SIST EN IEC 60675-3:2021

SLOVENSKI STANDARD
01-marec-2021
Gospodinjski sobni neposredni grelniki - Metode za merjenje funkcionalnost - 3.
del: Dodatna določila za merjenje učinkovitosti sevanja
Household electric direct-acting room heaters - Methods for measuring performance -
Part 3: Additional provisions for the measurement of the radiation efficiency
Ta slovenski standard je istoveten z: EN IEC 60675-3:2021
ICS:
17.240 Merjenje sevanja Radiation measurements
97.100.10 Električni grelniki Electric heaters
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60675-3

NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2021
ICS 97.100.10
English Version
Household electric direct-acting room heaters - Methods for
measuring performance - Part 3: Additional provisions for the
measurement of the radiation efficiency
(IEC 60675-3:2020)
Appareils électrodomestiques de chauffage des locaux à Elektrische Haushalt-Direktheizgeräte - Prüfverfahren zur
action directe - Méthodes de mesure de l'aptitude à la Bestimmung der Gebrauchseigenschaft - Teil 3: Zusätzliche
fonction - Partie 3: Dispositions supplémentaires pour la Bestimmungen für die Messung der
mesure du rendement de rayonnement Strahlungswirkungsgrades
(IEC 60675-3:2020) (IEC 60675-3:2020)
This European Standard was approved by CENELEC on 2021-01-08. 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 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 CENELEC 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60675-3:2021 E

European foreword
The text of document 59C/257/FDIS, future edition 1 of IEC 60675-3, prepared by SC 59C "Electrical
heating appliances for household and similar purposes" of IEC/TC 59 "Performance of household and
similar electrical appliances" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 60675-3:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2021-10-08
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024-01-08
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The text of the International Standard IEC 60675-3:2020 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60531 NOTE Harmonized as EN 60531
Annex ZA
(normative)
Normative references to international publications with their
corresponding European publications
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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cenelec.eu.
Replace the references in Annex ZA of EN 60675:1995 with the following references:
Publication Year Title EN/HD Year
IEC 60675 1994 Household electric direct-acting room EN 60675 1995
heaters - Methods for measuring
performance
+ A1 1998 + A1 1998
+ A2 2018 + A2 2018
- - + A11 2019
IEC 60675-2 2020 Household electric direct-acting room EN IEC 60675-2 2021
heaters - Methods for measuring
performance - Part 2: Additional provisions
for the measurement of the radiation factor

IEC 60675-3 ®
Edition 1.0 2020-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Household electric direct-acting room heaters – Methods for measuring

performance –
Part 3: Additional provisions for the measurement of radiation efficiency

Appareils électrodomestiques de chauffage des locaux à action directe –

Méthodes de mesure de l'aptitude à la fonction –

Partie 3: Dispositions supplémentaires pour la mesure du rendement de

rayonnement
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 97.100.10 ISBN 978-2-8322-9088-0

– 2 – IEC 60675-3:2020 © IEC 2020
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and symbols. 6
4 Classification . 9
5 List of measurements . 9
6 General conditions for measurements . 9
7 Dimensions, mass and means of connection to the supply . 9
8 Temperature rises of air-outlet grilles and external surfaces . 9
9 Temperature rises of surfaces surrounding the heater . 10
10 Warming-up time of the heater. 10
11 Stability of room temperature . 10
12 Set-back . 10
13 Frost protection temperature . 10
14 Inrush current . 10
15 Effect of radiant heat . 10
15.1 Determination of radiant factor . 10
15.2 Determination of radiation efficiency . 10
16 Measurement of the usable power . 10
17 Verification of the maximum room temperature promoted by the manufacturer . 10
Annex A (normative) Climatic test room . 11
Annex B (informative) Information provided at point-of-sale . 12
Annex C (informative) Test report form . 13
Annex AA (informative) Method for measuring the radiation efficiency . 14
AA.1 General . 14
AA.2 Equations . 14
AA.2.1 Radiation efficiency . 14
AA.2.2 Dynamic factor . 16
AA.3 Classification . 17
AA.3.1 Categories . 17
AA.3.2 Type . 17
AA.3.3 List of measurements and calculations . 17
AA.4 General conditions . 17
AA.4.1 General . 17
AA.4.2 Power stabilizer . 17
AA.4.3 Multimeter . 17
AA.4.4 Variac . 18
AA.4.5 Infrared camera . 18
AA.4.6 Maximum size of active radiant heating surfaces . 18
AA.4.7 Heat-reflection devices . 18
AA.4.8 Technical data . 18
AA.4.9 Rated power . 19
AA.4.10 Testing chamber . 19
AA.5 Examinee . 19

IEC 60675-3:2020 © IEC 2020 – 3 –
AA.5.1 Declaration . 19
AA.5.2 Mounting devices, temperature control, multi-stage heater settings . 20
AA.5.3 Model series . 20
AA.5.4 Multiple active radiant heating surfaces . 21
AA.6 Test method . 21
AA.6.1 Emissivity . 21
AA.6.2 Boundary lines . 21
AA.6.3 Pixel temperature . 21
AA.6.4 Positioning . 22
AA.6.5 Steady-state operating condition . 25
AA.6.6 Calculation of the nominal radiation efficiency . 27
AA.6.7 Nominal heat-up time period . 27
AA.6.8 Dynamic factor . 28
AA.6.9 Test method . 28
AA.7 Test report . 29
AA.8 Verification system . 30
AA.8.1 General . 30
AA.8.2 Purpose of master heaters . 30
AA.8.3 Verification procedure . 30
AA.8.4 Compliance . 30
AA.9 Measuring emissivity by combining temperature reference method and
masking tape reference method . 30
AA.9.1 Combining procedure . 30
AA.9.2 The temperature reference method . 31
AA.9.3 The masking tape reference method . 31
AA.10 Measuring emissivity by using an Ulbricht sphere . 32
AA.10.1 General . 32
AA.10.2 Measurement method . 33
AA.10.3 Measurement range . 34
AA.10.4 Calculation of thermal emissivity . 34
AA.10.5 Calculation of the hemispherical emissivity . 34
AA.11 Radiant heat correction factor . 35
AA.12 Example of the test report . 36
AA.13 Example of model series test report . 41
Bibliography . 43

Figure AA.1 – Positioning of a wall-mounted heater and the infrared camera in the
testing chamber . 23
Figure AA.2 – Positioning of a ceiling-mounted heater and the infrared camera in the
testing chamber . 24
Figure AA.3 – Positioning of a floor-standing heater and the infrared camera in the
testing chamber . 25
Figure AA.4 – Schematics of a FTIR-spectrometer for measuring the directional-
spectral reflectivity of an examinee . 33
Figure AA.5 – Schematics of the reference measurement of the directional-
hemispherical spectral reflexivity . 34

Table 100 – Symbols used in this document . 9

– 4 – IEC 60675-3:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD ELECTRIC DIRECT-ACTING ROOM HEATERS –
METHODS FOR MEASURING PERFORMANCE –

Part 3: Additional provisions for the measurement of radiation efficiency

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,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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.
International Standard IEC 60675-3 has been prepared by subcommittee 59C: Electrical
heating appliances for household and similar purposes, of IEC technical committee 59:
Performance of household and similar electrical appliances.
The text of this International Standard is based on the following documents:
FDIS Report on voting
59C/257/FDIS 59C/261/RVD
Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

IEC 60675-3:2020 © IEC 2020 – 5 –
This International Standard is to be used in conjunction with IEC 60675:1994,
IEC 60675:1994/AMD1:1998 and IEC 60675:1994/AMD2:2018. This document supplements or
modifies the corresponding clauses of IEC 60675:1994. Where the text indicates an "addition"
to or a "replacement" of the relevant provision of IEC 60675:1994, these changes are made to
the relevant text of IEC 60675:1994. Where no change is necessary, the words "This clause of
IEC 60675:1994 is applicable" are used. When a particular subclause of IEC 60675:1994 is not
mentioned in this part, that subclause applies as far as is reasonable.
Additional specific provisions to those in Part 1, given as individual clauses or subclauses, are
numbered starting from 101.
NOTE The following numbering system is used:
• subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
• unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
• additional annexes are lettered AA, BB, etc.
In this document, the following print types are used:
– terms listed in Clause 3 of this document and of IEC 60675:1994 and IEC 60675-2:2020:
Arial bold.
– test specifications: in italic type.
A list of all parts in the IEC 60675 series, published under the general title Household electric
direct-acting room heaters – Methods for measuring performance, can be found on the IEC
website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://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.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

– 6 – IEC 60675-3:2020 © IEC 2020
HOUSEHOLD ELECTRIC DIRECT-ACTING ROOM HEATERS –
METHODS FOR MEASURING PERFORMANCE –

Part 3: Additional provisions for the measurement of radiation efficiency

1 Scope
This clause of IEC 60675:1994 is applicable, with the following modification:
Replace the first paragraph with the following content:
This document applies to electric direct-acting room heaters.
This document defines performance characteristics related to the radiant effect and specifies
methods for measuring the radiation efficiency for the information of users.
This document is used to measure the radiation efficiency of direct-acting room heaters.
2 Normative references
Replace Clause 2 of IEC 60675:1994 with the following content:
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.
IEC 60675:1994, Household electric direct-acting room heaters – Methods for measuring
performance
IEC 60675:1994/AMD1:1998
IEC 60675:1994/AMD2:2018
IEC 60675-2:2020, Household electric direct-acting room heaters – Methods for measuring
performance – Part 2: Additional provisions for the measurement of the radiation factor
3 Terms, definitions and symbols
Replace Clause 3 of IEC 60675:1994 with the following content:
For the purposes of this document, the terms and definitions given in IEC 60675:1994,
IEC 60675:1994/AMD1:1998, IEC 60675-2:2020 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.101
radiant factor
ratio of the measured infrared heat output to the measured total energy input, expressed in %

IEC 60675-3:2020 © IEC 2020 – 7 –
Note 1 to entry: The radiant factor can be measured for panel heaters, convector heaters and radiant heaters
3.102
radiation efficiency
ratio of the heat flow into a (testing) chamber by radiation exchange between an active radiant
heating surface and the inner surfaces of the chamber to the nominal electric power of a heater
inside this testing chamber
Note 1 to entry: The radiant factor and the radiation efficiency are measured on different physical background
and not comparable.
3.103
active radiant heating surface
room-facing surfaces of heaters
Note 1 to entry: Areas with average temperatures below 40 °C, like frames, mounting devices, operation panels,
and other additions, shall be excluded from being part of the respective active radiant heating surface.
3.104
rated power
electrical input Q in W, measured in steady-state conditions calculated as the average of the
M
electrical input during the measurement of the radiation efficiency over the period necessary
for confirming steady-state conditions
Note 1 to entry: Steady-state conditions are reached when the heater's surface temperature does not vary by more
than 1 K over 10 min.
3.105
emissivity
ratio of radiant flux of a specific surface as compared to the radiant flux of a standard black
body, at the same temperature and in the same environment
3.106
examinee
heater that is being tested in accordance with this document
3.107
infrared camera
measurement device for recording and pictorial representation of the surface temperatures of
heaters
3.108
low temperature infrared heater
heater without visibly glowing parts, with one or more active radiant heating surfaces, each
with an average temperature between 40 °C and 200 °C, and a nominal radiation efficiency
of 40 % or higher as determined by this document
Note 1 to entry: “Without visibly glowing parts" denotes that, in case of an installed heater, those parts cannot be
detected with the naked eye from a point situated 2 m in front of the heater and 1,2 m above the floor.
3.109
model
heater with the identical construction and appearance as other heaters made by the same
manufacturer
3.110
model series
group of models
– 8 – IEC 60675-3:2020 © IEC 2020
3.111
nominal heat-up time
time period from turning-on the heater until arriving at 2/3 of the temperature in the steady-
state operating condition of the heater
3.112
nominal radiation efficiency
ratio of the heat flow into a testing chamber by radiation exchange between an active radiant
heating surface and the inner surfaces of the chamber to the nominal electric power of a heater
inside this testing chamber
Note 1 to entry: For calculation of the nominal radiation efficiency, see AA.2.1.1.
3.113
dynamic factor
parameter that can be used for benchmarking of low temperature infrared heaters
Note 1 to entry: This parameter is based on the nominal radiation efficiency and the nominal heat-up time.
Note 2 to entry: For the calculation of the dynamic factor, see AA.2.2.
3.114
radiant heat correction factor
parameter that specifies how much of the radiant flux of a heater is absorbed in the air
3.115
steady-state operating condition
status of heater with steady-state operating temperature of its active radiant heating surfaces
over a predetermined period of time
3.116
testing chamber
standardized environment for testing heaters
3.117
corrected radiation efficiency
nominal radiation efficiency reduced by the influence of absorption in air.
Note 1 to entry: For calculation of the corrected radiation efficiency, see AA.2.1.2.
3.118
relative radiation efficiency
ratio of the nominal radiation efficiency of the test device to the radiation efficiency of an
idealized version of the test device
Note 1 to entry: For calculation of the relative radiation efficiency, see AA.2.1.3.
3.119 Symbols
The symbols given in Table 100 are used in this document.

IEC 60675-3:2020 © IEC 2020 – 9 –
Table 100 – Symbols used in this document
Symbol Designation Dimension
P Electric nominal power W
elnom
P Measured electrical input in steady-state conditions W
el
L Length m
W Width m
D Depth m
-- Length of power cable m
-- Weight kg
A Active radiant heating surface
m
pixel
ε Hemispherical emissivity of an active radiant heating surface --
h
−8 2 4
σ
Stefan-Boltzmann constant (= 5,670 4 × 10 )  W / m K
T Infrared camera image-pixel temperature of an active radiant heating surface K
front
T Simple average temperature of all 6 interior surfaces of the testing chamber K
wall
A
Radiant heat correction factor for radiant heat absorption in air --
TOT
Φ Radiant flux after applying the radiant heat correction factor W
radc
R Nominal radiation efficiency %
nom
D Dynamic factor --
f
t
Nominal heat-up time minutes
nom
s Repetitive precision W
o
s Comparative precision W
m
4 Classification
This clause of IEC 60675:1994 is applicable.
5 List of measurements
This clause of IEC 60675:1994 and IEC 60675:1994/AMD1:1998 is applicable.
6 General conditions for measurements
This clause of IEC 60675:1994 and IEC 60675:1994/AMD1:1998 is applicable.
7 Dimensions, mass and means of connection to the supply
This clause of IEC 60675:1994 is applicable.
8 Temperature rises of air-outlet grilles and external surfaces
This clause of IEC 60675:1994 is applicable.

– 10 – IEC 60675-3:2020 © IEC 2020
9 Temperature rises of surfaces surrounding the heater
This clause of IEC 60675:1994 is applicable.
10 Warming-up time of the heater
This clause of IEC 60675:1994 is applicable.
11 Stability of room temperature
This clause of IEC 60675:1994 and IEC 60675:1994/AMD1:1998 is applicable.
12 Set-back
This clause of IEC 60675:1994 is applicable.
13 Frost protection temperature
This clause of IEC 60675:1994 is applicable.
14 Inrush current
This clause of IEC 60675:1994 is applicable.
Replace Clause 15 of IEC 60675:1994 with the following content:
15 Effect of radiant heat
15.1 Determination of radiant factor
For panel heaters, convector heaters and radiant heaters the radiant factor shall be
determined in accordance with Annex AA of IEC 60675-2:2020.
15.2 Determination of radiation efficiency
For low temperature radiant heaters, the radiation efficiency may be determined in
accordance with Annex AA of this document.
16 Measurement of the usable power
This clause of IEC 60675:1994/AMD1:1998 is applicable.
17 Verification of the maximum room temperature promoted by the
manufacturer
This clause of IEC 60675:1994/AMD2:2018 is applicable.

IEC 60675-3:2020 © IEC 2020 – 11 –
Annex A
(normative)
Climatic test room
This annex of IEC 60675:1994 is applicable.

– 12 – IEC 60675-3:2020 © IEC 2020
Annex B
(informative)
Information provided at point-of-sale
This annex of IEC 60675:1994 and the modifications in IEC 60675:1994/AMD1:1998 and
IEC 60675:1994/AMD2:2018 apply.

IEC 60675-3:2020 © IEC 2020 – 13 –
Annex C
(informative)
Test report form
The following content replaces the content of Annex C of IEC 60675:1994:
See Test report according to Annex AA of this document.

– 14 – IEC 60675-3:2020 © IEC 2020
Annex AA
(informative)
Method for measuring the radiation efficiency
AA.1 General
This annex is based on the fact that electric heaters are traded in the market based on their
performance characteristics. One such characteristic is the nominal radiation efficiency,
which is becoming increasingly important. For purposes of comparison, this annex specifies a
test method for the nominal radiation efficiency.
This annex covers:
– heaters with a maximum electric nominal power of 3 kW;
– heaters with radiant surface temperatures of at least 40 °C and up to 200 °C;
– heaters with one or more active radiant heating surface;
– heaters with or without an integrated or external room temperature control;
– heaters with a radiant surface that is plane or curved in any way;
– heaters with a radiant surface that includes any kind of recesses, protrusions or holes;
– heaters with a radiant surface that consists partially or entirely of a mesh;
– heaters with a radiant surface that consists partially or entirely of different materials;
– heaters with a radiant surface that consists partially or entirely of different colours;
– heaters that are fixed or portable;
– heaters used indoors;
– heaters used in residences, offices, hotels, motels, bed and breakfasts, restaurants;
kindergartens, schools; sales shops, supermarkets, and similar environments.
This annex does not cover:
– heaters with active radiant surface temperatures of more than 200°C (for these kinds of
heaters, IEC 60675-2 shall be used to measure the radiant factor) (see 3.101),
– electric thermal-storage heaters (IEC 60531),
– electric heating appliances integrated into the building structure,
– electric central heating systems,
– electric heaters connected to an air duct,
– wallpaper, paint, carpets and drapes incorporating electric heating technologies.
AA.2 Equations
AA.2.1 Radiation efficiency
AA.2.1.1 Nominal radiation efficiency
Equation (AA.1) for the nominal radiation efficiency is incident to Equation (AA.5) as follows:
∑Φ
rad
R = × 100 (AA.1)
nom
P
el
IEC 60675-3:2020 © IEC 2020 – 15 –
with
2 2 4 4 4
Φ (W) = A (m ) × ε (--) × σ (W / m K ) × (T (K) − T (K)) (AA.2)
rad pixel h front wall
where
R is the nominal radiation efficiency in (%)
nom
Φ is the radiant flux of each single pixel of the infrared camera image in (W)
rad
P is the rated power in (W)
el
A is the respective active radiant heating surface of the heater in (m )
pixel
ε is the hemispherical emissivity of active radiant heating surfaces in the spectral
h
wavelength of at least 2,5 μm to 35 μm (--)
2 4
σ is the Stefan-Boltzmann constant in (W / m K )
T is the temperature of an infrared camera image-pixel at an active radiant heating
front
surface in (K)
T is the mean temperature of all six interior surface temperatures of the testing chamber
wall
in (K)
Equation (AA.2) for Φ is applied to every single pixel of every infrared camera image of each
rad
active radiant heating surface. The total of all Φ is the given heat flow and is used in
rad
Equation (AA.1).
AA.2.1.2 Corrected radiation efficiency
Equation (AA.3) for the corrected radiation efficiency is incident to Equation (AA.5) as
follows:
∑Φ
radc
R (%) = × 100 (AA.3)
nomc
P
el
with
2 2 4 4 4
Φ (W) = A (m ) × ε (--) × σ (W / m K ) × (T (K) − T (K)) × A (--) (AA.4)
radc pixel h front wall TOT
with A in accordance with Clause AA.11.
TOT
where
R is the corrected radiation efficiency in %;
nomc
Φ is the corrected radiant flux of each single pixel of the infrared camera image in W;
radc
P is the rated power in W;
el
A is the respective active radiant heating surface of the heater in m ;
pixel
ε is the hemispherical emissivity of active radiant heating surfaces in the spectral
h
wavelength of at least 2,5 μm to 35 μm (--)
2 4
K ;
σ is the Stefan-Boltzmann constant in W / m
T is the temperature of an infrared camera image-pixel at an active radiant heating
front
surface in K;
– 16 – IEC 60675-3:2020 © IEC 2020
T is the mean temperature of all six interior surface temperatures of the testing chamber
wall
in K;
is the radiant heat correction factor (--).
A
TOT
is applied to every single pixel of every infrared camera image of
Equation (AA.4) for Φ
radc
each active radiant heating surface. The total of all Φ is the given heat flow and is used
radc
in Equation (AA.3).
AA.2.1.3 Relative radiation efficiency
The relative radiation efficiency is determined in accordance with Equation (AA.5):
R = R / R (AA.5)
rel nom idealized
where:
R is the relative radiation efficiency in %;
rel
R is the nominal radiation efficiency in %;
nom
R is defined as 70 %.
idealized
AA.2.1.4 Nominal radiation efficiency at lower power levels
The values of radiation efficiency according to AA.2.1.1 – AA.2.1.3, can be measured and
stated at lower power levels also.
In this case, the radiation efficiency at steady-state conditions at 20 %, 50 %, or 80 % of the
rated power shall be used.
The formulas and the measurement process stay the same.
The information of the power level shall be given with the resulting values.
NOTE For heaters with more than one heating element, the average power of each heating element shall be
measured during the tests for amplitude and drift of IEC 60675-1. The power distribution between the different
heating elements shall be determined. These power levels for the heating elements shall be used for steady state
conditions at the lower power levels. If these conditions cannot be realized by the integrated controls, the different
heating elements must be activated by variacs with the power levels determined during the tests of part 1.
AA.2.2 Dynamic factor
The dynamic factor is based on the following Equation (AA.6):
R
nom
QK = × (AA.6)
f
t
nom
where
Q is the dynamic factor (--);
f
R is the nominal radiation efficiency in %;
nom
t is the nominal heat-up time in minutes and seconds, with seconds displayed as
nom
double-digit minute-decimal;
K is the factor of 1 min/%.
IEC 60675-3:2020 © IEC 2020 – 17 –
AA.3 Classification
AA.3.1 Categories
– Electric low temperature infrared heaters
AA.3.2 Type
– Fixed
– Portable
In the case of portable heaters, at least the front and the back side of the heater shall be
measured if they are active radiant heating surfaces. If applicable and of relevance, other
sides can be measured also.
For heaters that can be operated as fixed and as portable heaters, the mounting conditions
shall be stated in combination with the measurement results.
The test report should state the category, type, and kind of mounting of the heater.
AA.3.3 List of measurements and calculations
Performance is determined by means of the following measurements and calculations:
– size of the active radiant heating surfaces,
– weight of the heater,
– length of the power cord,
– rated power,
– average temperature of the inside surfaces of the testing chamber,
– calculation of the nominal heat-up time period
– calculation of the nominal radiation efficiency,
– calculation of the dynamic factor,
– determination of the classification.
AA.4 General conditions
AA.4.1 General
The measurements are performed with the appliance mounted in accordance with the
manufacturer’s instructions set at the nominal output as declared by the manufacturer and under
the conditions given in AA.4.2 to AA.4.11.
AA.4.2 Power stabilizer
To ensure that the heater achieves the steady-state operating temperature as designed by the
manufacturer, a power stabilizer keeps the supply voltage steady at mains voltage during the
entire testing period. The power stabilizer should have an output power of up to 3 kW, with an
accuracy of at least ±1 % of the measured voltage.
AA.4.3 Multimeter
For measuring electric power, a TrueRMS-multimeter should be used. The multimeter should
have a load capacity of up to 3 kW, with an accuracy of at least ±1 % of the measured value.
Power values may be recorded at least once every 5 s, simultaneously with the infrared camera
images.
– 18 – IEC 60675-3:2020 © IEC 2020
AA.4.4 Variac
For heaters with an integrated on/off control, a manually or automatically operated variac with
an output power of up to 3 kW should be used to establish a steady-state operating condition
of the heater.
AA.4.5 Infrared camera
The infrared camera should have a minimum resolution of 640 pixels × 480 pixels.
The infrared camera should have a spectral range of 7 μm up to 13 μm, with a tolerance of
±1 μm.
The infrared camera should have the following accuracy:
– from 20 °C up to 100 °C average temperature, a maximum of ±2 °C relating to the measured
value,
– from 101 °C up to 200 °C average temperature, a maximum of ±2 % relating to the measured
value.
At least once every 5 s, simultaneously with multimeter recordings, the infrared camera should
automatically record an infrared image from an active radiant heating surface.
The infrared camera should be calibrated in accordance with the instructions, at least once
before every verification test.
The test report should state make and model of the infrared camera, the resolution, the
spectral range, accuracy, and the last calibration date.
AA.4.6 Maximum size of active radiant heating surfaces
Pertaining to current heater sizes offered on the market and included in the scope of this annex,
the maximum size of any active radiant heating surface is limited to a plane surface or its
equivalent of 2 m × 1,3 m, or a cylinder or similar shaped surface with a diameter of 1,3 m ×
2 m, or a spherical or similar shaped surface of 1,3 m in diameter, or a triangle or similar shaped
surface with of 1,3 m × 2 m.
For heaters exceeding the size of 1,3 m in the horizontal direction, the infrared camera shall be
turned by 90°.
AA.4.7 Heat-reflection devices
Should the heater have a heat-reflection device at the backside of the heater, and the device
is also mentioned in the heater manual, then this device may be used in conjunction with the
heater for testing purposes.
AA.4.8 Technical data
The following technical data of a heater should be supplied with the heater, and should be
stated in the test report:
– the length, width and depth of each active radiant heater surface in m, rounded-off to
0,005 m;
– the weight of the heater in kg, rounded-off to one decimal;
– the electri
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