BSI Standards Publication Photovoltaic devices Part 1 0 Methods of l inearity measurement BS EN 60904 1 0 201 0 National foreword This British Standard is the UK implementation of EN 60904 1 0 201 0 I[.]
BS EN 60904-1 0:201 BSI Standards Publication Photovoltaic devices Part 0: Methods of linearity measurement BS EN 60904-1 0:201 BRITISH STANDARD National foreword This British Standard is the UK implementation of EN 60904-1 0:201 It is identical to IEC 60904-1 0:2009 It supersedes BS EN 60904-1 0:1 998 which is withdrawn The UK participation in its preparation was entrusted to Technical Committee GEL/82, Photovoltaic Energy Systems A list of organizations represented on this committee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application © BSI 201 ISBN 978 580 64380 ICS 27.1 60 Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 201 Amendments issued since publication Amd No Date Text affected BS EN 60904-1 0:201 EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 60904-1 March 201 ICS 27.1 60 Supersedes EN 60904-1 0:1 998 English version Photovoltaic devices Part 0: Methods of linearity measurement (IEC 60904-1 0:2009) Dispositifs photovoltaïques Partie 0: Méthodes de mesure de la linéarité (CEI 60904-1 0:2009) Photovoltaische Einrichtungen Teil 0: Messverfahren für die Linearität (IEC 60904-1 0:2009) This European Standard was approved by CENELEC on 201 0-03-01 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 references concerning such national standards may be obtained on application to the Central Secretariat 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 CENELEC member into its own language and notified to the Central Secretariat 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Central Secretariat: Avenue Marnix 17, B - 000 Brussels © 201 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members Ref No EN 60904-1 0:201 E BS EN 60904-1 0:201 EN 60904-1 0:201 -2- Foreword The text of document 82/582/FDIS, future edition of IEC 60904-1 0, prepared by IEC TC 82, Solar photovoltaic energy systems, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60904-1 on 201 0-03-01 This European Standard supersedes EN 60904-1 0:1 998 The main technical changes with regard to the EN 60904-1 0:1 998 are as follows: – Added clause for two-lamp method for Isc linearity – Changed standard deviation as a metric for linearity to percent deviation from linearity This was done because a non-linear device can have a low standard deviation and percent deviation is the quantitative number that matters for the parameter of interest – Removed clause on spectral responsivity nonlinearity because it is not used by any PV testing / calibration group For testing real PV devices it is difficult to make this error significant in the spectral mismatch correction factor while still passing Isc linearity Measuring the responsivity over the entire response range means that the device will probably fail the temperature linearity near the band edge – Added a clause to allow short circuit linearity with temperature or total irradiance to be determined from absolute spectral responsivity measurements This data is routinely reported in PTB primary reference cell calibration certificates – Added report clause in compliance with ISO/IEC 7025 requirements – Often the temperature coefficient of short circuit current is very small so measurement errors can result in percent deviations outside the accepted range Therefore, the following text was added to 7.3c): “If the temperature coefficient of short circuit current is less than 0,1 %/K, then the device can be considered linear with respect to this parameter.” Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CEN and CENELEC shall not be held responsible for identifying any or all such patent rights The following dates were fixed: – latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 201 0-1 2-01 – latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 201 3-03-01 Annex ZA has been added by CENELEC Endorsement notice The text of the International Standard IEC 60904-1 0:2009 was approved by CENELEC as a European Standard without any modification In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 60904-7 NOTE Harmonized as EN 60904-7 IEC 61 829 NOTE Harmonized as EN 61 829 -3- BS EN 60904-1 0:201 EN 60904-1 0:201 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of 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 IEC 60891 Year - IEC 60904-1 - IEC 60904-3 - IEC 60904-8 - IEC 60904-9 - IEC 61 21 - IEC 61 646 - ISO/IEC 7025 - Title EN/HD Photovoltaic devices - Procedures for EN 60891 temperature and irradiance corrections to measured I-V characteristics Photovoltaic devices EN 60904-1 Part : Measurement of photovoltaic currentvoltage characteristics Photovoltaic devices EN 60904-3 Part 3: Measurement principles for terrestrial photovoltaic (PV) solar devices with reference spectral irradiance data Photovoltaic devices EN 60904-8 Part 8: Measurement of spectral response of a photovoltaic (PV) device Photovoltaic devices EN 60904-9 Part 9: Solar simulator performance requirements Crystalline silicon terrestrial photovoltaic (PV) EN 61 21 modules - Design qualification and type approval Thin-film terrestrial photovoltaic (PV) EN 61 646 modules - Design qualification and type approval General requirements for the competence of EN ISO/IEC 7025 testing and calibration laboratories Year - - BS EN 60904-1 0:201 –2– 60904-1 I EC: 2009 CONTENTS Scope and obj ect N orm ative references Apparatus Sam ple selection Procedure for current and voltage linearity test Procedure in natural sunlight Procedure with a solar sim ulator Procedure for short-circuit linearity from absolute spectral responsivity Procedure for short-circuit current linearity from two-lam p m ethod Background Apparatus - Light sources A and B General procedure Linearity calculation Slope linearity determ ination Determ ination of the short circuit current linearity using the two lam p m ethod 1 Linearity requirem ents 1 Report 1 Bibliography BS EN 60904-1 0:201 60904-1 I EC: 2009 –5– PHOTOVOLTAIC DEVICES – Part 0: Methods of linearity measurement Scope and object This part of I EC 60904 describes procedures used to determ ine the degree of linearity of any photovoltaic device param eter with respect to a test param eter I t is prim arily intended for use by calibration laboratories, m odule m anufacturers and system designers Photovoltaic (PV) m odule and system perform ance evaluations, and perform ance translations from one set of tem perature and irradiance conditions to another frequently rely on the use of linear equations (see I EC 60891 and I EC 61 829) This standard lays down the linearity requirem ents and test m ethods to ensure that these linear equations will give satisfactory results I ndirectly, these requirem ents dictate the range of the tem perature and irradiance variables over which the equations can be used The m ethods of m easurem ent described in this standard apply to all PV devices and are intended to be carried out on a sam ple or on a com parable device of identical technology They should be perform ed prior to all m easurem ent and correction procedures that require a linear device The m ethodology used in this standard is sim ilar to that specified in I EC 60891 in which a linear (straight-line) function is fitted to a set of data points using a least-squares fit calculation routine The variation of the data from this function is also calculated, and the definition of linearity is expressed as an allowable variation percentage A device is considered linear when it m eets the requirem ents of General procedures for determ ining the degree of linearity for these and any other perform ance param eter are described in Clauses and Normative references The following referenced docum ents are indispensable for the application of this docum ent For dated references, only the edition cited applies For undated references, the latest edition of the referenced docum ent (including any am endm ents) applies I EC 60891 , Photovoltaic devices – Procedures for temperature and irradiance corrections to measured I-V characteristics I EC 60904-1 , characteristics Photovoltaic devices – Part 1: Measurement of photovoltaic current-voltage Photovoltaic devices – Part 3: Measurement principles for terrestrial photovoltaic (PV) solar devices with reference spectral irradiance data I EC 60904-3, I EC 60904-8, Photovoltaic devices – Part 8: Measurement of spectral response of a photovoltaic (PV) device I EC 60904-9, Photovoltaic devices – Part 9: Solar simulator performance requirements I EC 61 21 5, Crystalline silicon terrestrial photovoltaic (PV) modules – Design qualification and type approval BS EN 60904-1 0:201 –6– I EC 61 646, approval I EC: 2009 Thin-film terrestrial photovoltaic (PV) modules – Design qualification and type I SO/I EC 7025, laboratories 60904-1 General requirements for the competence of testing and calibration Apparatus a) Equipm ent necessary to m easure an I -V curve (see I EC 60904-1 ) b) Any equipm ent necessary to change the irradiance over the range of interest without affecting the relative spectral irradiance distribution and the spatial uniform ity, such as m esh filters or neutral density filters N OTE The equ i pm ent and proced ure u sed to ch an ge the i rrad i an ce are to be verifi ed wi th a radi om eter Th e change i n rel ati ve spectral i rradi ance di stri bu ti on shoul d n ot resu l t i n m ore th an 0, % ch an ge i n the sh ortci rcui t cu rren t of the devi ce (see I EC 60904-7 an d I EC 60904-8) Mesh fil ters are bel i eved to be the best m ethod for l arge surfaces c) Any equipm ent necessary to change the tem perature of the test specim en over the range of interest d) A m eans for controlling the tem perature of the test specim en and reference device, or a rem ovable shade e) Equipm ent for m easuring the spectral response of the test specim en (or a representative sam ple equivalent to the test specim en) in accordance with I EC 60904-8 to a repeatability of ± % of the reading N OTE I EC 60904-7 provi d es m eth ods for the com putati on of spectral m i sm atch error i n trod uced i n the testi n g of ph otovol tai c d evi ces, an d I EC 60904-8 provi des gu i dance for spectral m easurem ent Sample selection This procedure shall be applied to a full-sized test specim en if possible I f this is not possible, a sm all sam ple equivalent in construction and m aterials should be used Procedure for current and voltage linearity test There are three acceptable procedures for perform ing the linearity test of short-circuit current with respect to tem perature and irradiance There are two acceptable procedures for perform ing the linearity test of open-circuit voltage with respect to tem perature and irradiance 5.1 Procedure in natural sunlight 5.1 – – – Measurem ent in natural sunlight shall only be m ade when: The total irradiance is at least as high as the upper lim it of the range of interest The irradiance variation caused by short-term oscillations (clouds, haze, or sm oke) is less than ± % of the total irradiance as m easured by the reference device The wind speed is less than m ⋅ s –1 5.1 Mount the reference device co-planar with the test specim en so that both are norm al to the direct solar beam within ± ° Connect to the necessary instrum entation N OTE The m easu rem en ts d escri bed i n the fol lowi n g subcl au ses sh ou l d be m ade as expedi ti ou sl y as possi bl e wi th i n a few h ou rs on th e sam e d ay to m i ni m i ze th e effect of chan ges i n the spectral di ti on s I f n ot, spectral correcti ons m ay be req ui red 5.1 I f the test specim en and reference device are equipped with tem perature controls, set the controls at the desired level I f tem perature controls are not used, shade the test specim en from the sun and allow it to stabilize within ± °C of the am bient air tem perature The BS EN 60904-1 0:201 60904-1 I EC: 2009 –7– reference device should also stabilize within proceeding ± °C of its equilibrium tem perature before Rem ove the shade (if used) and im m ediately take sim ultaneous readings of the test param eter Xi , the test specim en device param eter Yi and the tem perature and short-circuit current of the reference device The irradiance G o shall be calculated from the m easured short circuit current ( Isc ) of the PV reference device, and its calibration value at Standard Test Conditions, STC ( Irc ) A correction should be applied to account for the tem perature of the reference device Tm using the current-tem perature coefficient of the reference device α rc Go = 000 × Isc Irc × [1 − α rc (Tm − 25 )] I f the test param eter being varied is the irradiance, reduce the irradiance on the test specim en to a known fraction ki without affecting the spatial uniform ity or the spectral irradiance distribution There are various m ethods by which to accom plish this: a) U sing calibrated, uniform density m esh filters I f this m ethod is selected, the reference device should rem ain uncovered by the filter during the operation to enable the incident irradiance to be m easured I n this case, ki is the filter calibration param eter (fraction of light transm itted) b) U sing uncalibrated, uniform density m esh filters I f this m ethod is selected, the reference device should also be covered by the filter during the test I n this case, ki is the ratio of the reference device short-circuit current ( Isc ) to its calibration value ( Irc ) N OTE Th e m axi m um fi l ter m esh open i ng d i m ensi on sh ou l d be l ess th an % of the m i ni m u m li n ear di m ensi on of th e referen ce d evi ce an d th e test speci m en, or a vari abl e error m ay occur du e to posi ti oni ng c) By controlling the angle of incidence I f this m ethod is selected, the reference device should have the sam e reflective properties as the test specim en, and should be m ounted co-planar with the test specim en within ± ° I n this case, ki is the ratio of the reference device shortcircuit current ( Isc ) to its calibration value ( Irc ) N OTE For cells wi th th ick m etal lization , the rotati on axis sh ou ld be parallel to the d i recti on of th e m etalized l i n es i n ord er to m i ni m i ze or el i m i n ate sh ad owin g Calculate the irradiance level on the test specim en Gi where Go = ki Gi as follows: × Go is determ ined by the m ethod described in I f the test param eter being varied is the tem perature, adj ust the tem perature by m eans of a controller or alternately exposing and shading the test specim en as required to achieve and m aintain the desired tem perature Alternately, the test specim en m ay be allowed to warm up naturally with the data recording procedure of perform ed periodically during the warm up Ensure that the test specim en and reference device tem peratures are stabilized and rem ain constant within ± °C and that the irradiance as m easured by the reference device rem ains constant within ± % during the data recording periods Repeat steps through The value of the test param eter selected shall be such that the range of interest is spanned in at least four approxim ately equal increm ents A m inim um of three m easurem ents shall be m ade at each of the test conditions BS EN 60904-1 0:201 –8– 5.2 60904-1 I EC: 2009 Procedure with a solar simulator N OTE Em i ssi on l am ps su ch as xen on shoul d be eval u ated before u se As the ban d gap of the test d evi ce vari es due to tem perature ch an ges, i t can pass th rough vari ou s em i ssi on l i n es i n the l am p spectru m and gi ve ri se to shi fts i n perform ance Based on the l i neari ty of spectral response and the l am p spectrum th e m agn i tude of th i s effect can be cal cu l ated by perform i ng a m i sm atch correcti on as a fu ncti on of tem perature 5.2.1 Mount the test specim en and the reference device co-planar in the test plane of the sim ulator so that both are norm al to the center line of the beam within ± ° Connect to the necessary instrum entation 5.2.2 I f the test specim en and reference device are equipped with tem perature controls, set the controls at the desired level I f tem perature controls are not used, allow the test specim en and reference device to stabilize within ± °C of the room air tem perature 5.2.3 Set the irradiance at the test plane to the upper lim it of the range of interest using the reference device m easured current ( Isc ), and its calibration value at STC ( Irc ) 5.2.4 Conduct the test and take sim ultaneous readings of the test param eter Xi , the test specim en device param eter Yi and the tem perature and short-circuit current of the reference device 5.2.5 The irradiance G o shall be calculated from the m easured short circuit current ( Isc ) of the PV reference device, and its calibration value at STC ( Irc ) A correction should be applied to account for the tem perature of the reference device Tm , using the current-tem perature coefficient of the reference device α rc Go = 000 × Isc Irc × [1 − α rc (Tm − 25 )] 5.2.6 I f the test param eter being varied is the irradiance, reduce the irradiance on the test specim en to a known fraction ki without affecting the spatial uniform ity or the spectral irradiance distribution The various methods by which to accom plish this are: a) by increasing the distance between the test plane and the lam p With the reference device m aintained in the sam e plane as the test specim en, ki is the ratio of the reference device short-circuit current ( Isc ) to its calibration value ( Irc ); b) by the use of an optical lens I n this case, ki is the ratio of the reference device short-circuit current ( Isc ) to its calibration value ( Irc ) Care should be exercised to ensure that the lens does not significantly change the relative spectral irradiance in the wavelength range in which the test and reference specim ens are responsive; c) by controlling the angle of incidence I f this m ethod is selected, the distance between the lam p source and the specim en shall be large to lim it the irradiance change across the tilted surface to 0, % or less Also, if this m ethod is selected, the radiant beam shall be collim ated, the reference device should have the sam e reflective properties as the test specim en, and should be m ounted co-planar with the test specim en I n this case, ki is the ratio of the reference device short-circuit current ( Isc ) to its calibration value ( Irc ); d) calibrated, uniform density m esh filters I f this m ethod is selected, the reference device should rem ain uncovered by the filter during the operation to enable the incident irradiance to be m easured I n this case, ki is the filter calibration param eter (fraction of light transm itted); e) uncalibrated, uniform density m esh filters I f this m ethod is selected, the reference device should also be covered by the filter during the test I n this case, ki is the ratio of the reference device short-circuit current ( Isc ) to its calibration value ( Irc ) N OTE The m axim um fi l ter m esh openi ng d i m en si on shoul d be less th an % of th e m i n i m um li n ear di m ension of the reference devi ce and th e test speci m en, or a vari abl e error m ay occur d ue to posi ti on i ng 5.2.7 Calculate the irradiance level on the test specim en Gi as follows: BS EN 60904-1 0:201 60904-1 I EC: 2009 –9– Gi where Go = ki × Go is determ ined by the m ethod described in 5 5.2.8 I f the test param eter being varied is the tem perature, adjust the tem perature by appropriate m eans (see of I EC 61 21 and I EC 61 646) 5.2.9 Ensure that the test specim en and reference device tem peratures are stabilized and rem ain constant within ± °C during the test 5.2.1 Repeat steps through The value of the test param eter selected shall be such that the range of interest is spanned in at least four approxim ately equal increm ents A m inim um of three m easurem ents shall be m ade at each of the test conditions 5.3 Procedure for short-circuit linearity from absolute spectral responsivity Following I EC 60904-8 m easure the absolute spectral responsivity as a function of bias light or tem perature in at least four approxim ately equal increm ents over the tem perature or irradiance range of interest Com pute the short-circuit current density by integrating the m easured responsivity with the reference spectrum given in I EC 60904-3 Procedure for short-circuit current linearity from two-lamp method 6.1 Background I f a PV device is linear then the short circuit current (photo-current) from a cell illum inated by two light sources shall equal the sum of the short circuit currents (photo-currents) from the individual light sources or; IA + IB = IAB where: IAB IA or IB is the short-circuit current with both lam ps illum inating the cell, is the short-circuit current with one lam p on the cell and the light from the other lam p blocked N OTE The ad vantage of thi s m eth od i s that no fil ter or lam p properti es have to be m easu red 6.2 Apparatus - Light sources A and B For specim ens that are single j unction cells the spatial nonuniform ity of the light or spectral irradiance is not im portant For specim ens that are m odules, two I EC 60904-9 class BBA or better light sources are required The tem poral instability of the light shall be less than 0, % during the m easurem ent period of IAB , IA and IB 6.3 General procedure 6.3.1 Connect the test specim en to the apparatus to m easure Isc 6.3.2 Set the test specim en tem perature to the value of interest, and m aintain within 6.3.3 ± °C Adj ust the light sources to give the desired irradiance and allow the light sources to stabilize The best results will be obtained when the two light sources produce approxim ately the sam e short circuit current N OTE The i rradi ance m ay be ch an ged usi ng fi l ters or by changi ng the l i ght i nten si ti es BS EN 60904-1 0:201 – 10 – 60904-1 I EC: 2009 6.3.4 Measure I*AB , I*A , I*B and Iroom (the short circuit current with both beam s blocked) with a given com bination of filters or intensities for light source A and light source B Calculate: IAB = I*AB – Iroom IA = I*A – Iroom IB = I*B – Iroom 6.3.5 Repeat steps 3 and with values of irradiance leading to short circuit currents IA and IB equivalent to the IAB of the previous step 6.3.6 Continue the process (steps 3 to 5) until the range of irradiances of interest has been spanned N OTE I n order to get m ore d ata poi n ts i n th e ran ge of i n terest, an y com bi nati on of val ues of i rrad i an ce l ead i ng to short ci rcu i t cu rrents IA and IB m easured in steps to 6 can then be utilized Linearity calculation Verify that any variable param eters other than the one being evaluated were held constant during the testing Sm all changes in tem perature or irradiance m ay be corrected analytically to the desired condition using I EC 60891 This can be an iterative process which should be updated when linearity is established and when m ore refined correction coefficients are determ ined 7.1 Slope linearity determination For perform ance characteristic slopes such as the open-circuit voltage versus tem perature, or short-circuit current versus irradiance, calculate linearity using the following m ethod: 7.1 Calculate the m ean values of the test param eters, and the characteristics of the best-fit straight line using the least-squares fit m ethod as follows: Step : Com pute the m ean value of the X and Y data points as follows: = ∑= = ∑= n X i Xi n n Y i Yi n where n is the num ber of m easurem ents Step 2: Com pute the slope, m , of the best fit line as follows: ∑= (X − X) ⋅ (Y − Y ) ∑= (X − X) n m = i i i n i i Step 3: The best-fit straight line, also known as the regression line, can now be written as follows: BS EN 60904-1 0:201 60904-1 I EC: 2009 – 11 – Y – Ŷi = m × ( X – Xi ) N OTE Ŷ i s th e predi cted val ue based on the fi t N OTE Thi s i s equ i val ent to Ŷi = mXi + b wi th b = Y – mX 7.1 The percentage variation from linearity is determ ined using the best fit straight line slope, m , and the m easured data as follows: Percentage deviation from linearity = 00 where typical { Xi , Yi } pairs are { Isc , 7.2 G i } or { Pm ax, × [1 – Yi / Ŷ] T} Determination of the short circuit current linearity using the two lamp method Expressing the deviation as a percentage deviation from linearity, D li n yields; D l i n = 00 × [( IAB – Iroom ) / ( IA + IB – × Iroom ) – ] There is a value of D l i n for each intensity 7.3 Linearity requirements When a given device is claim ed to be linear, the applicable range of tem peratures, irradiance, voltage, or other necessary conditions shall also be stated The requirem ents for the acceptable lim its of non-linearity (variation) are: a) For the curve of short-circuit current versus irradiance, the m axim um deviation from linearity should be less than % b) For the curve of open-circuit voltage versus the logarithm of irradiance, the m axim um deviation from linearity should be less than % c) For the curve of open-circuit voltage, short-circuit current and m axim um power versus tem perature, the m axim um deviation from linearity should be less than % I f the tem perature coefficient of short circuit current is less than 0, %/K, the device can be considered linear with respect to this param eter Report Following com pletion of the procedure, a certified report of the perform ance tests, with m easured characteristics shall be prepared by the test agency in accordance with the procedures of I SO/I EC 7025 Each certificate or test report shall include at least the following inform ation a) A title b) N am e and address of the test laboratory and location where the calibration or tests were carried out c) U nique identification of the certification or report and of each page d) N am e and address of client, where appropriate e) Description and identification of the item calibrated or tested f) Characterization and condition of the calibration or test item g) Date of receipt of test item and date(s) of calibration or test, where appropriate h) I dentification of calibration or test m ethod used i) Reference to sam pling procedure, where relevant j) Any deviations from , additions to or exclusions from the calibration or test m ethod, and any other inform ation relevant to a specific calibration or test, such as environm ental conditions BS EN 60904-1 0:201 – 12 – 60904-1 I EC: 2009 k) Measurem ents, exam inations and derived results of m odule incidence angle effects, its operating tem perature and its spectral response l) For non-sym m etric optical m odules the tilt and azim uth directions have to be specified in a drawing m ) A statem ent of the estim ated uncertainty of the calibration or test result (where relevant) n) A signature and title, or equivalent identification of the person(s) accepting responsibility for the content of the certificate or report, and the date of issue o) Where relevant, a statem ent to the effect that the results relate only to the item s calibrated or tested p) A statem ent that the certificate or report shall not be reproduced except in full, without the written approval of the laboratory q) A statem ent on whether the sam ple passes or fails the linearity criteria And the deviation from linearity r) Graph of the data used to determ ine linearity in BS EN 60904-1 0:201 60904-1 I EC: 2009 – 13 – Bibliography Photovoltaic devices – Part 7: Computation of the spectral mismatch correction for measurements of photovoltaic devices I EC 60904-7, Crystalline silicon photovoltaic (PV) array – On-site measurement of I-V characteristics I EC 61 829, _ This page deliberately left blank This page deliberately left blank NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW British Standards Institution (BSI) BSI is the national body responsible for preparing British Standards and other standards-related publications, information and services BSI is incorporated by Royal Charter British Standards and other standardization products are published by BSI Standards Limited About us We bring together business, industry, government, consumers, innovators and others to shape their combined experience and expertise into standards -based solutions The knowledge embodied in our standards has been carefully assembled in a dependable format and re f ned through our open consultation process Organizations of all sizes and across all sectors choose standards to help them achieve their goals Information on standards We can provide you with the knowledge that your organization needs to succeed Find out more about British Standards by visiting our website at bsigroup.com/standards or contacting our Customer Services team or Knowledge Centre Buying standards You can buy and download PDF versions of BSI publications, including British and adopted European and international standards, through our website at bsigroup.com/shop, where hard copies can also be purchased If you need international and foreign standards from other Standards Development Organizations, hard copies can be ordered from our Customer Services team Subscriptions Our range of subscription services are designed to make using standards easier for you For further information on our subscription products go to bsigroup.com/subscriptions Revisions Our British Standards and other publications are updated by amendment or revision We continually improve the quality of our products and services to bene f t your business If you f nd an inaccuracy or ambiguity within a British Standard or other BSI publication please inform the Knowledge Centre Copyright All the data, software and documentation set out in all British Standards and other BSI publications are the property of and copyrighted by BSI, or some person or entity that owns copyright in the information used (such as the international standardization bodies) and has formally licensed such information to BSI for commercial publication and use Except as permitted under the C opyright, Designs and Patents Act 988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means – electronic, photocopying, recording or otherwise – without prior written permission from BSI Details and advice can be obtained from the Copyright & Licensing Department Useful Contacts: Customer Services Tel: +44 845 086 9001 Email (orders): orders@bsigroup com Email (enquiries): cservices@bsigroup com Subscriptions Tel: +44 845 086 9001 Email: subscriptions@bsigroup com With British Standards Online (BSOL) you’ll have instant access to over 55,000 British and adopted European and international standards from your desktop It’s available 24/7 and is refreshed daily so you’ll always be up to date Knowledge Centre Tel: +44 20 8996 7004 Email: knowledgecentre@bsigroup com You can keep in touch with standards developments and receive substantial discounts on the purchase price of standards, both in single copy and subscription format, by becoming a BSI Subscribing Member Copyright & Licensing Tel: +44 20 8996 7070 Email: copyright@bsigroup com PLUS is an updating service exclusive to BSI Subscribing Members You will automatically receive the latest hard copy of your standards when they’re revised or replaced To f nd out more about becoming a BSI Subscribing Member and the bene f ts of membership, please visit bsigroup.com/shop With a Multi-User Network Licence (MUNL) you are able to host standards publications on your intranet Licences can cover as few or as many users as you wish With updates supplied as soon as they’re available, you can be sure your documentation is current For further information, email bsmusales@bsigroup.com BSI Group Headquarters 389 Chiswick H igh Road Lond on W4 4AL U K