IEC TS 63350:2022

Household electric appliances - Specification of the properties of a digital system for measuring the performance

IEC TS 63350:2022 specifies generic requirements for creating a digital system that is used for measuring the characteristics of visually detectable performance, such as browning intensity and lightness.
It defines the metrological requirements of this digital system and demonstrates the procedures for compliance. The digital system contains the measuring instrument, the software, and the reference materials necessary to realize the measurement process.
References to this document can be made by a customer when specifying the digital system and by the suppliers when specifying products offered.
Interested parties can agree to use this document as an input for satisfying measurement management system requirements in any activities.
The principles of ISO 10012 are followed to ensure the capability of the systems.
Currently, this document focuses on test methods described in IEC 60350-1 and IEC 60350-2 but further applications based on visually detectable performance criteria might be supplemented.

General Information

• Status: Published
• Publication Date: 10-Oct-2022
• ICS: 97.040.20 - Cooking ranges, working tables, ovens and similar appliances
• Technical Committee: SC 59K - Performance of household and similar electrical cooking appliances
• Drafting Committee: WG 4 - TC 59/SC 59K/WG 4
• Current Stage: PPUB - Publication issued
• Start Date: 11-Nov-2022
• Completion Date: 11-Oct-2022

Standards Content (Sample)

IEC TS 63350
®

Edition 1.0 2022-10
TECHNICAL
SPECIFICATION



Household electric appliances – Specification of the properties of a digital
system for measuring the performance
IEC TS 63350:2022-10(en)

---------------------- Page: 1 ----------------------
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IEC TS 63350

®


Edition 1.0 2022-10




TECHNICAL



SPECIFICATION



















Household electric appliances – Specification of the properties of a digital

system for measuring the performance


























INTERNATIONAL

ELECTROTECHNICAL


COMMISSION





ICS 97.040.20 ISBN 978-2-8322-5849-1




  Warning! Make sure that you obtained this publication from an authorized distributor.


® Registered trademark of the International Electrotechnical Commission

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– 2 – IEC TS 63350:2022 © IEC 2022
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Test setup . 8
4.1 Illumination . 8
4.2 Measurement environment . 9
5 Determination of shade charts . 9
5.1 Principals of shade creation . 9
5.2 Brown shade charts . 10
5.3 Green shade charts . 11
6 Measurements . 13
6.1 Verification of evenness . 13
6.2 Lightness recognition (L* values) . 14
6.2.1 Description of the test samples . 14
6.2.2 Procedure . 14
6.2.3 Evaluation (requirements and tolerances) . 14
6.3 Colour recognition (L*, a*, b* values) . 14
6.3.1 Description of the test samples . 14
6.3.2 Procedure . 15
6.3.3 Evaluation (requirements and tolerances) . 15
6.4 Verification of the measurement area . 15
6.4.1 General . 15
6.4.2 Description of the test samples . 15
6.4.3 Procedure . 15
6.4.4 Evaluation (requirements and tolerances) . 15
6.5 Verification of the resolution. 15
6.6 Verification of rectilinear projection . 16
6.7 Verification of the 3-dimensional shapes . 16
7 Data to be recorded (raw data) . 17
7.1 Purpose . 17
7.2 LAB . 17
7.3 HLC . 17
7.4 ∆E for the test sample . 17
00
7.5 Dimensions (in mm) . 17
7.6 Specified measurement areas . 17
8 Consideration of tolerances . 18
8.1 General . 18
8.2 Calculation of differences in colour and its components . 18
8.3 Distance information . 19
Annex A (normative) Colour-measuring instrument . 20
Annex B (informative) Brown shade charts . 22
Annex C (informative) Green shade charts . 24
Annex D (informative) Evaluation program for determining the deviation in colour
rendering . 26

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IEC TS 63350:2022 © IEC 2022 – 3 –
Annex E (informative) Examples of shade chart positioning for lightness recognition . 27
Bibliography . 28

Figure 1 – Cone shape of colour sample . 16
Figure 2 – 13 sections of the colour sample . 17
Figure A.1 – Colour measuring instrument di:8° . 20
Figure A.2 – Colour measuring instrument 45°:0° . 21
Figure E.1 – Example with an assessment area of 100 mm × 100 mm – 1 position per
row and column . 27
Figure E.2 – Example with an assessment area of 150 mm × 150 mm – 2 positions per
row and column . 27
Figure E.3 – Example with an assessment area of 470 mm × 370 mm – 4 positions per
row and column . 27

Table 1 – Brown shade charts with class limits . 11
Table 2 – Green shade charts . 12
Table 3 – Maximum CIELAB hue angle distance inside different ∆E* ranges . 19
ab
Table B.1 – CIELAB Values for the brown shade charts . 22
Table C.1 – CIELAB Values for the green shade charts . 24

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– 4 – IEC TS 63350:2022 © IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

HOUSEHOLD ELECTRIC APPLIANCES –

Specification of the properties of a digital system
for measuring the performance

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 63350 has been prepared by subcommittee SC 59K: Performance of household and similar
electrical cooking appliances, of IEC technical committee TC 59: Performance of household
and similar electrical appliances. It is a Technical Specification.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
59K/350/DTS 59K/356/RVDTS

Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Specification is English.

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IEC TS 63350:2022 © IEC 2022 – 5 –
In this document, the following print types are used:
• terms defined in Clause 3: bold type.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at https://www.iec.ch/members_experts/refdocs. The main document types developed by IEC
are described in greater detail at https://www.iec.ch/standardsdev/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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– 6 – IEC TS 63350:2022 © IEC 2022
INTRODUCTION
IEC subcommittee 59K has agreed to make a collection of existing and future requirements on
a digital system used in testing the performance of appliances under the scope of SC 59K,
cooking appliances.
This document bundles the generic requirements given in IEC 60350-1 and IEC 60350-2 that
are updated, aligned, and supplemented by further requirements. The reference colour system
is changed from a proprietary colour system to the standardized and widely used CIELAB-based
reference colour system.
The intention with this publication is to ensure that using a digital system, which complies with
the stated requirements and described methods, leads to reproducible results.
Currently, this document focuses on test methods described in IEC 60350-1 and IEC 60350-2
but further applications based on visually detectable performance criteria might be
supplemented.

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IEC TS 63350:2022 © IEC 2022 – 7 –
HOUSEHOLD ELECTRIC APPLIANCES –

Specification of the properties of a digital system
for measuring the performance



1 Scope
This document specifies generic requirements for creating a digital system that is used for
measuring the characteristics of visually detectable performance, such as browning intensity
and lightness.
It defines the metrological requirements of this digital system and demonstrates the
procedures for compliance. The digital system contains the measuring instrument, the
software, and the reference materials necessary to realize the measurement process.
References to this document can be made by a customer when specifying the digital system
and by the suppliers when specifying products offered.
Interested parties can agree to use this document as an input for satisfying measurement
management system requirements in any activities.
NOTE 1 The principles of ISO 10012 are followed to ensure the capability of the systems.
NOTE 2 Possible suppliers for the recommended digital system can be found in the supplementary file located at:
https://www.iec.ch/sc59k/supportingdocuments
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
CIE 15, Colorimetry
ISO 12647-7, Graphic technology – Process control for the production of half-tone colour
separations, proof and production prints – Part 7: Proofing processes working directly from
digital data
ISO 15076-1, Image technology colour management – Architecture, profile format and data
structure – Part 1: Based on ICC.1:2010
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp

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– 8 – IEC TS 63350:2022 © IEC 2022
3.1
digital system
system that is used for measuring the characteristics of visually detectable performance
3.2
assessment area
area of the digital system within which the requirements stated in this document shall be met
and the items under test are positioned
3.3
shade chart
sample representing the reference values for the colour and lightness recognition and used for
calibration of the digital system
3.4
items under test
IUT
objects positioned in the assessment area for evaluation
EXAMPLE 1 Shortbread, small cakes, broccoli, white bread, in accordance with IEC 60350-1.
EXAMPLE 2 Floured disc, in accordance with IEC 60350-2.
3.5
terms and definitions of international lighting vocabulary
L* CIELAB lightness
a*, b* CIELAB a*, b* coordinates
C* CIELAB chroma
ab
h CIELAB hue angle
ab
∆L* CIELAB lightness difference
∆E* CIELAB colour difference
ab
∆E CIEDE2000 colour difference
00
4 Test setup
4.1 Illumination
The measurement is taken under an illumination similar to the CIE Standard Illuminate used for
the definition of the shade charts (see Clause 5).
The maximum calculated deviation of rendering the shade charts under the used light shall be
∆L* ≤ 1 for a measurement system for lightness recognition, and ∆E ≤ 5 for a measurement
00
system for colour recognition.
To calculate the deviation of the colour rendering, the 10° tristimulus values of the reference
colours shall be calculated with the spectral distribution of the reference colours defined in the
corresponding performance test for the relative spectral power distribution of CIE D65 and the
relative spectral power distribution of the test setup illumination. The calculation shall be
performed from 400 nm to 700 nm with a step of increment no more than 10 nm.
Test setup illumination spectral power distribution measurement is made on the central axis of
the beam, and with the sensing surface normal to this direction. The spectroradiometer sensing
surface is placed at a distance which ensures sufficient light for a measurement to be taken

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IEC TS 63350:2022 © IEC 2022 – 9 –
while eliminating any stray light. The light shall stabilise before measurements are made (e.g.
stable temperature).
Spectral distribution of the reference colours for the calculation shall be acquired with a diffuse
eight-degree geometry, specular component included measurement mode (di:8°) spectrometer
in accordance with CIE 15.
NOTE 1 Necessary information on calculating the tristimulus, spectral distribution of D65, L*, a*, b* and ∆E can
00
be found in the ISO 11664 series.
1
An Excel evaluation program, which corresponds to the described method, is available as an
example for the automatic calculation of the deviation of the colour rendering for measured light
spectra from at least 400 nm to 700 nm with a step of increment 10 nm; see Annex D. This
document includes the light spectra of the proposed reference colours of this document and the
light spectra of the CRI calculation colours (CIE 15).
NOTE 2 The supplementary file for the described method is located at:
https://www.iec.ch/sc59k/supportingdocuments.
4.2 Measurement environment
During the measurements, no movable items other than the IUT shall be near or inside the
assessment area. The assessment area shall be kept as constant as possible since every
item can alter the illumination by absorption or reflection.
5 Determination of shade charts
5.1 Principals of shade creation
Shade charts represent the reference values for the colour and lightness recognition. Since
the recognition is based on classes, the shade chart shall represent the centre point of each
class.
For recognition based on 1-dimensional classes (e.g. L*), the values of the defined reference
colour shall be in the centre of the boundaries of each class. This is achieved by mathematically
creating the reference colours along a line in the 3-dimensional CIELAB colour space.
For recognition based on multiple dimensions within the CIELAB colour space, the defined
reference colours shall be located with equal distances within a space defined by at least 3
coordinates. The equal distancing between the defined colours shall be based on at least two
values of the CIELAB system (ISO/CIE 11664-4). This results in a colour gradient with a linear
step size in at least 2 dimensions.
Defined colours shall be printed in accordance with the proof process described in ISO 12647-
7 on matt proofing paper simulating PS5 (print substrate 5 in accordance with ISO 12647-2) as
spot colours. The printed colour samples shall be calibrated with a diffuse eight-degree
geometry, specular component included measurement mode (di:8°) spectrometer CIE 15 and
shall be in a range of ∆L* ≤ 1,5 if used as reference colours for the lightness recognition and
∆E ≤ 5 if used as reference colours for the colour recognition.
00
Proof process defined in ISO 12647-7 is referring to spectral measurement defined in
ISO 13655 which is (45°:0°) or (0°:45°) geometry and D50 reference illumination. For proper
colour communication, conversion of the colour information to a reference colour space
__________
1
Excel is the trade name of a product supplied by Microsoft Corporation. This information is given for the
convenience of users of this standard and does not constitute an endorsement by IEC of the product named.
Equivalent products may be used if they can be shown to lead to the same results.

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– 10 – IEC TS 63350:2022 © IEC 2022
described in ISO 15076-1 is necessary. Converted values and the applied conversion models
for the exemplary shade charts shown in this document can be found in Annex B and Annex C.
Created shade charts shall be within the limits of the sRGB colour space.
NOTE 1 Requirements for colour measuring instruments in accordance with CIE 15 for (di:8°) and (45°:0°) or
(0°:45°) geometry can be found in Annex A.
NOTE 2 Necessary information on transforming the CIEXYZ colour space to sRGB can be found in IEC 61966-2-1
and transforming the CIELAB colour space to the CIEXYZ colour space can be found in ISO 11664-4.
5.2 Brown shade charts
Brown shade charts are used to verify the lightness recognition of the digital measurement
system. The relevant value for the brown shade charts is L*.
The ∆L* of each defined colour step shall be equal. To achieve a linear colour gradient between
L*
 
 
the defined colours the a* coordinates shall lie on a line that connects at least 2 (maximum
 
 
b*
 
4) reference colours within the 3-dimensional CIELAB colour space. This results in a uniform
Euclidean distance (∆E* ) of the points that lie on the same line.
ab
As an example, the calculated values of 14 reference colours located on 2 lines based on 3 L*,
a* and b* coordinates are shown in Table 1.
L* 27,8 60,7 88,9
      
      
In the example, the 3 defined a* coordinates are 6,4 , 16,4 , 2,9 .
      
      
b* 4,4 33,0 27,0
      

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IEC TS 63350:2022 © IEC 2022 – 11 –
Table 1 – Brown shade charts with class limits
Shade Lower Upper
No. L* limit L* limit
∆E*
L* a* b* ∆L* for for R G B
ab
shade shade
class class
17 27,8 6,4 4,4  0 30,15  78 62 59
16 32,5 7,9 8,5 4,7 30,15 34,85 6,4 93 72 63
15 37,2 9,3 12,6 4,7 34,85 39,55 6,4 109 82 67
14 41,9 10,7 16,7 4,7 39,55 44,25 6,4 125 92 71
13 46,6 12,1 20,8 4,7 44,25 48,95 6,4 141 102 76
12 51,3 13,6 24,8 4,7 48,95 53,65 6,4 157 113 80
11 56,0 15,0 28,9 4,7 53,65 58,35 6,4 174 124 84
10 60,7 16,4 33,0 4,7 58,35 63,05 6,4 190 135 88
9 65,4 14,1 32,0 4,7 63,05 67,75 5,3 200 148 101
8 70,1 11,9 31,0 4,7 67,75 72,45 5,3 210 162 115
7 74,8 9,6 30,0 4,7 72,45 77,15 5,3 219 177 128
6 79,5 7,4 29,0 4,7 77,15 81,85 5,3 229 191 142
5 84,2 5,1 28,0 4,7 81,85 86,55 5,3 238 205 156
4 88,9 2,9 27,0 4,7 86,55 100,00 5,3 248 220 171

The proof process defined in ISO 12647-7 is referring to the spectral measurement defined in
ISO 13655, which is (45°:0°) or (0°:45°) geometry and D50 reference illumination. For proper
colour communication, conversion of the colour information to a reference colour space
described in ISO 15076-1 is necessary. Converted values and the applied conversion models
for the shade charts shown in Table 1 can be found in Annex B.
5.3 Green shade charts
Green shade charts are used to verify the colour recognition of the digital measurement
system. The relevant value for the green shade charts is CIELAB hue angle (h ) which is the
ab
arcus tangent of b* and a* axis in the CIELAB colour space in degrees.
The CIELAB hue angle difference of each defined colour step shall be equal. For each defined
CIELAB hue angle step, a linear colour gradient between the defined colours the HLC (h , L*
ab
) coordinates shall lie on a line that connects at least 2 reference points.
and C*
ab
Mathematically created colours within a radius of ∆E* ≤ 2,5 towards each other are not
ab
considered for the printing process, since these differences cannot be adequately reproduced
by the proof printing process.
As an example, the calculated values of 43 reference colours located on 7 lines based on 3
HLC coordinates are shown in Table 2.

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– 12 – IEC TS 63350:2022 © IEC 2022
Fix points of the individual colour gradients are set by h , L* and C*
ab ab
h
ab h  h 
ab ab

   
*
The example colour gradient coordinates in L , are from 25 , 60 where the defined

   

   
*
 10 60
C    
ab
CIELAB hue angle steps for the green shades are from h = 88° to h = 130° with a step size
ab ab
of 7°, giving a total of 7 individual colour gradients.
The colours on the colour gradients can be extracted by defining either L* or C* steps. As an
ab
example, colours are extracted from the colour gradients with an L* step size of 5 are calculated
and shown in Table 2.
The step size of 5 results in 49 colours, of which 6 have to be disregarded since the distance
between the colours is ∆E* ≤ 2,5.
ab
The proof process defined in ISO 12647-7 is referring to spectral measurement defined in
ISO 13655, which is (45°:0°) or (0°:45°) geometry and D50 reference illumination. For proper
colour communication, conversion of the colour information to a reference colour space
described in ISO 15076-1 is necessary. Converted values and the applied conversion models
for the exemplary shade charts shown in Table 2 can be found in A
...