBN 978 0 580 73247 8ICS 31.040.01Compliance with a British Standard cannot confer immunity fromle
4、gal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on 30 September 2012.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 60440:2012EUROPEAN STANDARD EN 60440 NORME EUROPENNE EUROPISCHE NORM August 2
5、012 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2012 CENELEC - All rights of exploitation in any form and by any means reserved
6、worldwide for CENELEC members. Ref. No. EN 60440:2012 E ICS 31.040 English version Method of measurement of non-linearity in resistors (IEC 60440:2012) Mthode de mesure de la non-linarit des rsistances (CEI 60440:2012) Verfahren zur Messung der Nichtlinearitt von Widerstnden (IEC 60440:2012) This Eu
7、ropean Standard was approved by CENELEC on 2012-08-17. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical referen
8、ces concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a C
9、ENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugos
10、lav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 60440:2012EN 60440:2012 - 2 - Foreword
11、The text of document 40/2155/FDIS, future edition 1 of IEC 60440, prepared by IEC/TC 40 “Capacitors and resistors for electronic equipment“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 60440:2012. The following dates are fixed: latest date by which the document has to
12、 be implemented at national level by publication of an identical national standard or by endorsement (dop) 2013-05-17 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2015-08-17 Attention is drawn to the possibility that some of the elements of thi
13、s document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 60440:2012 was approved by CENELEC as a European Standard without any modification. In the off
14、icial version, for Bibliography, the following notes have to be added for the standards indicated: IEC 60027 Series NOTE Harmonised as EN 60027 Series (not modified). ISO 80000-1 NOTE Harmonised as EN ISO 80000-1. BS EN 60440:2012- 3 - EN 60440:2012 Annex ZA (normative) Normative references to inter
15、national publications with their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition o
16、f the referenced document (including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60068-1 - Environmental testing - Part 1: General and guidance EN 6006
17、8-1 - BS EN 60440:2012 2 60440 IEC:2012 CONTENTS 1 Scope . 5 2 Normative references . 5 3 Terms and definitions . 5 4 Method of measurement . 6 4.1 Measurement principle 6 4.2 Measuring circuit . 8 4.3 Measurement system requirements . 9 4.3.1 Measuring frequency . 9 4.3.2 Noise level of the measuri
18、ng system 9 4.3.3 Third harmonic ratio of the measuring system 9 4.3.4 Power amplifier 9 4.3.5 Voltmeter . 10 4.3.6 Filter 10 4.3.7 Test fixture 10 4.4 Verification of the measuring system . 10 5 Measurement procedure . 10 5.1 Environmental conditions 10 5.2 Preparation of specimen 10 5.3 Measuremen
19、t conditions 10 5.4 Procedure . 11 5.5 Precautions . 11 6 Evaluation of measurement results . 11 6.1 Evaluation . 11 6.2 Requirements 12 7 Information to be given in the relevant component specification 12 Annex A (informative) Reference to IEC/TR 60440 15 Bibliography 16 Figure 1 Equivalent circuit
20、 at the fundamental frequency . 6 Figure 2 Equivalent circuit at the third harmonic frequency 7 Figure 3 Corrective term . 8 Figure 4 Block schematic of a suitable measuring system 9 Table 1 Recommended measuring conditions (1 of 2) 13 BS EN 60440:201260440 IEC:2012 5 METHOD OF MEASUREMENT OF NON-LI
21、NEARITY IN RESISTORS 1 Scope Non-linearity testing is a method to evaluate the integrity of a resistive element. It may be applied as an effective inline screening method suitable to detect and eliminate potential infant mortality failures in passive components. The method is fairly rapid, convenien
22、t, and the associated equipment is relatively inexpensive. Typical effects causing non-linearity on resistors are e.g. inhomogeneous spots within a resistive film, traces of film left in the spiraling grooves, or contact instability between a connecting lead or termination and the resistive element.
23、 This International Standard specifies a method of measurement and associated test conditions to assess the magnitude of non-linear distortion generated in a resistor. This method is applied if prescribed by a relevant component specification, or if agreed between a customer and a manufacturer. 2 No
24、rmative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendment
25、s) applies. IEC 60068-1, Environmental testing Part 1: General and guidance 3 Terms and definitions For the puposes of this document the following terms and definitions apply. 3.1 electromotive force e.m.f. difference in potential that tends to give rise to an electric current 3.2 non-linearity devi
26、ation of a components impedance from Ohms law, resulting in voltage of harmonic frequencies when subjected to sinusoidal current 3.3 third harmonic ratio A3ratio of the fundamental voltage over the e.m.f. of the third harmonic Note 1 to entry: The third harmonic ratio is expressed in dB. Note 2 to e
27、ntry: The third harmonic ratio has been addressed before as third harmonic attenuation. This historic convention is misleading as it wrongly suggests harmonic frequencies originating from the test equipment being attenuated or filtered by the components under test. The misleading term should therefo
28、re be avoided. BS EN 60440:2012 6 60440 IEC:2012 4 Method of measurement 4.1 Measurement principle A pure sinusoidal current is passed through the component under test. If the impedance of the component is not perfectly linear, the voltage across the component will be distorted and contain harmonics
29、. One or more of these harmonics can be measured and the magnitude of these distortions is a measure of the non-linearity in the component. It is recommended to measure the third harmonic, as it is the dominant one. The third harmonic voltage appearing across a component needs to be separated from t
30、he fundamental voltage and from any other harmonic voltage for the measurement. This is accomplished by a filter circuit letting the harmonic voltage pass through while featuring very high impedance at the fundamental frequency. Also, the generator of the fundamental frequency needs to feature very
31、high impedance at the third harmonic frequency so as not to act as a load to the generated distortions. Hence, the equivalent circuit of the generator part operating at the fundamental frequency is quite simple, as shown in Figure 1. U1RTI1IEC 1432/12 Key I1Sinusoidal current U1Fundamental voltage a
32、cross the resistor under test RTImpedance of the resistor under test at the fundamental frequency Figure 1 Equivalent circuit at the fundamental frequency The equivalent circuit for the third harmonic frequency is built around the test specimen represented by a linear impedance with a zero-impedance
33、 harmonic generator in series. This signal source loads the measuring system represented by its impedance as seen from the test terminals, see Figure 2. BS EN 60440:201260440 IEC:2012 7 U3RT3R3E3IEC 1433/12 Key E3e.m.f. of the third harmonic RT3Impedance of the resistor under test at the third harmo
34、nic frequency R3Impedance of the measuring circuit at the third harmonic frequency, seen from the test terminals U3Third harmonic voltage Figure 2 Equivalent circuit at the third harmonic frequency In this circuit the e.m.f. of the third harmonic E3is divided into the measurable third harmonic volta
35、ge U3 33T333ERRRU += (1) Hence, the e.m.f. of the third harmonic E3in the component can be determined by 333T31 URRE += (2) The corrective term for the reduction of U3to the origin E3is +=33T101log20RR (3) In many cases it can be shown for a range of resistors under test that the impedance RT3at the
36、 third harmonic frequency is equal or very close to the impedance RTat the fundamental frequency. Then the corrective term in decibels is +=3T101log20RR (4) NOTE 1 For fixed film resistors this equality of RT3and RTcan generally be assumed with sufficient accuracy. Numeric values for the corrective
37、term can be obtained from Figure 3 or for specific sets of impedance R3and specimen resistance RTfrom Table 1. BS EN 60440:2012 8 60440 IEC:2012 0,1 1 10 100 0 10 20 30 40 50 RT/R3(dB)IEC 1434/12 Figure 3 Corrective term A suitable range for the fundamental frequency f1for measurements on resistors
38、is between 10 kHz and 40 kHz. This frequency range enables the test circuit to be set up without too much difficulty. NOTE 2 Another method is using a bridge which is balanced at the fundamental frequency, where the harmonics appear across the bridge diagonal. This method requires individual balanci
39、ng of the bridge for each specimen, which may be suitable for occasional use in a laboratory environment. 4.2 Measuring circuit Figure 4 shows a block schematic of a suitable measuring circuit. A distortion-free impedance matching device may be used to switch R3in order to achieve good matching to t
40、he test specimen RT. Examples of suitable values of R3are 10 ; 100 ; 1 k; 10 k and 100 k; these values are used for specifying the test conditions in Table 1. The suitability of the measuring circuit for measurements on resistors with resistance values covering a wide range depends on the lowest and
41、 highest available impedance R3 of the circuit. The range of values for R3proposed above grants suitability for measurements on specimen RTwith their resistance being in the range of 1 to at least 10 M. However, there is an overriding influence of the correcting term depending on the ratio of resist
42、ance under test RTover impedance R3, see Table 1 and Figure 3. BS EN 60440:201260440 IEC:2012 9 A VA LP BP G S V U1 V R3RTU3IEC 1435/12 Key G Oscillator, at the fundamental frequency f1S Switch for applying the test signal to the test specimen VA Variable attenuator A Power amplifier LP Low-pass fil
43、ter U1r.m.s. voltage at the fundamental frequency f1BP Band-pass filter U3r.m.s. voltage at the third harmonic frequency f3RTResistor under test R3Impedance of the measuring circuit at the third harmonic frequency f3, seen from the test terminals. Figure 4 Block schematic of a suitable measuring sys
44、tem 4.3 Measurement system requirements 4.3.1 Measuring frequency The fundamental frequency f1shall be 10 kHz and thus the third harmonic frequency f3shall be 30 kHz, unless otherwise specified in the relevant component specification. 4.3.2 Noise level of the measuring system The noise level referre
45、d to the test terminals shall not be higher than 0,2 V at R3= 1 k. 4.3.3 Third harmonic ratio of the measuring system The third harmonic ratio ( )3110log20 EU shall be higher than 140 dB for most of the impedance range when the required dissipation P is applied to a virtually linear component. The r
46、equired dissipation is 0,25 VA, as given in Table 1, or a value prescribed by the relevant component specification, e.g with reference to the rated dissipation. 4.3.4 Power amplifier The power amplifier shall be capable of delivering an apparent power of four times the required dissipation into a re
47、sistive component under test, in order to ensure sufficient linearity. Hence, the power amplifier shall be capable of delivering an apparent power of 1 VA if the required dissipation is 0,25 VA as given in Table 1. BS EN 60440:2012 10 60440 IEC:2012 4.3.5 Voltmeter The error of the voltmeter for mea
48、surement of the voltage U1at the fundamental frequency shall be less than 5 % of its full scale deflection. The error of the voltmeter for measurement of the voltage U3at the third harmonic frequency shall be less than 10 % of its full scale deflection. 4.3.6 Filter The cut-off frequency of the low-
49、pass filter shall be immediately above the fundamental freuqency f1. The band-pass filter shall permit the third-harmonic frequency f3to pass through, while it shall provide very high attenuation at the fundamental frequency f1. Precautions shall be taken to avoid non-linear distortion from the components near the test specimen in the low-pass and band-pass filters. The filter inductors for instance shall not contain cores of magnetic ma
