1、Glass in building Coated glass Part 2: Colour of faade Verre dans la construction Verre couche Partie 2: Couleur des faades ISO 2011 Reference number ISO 11479-2:2011(E) First edition 2011-10-01 ISO 11479-2 INTERNATIONAL STANDARDISO 11479-2:2011(E)COPYRIGHT PROTECTED DOCUMENT ISO 2011 All rights res
2、erved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the reque
3、ster. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2011 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of nat
4、ional standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. Interna
5、tional organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the r
6、ules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by a
7、t least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 11479-2 was prepared by Technic al Committee IS
8、O/TC 160, Glass in building, Subcommittee SC 1, Product considerations. ISO 11479 consists of the following parts, under the general title Glass in building Coated glass: Part 1: Physical defects Part 2: Colour of faade ISO 11479-2:2011(E) ISO 2011 All rights reserved iiiIntroduction It is known tha
9、t faades incorporating coated glass can present different shades of the same colour, an effect that can be amplified when observed under an angle. Possible causes of differences in colour include slight variations in the colour of the substrate onto which the coating is applied and slight variations
10、 in thickness of the coating itself. Furthermore, for highly selective coatings, a slight variation in thickness can create a difference in colour, visible due to the high sensitivity of the human eye. The purpose of this International Standard is to avoid any subjective approaches that might have b
11、een used in the past. This is achieved through the use of spectroscopic techniques and defined evaluation practices. All measured values concern the finished glass product as installed in the faade and not the single components. ISO 11479-2:2011(E)iv ISO 2011 All rights reservedINTERNATIONAL STANDAR
12、D ISO 11479-2:2011(E) Glass in building Coated glass Part 2: Colour of faade 1 Scope This part of ISO 11479 specifies a method for objective evaluation of the colour of coated glass when used in faades and viewed from the outside, as well as for measuring colour differences within the same glass pan
13、e and between two adjacent panes in the same faade. This part of ISO 11479 does not specify requirements for determining colour differences of transmitted colour as viewed from the inside or outside of a faade, nor for internal reflected colour. The comparison should only be undertaken for panes of
14、the same glass type, composition and interior conditions and situated in the same plane of a faade. Specific requirements are given for coated glass, dependent upon its light transmittance and reflectance. This part of ISO 11479 is not applicable to curved or bent glass, which is specifically exclud
15、ed for technical reasons. NOTE Information on the perception, quantification and measurement of colour is given in Annex A. 2 Symbols NOTE The following symbols form part of the colour measurement system used in this part of ISO 11479, which is based on ISO 11664-4:2008 (CIE S 014-4/E:2007). 2.1 L*
16、lightness assuming a value between 0 and 100 NOTE L* = 0 is black, L* = 100 is white. 2.2 a* colour definition between green and magenta NOTE Negative a* is green, positive a* is red. 2.3 b* colour definition between blue and yellow NOTE Negative b* is blue, positive b* is yellow. 2.4 E ab * Euclide
17、an distance between the points representing two colours in the CIE L* a* b* colour space 3 In situ colour measurement The following paragraphs explain the procedures used on site for measuring the colour of the glass product. Information on the perception, quantification and measurement of colour is
18、 given in Annex A. ISO 2011 All rights reserved 13.1 Colour differences within the same glass pane For colour differences within the same glass pane, the parameters L*, a* and b* shall be measured with a portable colorimeter or spectrophotometer. The measurements shall be undertaken at a minimum of
19、three points in each zone representing the colour difference. NOTE 1 An example is illustrated in Figure 1. Measurements shall not be undertaken at any point within 10 cm of an edge due to the potential for colour near the edge to differ slightly from the colour in the centre. However, for glass coa
20、ted as fixed dimensions, measurements shall not be undertaken nearer than 15 cm from an edge. NOTE 2 Measurements can be affected by the proximity of the frame and the edge of the insulating glass unit. The L*, a*, b* and E ab * values shall be calculated based on the difference between the average
21、values for each zone, in accordance with Equations (1), (2), (3) and (4), respectively. L* = L* (zone 2) L* (zone 1)(1) a* = a* (zone 2) a* (zone 1)(2) b* = b* (zone 2) b* (zone 1)(3) ab E * * * 2 22 L ab(4) The values of L*, a* and b* shall meet the requirements given in 3.3. 1 2 X 1 X 2 X 3 Y 1 Y
22、2 Y 3 Key 1 zone 1 2 zone 2 Figure 1 Example of measurements undertaken at a minimum of three points in each zone representing the colour difference 3.2 Colour differences between two adjacent panes in the same faade The comparison should only be undertaken for panes of the same glass type, composit
23、ion and interior conditions and situated in the same plane of a faade. NOTE 1 Interior refers to the ambient lighting inside the building. NOTE 2 The reference pane can be compared with any of the eight adjacent panes, horizontal, vertical and diagonal. ISO 11479-2:2011(E)2 ISO 2011 All rights reser
24、vedFor colour differences between two adjacent panes, the parameters L*, a* and b* shall be measured with a portable colorimeter or spectrophotometer. For each pane representing the colour difference, the measurements shall be undertaken at a minimum of three points, e.g. along a diagonal. NOTE 3 An
25、 example is illustrated in Figure 2. The average values of L*, a* and b* shall be determined for each pane. NOTE 4 An example is detailed in Table 1. Table 1 Example of determining the average values of L*, a* and b* for one pane, e.g. Y Pane Y L* a* b* Measuring point Y 1 L* Y1 a* Y1 b* Y1 Measurin
26、g point Y 2 L* Y2 a* Y2 b* Y2 Measuring point Y 3 L* Y3 a* Y3 b* Y3 Average L* pane Y= ( L* Y1+ L* Y2+ L* Y3 )/3 a* pane Y= ( a* Y1+ a* Y2+ a* Y3 )/3 b* pane Y= ( b* Y1+ b* Y2+ b* Y3 )/3 X 1 X 2 X 3 Y 1 Y 2 Y 3 X Y Key X pane X Y pane Y Figure 2 Example of measurements undertaken at a minimum of thr
27、ee points for each pane representing the colour difference The L*, a* and b* values shall be calculated based on the difference between the average values for each pane, in accordance with Equations (5), (6) and (7), respectively. L* = L* (pane Y) L* (pane X)(5) a* = a* (pane Y) a* (pane X)(6) b* =
28、b* (pane Y) b* (pane X)(7) where X is the reference pane. The values of L*, a* and b* shall meet the requirements given in 3.3. ISO 11479-2:2011(E) ISO 2011 All rights reserved 3The value of E ab * shall be calculated from the L*, a* and b* values calculated from Equations (5), (6) and (7) using Equ
29、ation (4). 3.3 Requirements for colour The values of L*, a*, b* and E ab * are determined in accordance with 3 .1 and 3.2 and shall meet the requirements given in Table 2. Table 2 Requirements for colour L* 5,0 a* 5,0 b* 5,0 E ab * 6,0 3.4 Angle dependency of colour The colour of solar-control glass
30、, particularly that with a high selectivity, varies with the angle of observation. These variations can only be measured in a laboratory on small samples and shall not be undertaken in situ. Therefore, this part of ISO 11479 reflects colour measurements at normal incidence angles only. ISO 11479-2:2
31、011(E)4 ISO 2011 All rights reservedAnnex A (informative) Perception, quantification and measurement of colour A.1 Perception of colour The perception of colour can be very subjective and linked to the impression and perception of the individual, the sensitivity of the eye being a very personal char
32、acteristic. A variety of conditions affect how a colour looks, for instance when observing the faade of a building from the outside, including: luminosity, e.g. a dark overcast sky might reveal colour differences not observed under direct sunlight; distance and angle of observation; type and colour
33、of mullions and transoms used in the faade; distance between two adjacent glass panes; the eye of the observer; internal conditions, e.g. the absence of lighting in the building, i.e. dark background, may increase the perception of colour differences; external conditions, e.g. the presence of other
34、buildings that may be reflected by the glass. Care should be taken to avoid observing the faade under conditions which are not representative for a building “in use”. Alternatively, due account should be taken of these factors during the assessment. A.2 Quantification of colour As noted in A .1, a v
35、isual observation of colour invariably has a subjective element. Therefore, it is very important to be able to quantify the colour of a faade in order to develop an approach that is independent of this subjectivity. Various methods have been devised in the past for quantifying colour and expressing
36、it numerically with the aim of making it easier and more accurate. The method used in this part of ISO 11479 is the L* a* b* colour space, defined by the CIE in 1976. As the colour of an object is dependent upon the light source, the standard illuminant adopted by this part of ISO 11479 is D65 (repr
37、esenting average daylight) and the angle of observation is 10. The L* a* b* colour space (also referred to as CIELAB) is one of the most popular colour spaces for measuring object colour and is widely used in a variety of fields. It provides a procedure for evaluating uniform colour differences in r
38、elation to visual differences and, moreover, it enables colour to be quantified. This colorimetric system can be visualized by a three-dimensional colour space, where every colour can be represented by a set of three coordinates: L*, a* and b*, where L* indicates the lightness and a* and b* the chro
39、maticity coordinates. Positive values of a* show the red direction, and negative values the green direction, whereas positive values of b* show the yellow direction and negative values the blue direction. The centre is achromatic, i.e. neutral. NOTE The parameters L*, a* and b* can be used for quant
40、ifying the aesthetics of a faade, observed from the outside (in reflection), or to characterize the properties of light transmission through a glass pane. ISO 11479-2:2011(E) ISO 2011 All rights reserved 5The differences of colour can be quantified using tolerances on the parameters L*, a* and b*, w
41、hich are noted as L*, a* and b*, respectively, and calculated as in Equations (A.1), (A.2) and (A.3): L* = L* object 2 L* object 1(A .1) a* = a* object 2 a* object 1(A.2) b* = b* object 2 b* object 1(A.3) In the field of colour measurement, it is common to refer to a E ab * value combining L*, a* an
42、d b* values. A.3 Measurement of colour The parameters L*, a* and b* can be measured by spectrophotometers used in the laboratory. Similar instruments such as spectrometers or colorimeters can be portable instruments, suitable for use on site and as instructed by the manufacturer. Whether used in a l
43、aboratory or on site, these devices have a similar sensitivity to that of the human eye. The measurements should always be undertaken with the same light source and illumination method to ensure that the measurement conditions are the same, regardless of whether it is day or night, indoors or outdoo
44、rs. This ensures that simple and accurate measurements are undertaken to provide numerical values that are independent of external factors (as listed in A .1). NOTE Portable instruments currently used on site are limited to the measurement of colour in reflection, with an angle of observation corres
45、ponding to the vertical. Laboratory instruments can measure the characteristics of glass panes in transmission and reflection under different angles of observation. ISO 11479-2:2011(E)6 ISO 2011 All rights reservedBibliography 1 ISO 11664-4:2008 (CIE S 014-4/E:2007), Colorimetry Part 4: CIE 1976 L*a*b* Colour space ISO 11479-2:2011(E) ISO 2011 All rights reserved 7ISO 11479-2:2011(E) ICS 81.040.20 Price based on 7 pages ISO 2011 All rights reserved
