EN IEC 61308:2026
(Main)High-frequency dielectric heating installations - Test methods for the determination of power output
General Information
- Abstract
This document specifies test methods for the determination of useful high frequency power output in equipment for industrial heating and processing of materials. It is in particular applicable to HF generators made available to users as separate units.
This document is basically applicable to equipment operating in the frequency range 100 kHz to 300 MHz, as defined in IEC 60519-1, with the following limitations.
– This document does not apply to induction heating, which it is possible to carry out in the lower part of the specified frequency band.
– The ISM centre frequencies for dielectric heating and processing of industrial interest are narrow bands about 6,78 MHz, 13,56 MHz, 27,12 MHz and 40,68 MHz.
– This document is not applicable to:
• appliances for household and similar use;
• commercial use;
• laboratory use;
• medical high frequency equipment.
For equipment working in designated ISM bands, it is a legal requirement that the frequency remains within the ISM bands according to CISPR 11, but the resonant frequency of the circuit varies with the change of dielectric parameters of the load. Therefore, the value of the mean output power in the work cycle can be much lower than the value obtained under the test conditions. This value depends upon the response of the tuning system.
NOTE 1 The following criteria are suitable for determination of the classification as industrial equipment:
– commercial equipment is typically designed and planned for series production of many identical units;
– industrial equipment is typically produced in small series or even as single units; the processed goods are consumed or ready for final use at the end of the heating process.
NOTE 2 Heating a workload with dielectric parameters which change significantly in time and/or with temperature, the value of the output power obtained with the actual charge can be different from that obtained with the test load specified in this document.
This document relates to equipment normally operating under continuous rated conditions.
- Status
- Published
- Publication Date
- 17-Sep-2026
- Technical Committee
- CLC/SR 27 - Industrial electroheating equipment
- Current Stage
- 6060 - Document made available - Publishing
- Start Date
- 18-Sep-2026
- Due Date
- 19-Dec-2025
- Completion Date
- 18-Sep-2026
Overview
EN IEC 61308:2026, published by CLC, specifies standardized test methods for determining the useful power output of high-frequency dielectric heating installations. Applicable mainly to industrial electroheating equipment, particularly high-frequency generators operating within the range of 100 kHz to 300 MHz, this standard ensures reliable and comparable measurement results for manufacturers, users, and regulatory bodies.
Dielectric heating is commonly used for rapid and uniform heating of non-conductive materials such as plastics, textiles, wood, and ceramics. Accurate determination of power output is critical for process quality, energy efficiency, and workplace safety in industrial applications.
Key Topics
Scope and Applicability
- Applies to industrial high-frequency dielectric heating equipment, particularly HF generators provided as standalone units.
- Excludes induction heating, household, commercial, laboratory, and medical HF equipment.
Defining Test Loads
- Calorimetric load: Substitutes real load to measure output using water as an absorbing medium, appropriate for powers over 1 kW.
- Lamp load: Uses incandescent lamps as a test load for measuring output up to about 1 kW.
- Matched resistive load: Utilizes specially matched resistors for direct power output measurement.
- Wet-sand load: Simulates a real industrial load with wet sand to evaluate useful output power.
- Plastic welding test electrode: Used specifically for assessing output in dielectric plastic welding applications.
Test Methods
- Procedures for load substitution, power calculation, thermal equilibrium, and ensuring measurement accuracy.
- Recommendations on setting up test circuits, critical measurement points, and conditions for reliable output assessment.
- Detailed approaches for both type A (separable generator and applicator) and type B (integrated generator) equipment.
Measurement Accuracy
- Emphasizes methods that achieve a typical measurement accuracy within ±5% for calorimetric, lamp, and resistive load methods.
- Notes higher variability (±10% to ±20%) for wet-sand load measurements.
Applications
EN IEC 61308:2026 is essential for:
- Manufacturers: Ensuring equipment meets designated output specifications and complies with international measurement standards.
- Industrial Users: Verifying actual performance parameters for process optimization and product quality control.
- Testing Laboratories: Providing a standard framework for comparative assessments and certification processes.
- Regulatory Compliance: Supporting conformity with related safety and electromagnetic compatibility (EMC) requirements.
Common sectors utilizing these methods include plastic welding, wood lamination, textile drying, ceramic processing, and other industries requiring uniform, high-frequency dielectric heating.
Related Standards
Organizations implementing EN IEC 61308:2026 should consider alignment with the following standards for comprehensive compliance and operational safety:
- IEC 60519-6:2022 - Safety in installations for electroheating and electromagnetic processing - Particular requirements for high-frequency dielectric and microwave heating and processing equipment.
- CISPR 11:2024 - Industrial, scientific and medical equipment - Radio-frequency disturbance characteristics - Limits and methods of measurement.
- IEC 60519-1:2020 - General requirements for industrial electroheating equipment.
- Relevant national or regional safety and EMC standards.
Practical Value
By providing unified, methodical test approaches for determining the power output of high-frequency dielectric heating installations, EN IEC 61308:2026 supports the industrial sector in achieving:
- Consistent product quality and processing results
- Greater energy efficiency and reduced operational costs
- Assurance of workplace safety and electromagnetic compatibility
- Trustworthy data for equipment selection, maintenance, and regulatory review
Proper adoption of this standard streamlines the assessment of high-frequency heater performance, aiding in international market access and fostering innovation in industrial electroheating processes.
Relations
- Effective Date
- 18-Feb-2025
- Effective Date
- 01-Sep-2026
- Effective Date
- 01-Sep-2026
- Effective Date
- 01-Sep-2026
Get Certified
Connect with accredited certification bodies for this standard
DVS-ZERT GmbH
German welding certification society.
CARES (UK Certification Authority for Reinforcing Steels)
UK certification for reinforcing steels and construction.
EWF/IIW (European/International Welding Federation)
International welding personnel certification.
Sponsored listings
Frequently Asked Questions
EN IEC 61308:2026 is a standard published by CLC. Its full title is "High-frequency dielectric heating installations - Test methods for the determination of power output". This standard covers: This document specifies test methods for the determination of useful high frequency power output in equipment for industrial heating and processing of materials. It is in particular applicable to HF generators made available to users as separate units. This document is basically applicable to equipment operating in the frequency range 100 kHz to 300 MHz, as defined in IEC 60519-1, with the following limitations. – This document does not apply to induction heating, which it is possible to carry out in the lower part of the specified frequency band. – The ISM centre frequencies for dielectric heating and processing of industrial interest are narrow bands about 6,78 MHz, 13,56 MHz, 27,12 MHz and 40,68 MHz. – This document is not applicable to: • appliances for household and similar use; • commercial use; • laboratory use; • medical high frequency equipment. For equipment working in designated ISM bands, it is a legal requirement that the frequency remains within the ISM bands according to CISPR 11, but the resonant frequency of the circuit varies with the change of dielectric parameters of the load. Therefore, the value of the mean output power in the work cycle can be much lower than the value obtained under the test conditions. This value depends upon the response of the tuning system. NOTE 1 The following criteria are suitable for determination of the classification as industrial equipment: – commercial equipment is typically designed and planned for series production of many identical units; – industrial equipment is typically produced in small series or even as single units; the processed goods are consumed or ready for final use at the end of the heating process. NOTE 2 Heating a workload with dielectric parameters which change significantly in time and/or with temperature, the value of the output power obtained with the actual charge can be different from that obtained with the test load specified in this document. This document relates to equipment normally operating under continuous rated conditions.
This document specifies test methods for the determination of useful high frequency power output in equipment for industrial heating and processing of materials. It is in particular applicable to HF generators made available to users as separate units. This document is basically applicable to equipment operating in the frequency range 100 kHz to 300 MHz, as defined in IEC 60519-1, with the following limitations. – This document does not apply to induction heating, which it is possible to carry out in the lower part of the specified frequency band. – The ISM centre frequencies for dielectric heating and processing of industrial interest are narrow bands about 6,78 MHz, 13,56 MHz, 27,12 MHz and 40,68 MHz. – This document is not applicable to: • appliances for household and similar use; • commercial use; • laboratory use; • medical high frequency equipment. For equipment working in designated ISM bands, it is a legal requirement that the frequency remains within the ISM bands according to CISPR 11, but the resonant frequency of the circuit varies with the change of dielectric parameters of the load. Therefore, the value of the mean output power in the work cycle can be much lower than the value obtained under the test conditions. This value depends upon the response of the tuning system. NOTE 1 The following criteria are suitable for determination of the classification as industrial equipment: – commercial equipment is typically designed and planned for series production of many identical units; – industrial equipment is typically produced in small series or even as single units; the processed goods are consumed or ready for final use at the end of the heating process. NOTE 2 Heating a workload with dielectric parameters which change significantly in time and/or with temperature, the value of the output power obtained with the actual charge can be different from that obtained with the test load specified in this document. This document relates to equipment normally operating under continuous rated conditions.
EN IEC 61308:2026 is classified under the following ICS (International Classification for Standards) categories: 25.180.10 - Electric furnaces. The ICS classification helps identify the subject area and facilitates finding related standards.
EN IEC 61308:2026 has the following relationships with other standards: It is inter standard links to EN 61308:2006, EN IEC 60519-6:2024, IEC 60050-841:2004, EN IEC 60519-1:2020. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN IEC 61308:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2026
Nadomešča:
SIST EN 61308:2006
Inštalacije za visokofrekvenčno dielektrično segrevanje - Preskusne metode za
ugotavljanje izhodne moči (IEC 61308:2026)
High-frequency dielectric heating installations - Test methods for the determination of
power output (IEC 61308:2026)
Hochfrequente dielektrische Erwärmungsanlagen - Prüfverfahren für die Bestimmung
der Ausgangsleistung (IEC 61308:2026)
Installations de chauffage diélectrique à haute fréquence - Méthodes d'essai pour la
détermination de la puissance de sortie (IEC 61308:2026)
Ta slovenski standard je istoveten z: EN IEC 61308:2026
ICS:
25.180.10 Električne peči Electric furnaces
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 61308
NORME EUROPÉENNE
EUROPÄISCHE NORM September 2026
ICS 25.180.10 Supersedes EN 61308:2006
English Version
High-frequency dielectric heating installations - Test methods for
the determination of power output
(IEC 61308:2026)
Installations de chauffage diélectrique à haute fréquence - Hochfrequente dielektrische Erwärmungsanlagen -
Méthodes d'essai pour la détermination de la puissance de Prüfverfahren für die Bestimmung der Ausgangsleistung
sortie (IEC 61308:2026)
(IEC 61308:2026)
This European Standard was approved by CENELEC on 2026-09-10. 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,
Türkiye 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
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61308:2026 E
European foreword
The text of document 27/1244/FDIS, future edition 3 of IEC 61308, prepared by TC 27 "Industrial
electroheating and electromagnetic processing" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN IEC 61308:2026.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2027-09-30
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-09-30
document have to be withdrawn
This document supersedes EN 61308:2006 and all of its amendments and corrigenda (if any).
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.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 61308:2026 was approved by CENELEC as a European
Standard without any modification.
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.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60050-841 - International Electrotechnical Vocabulary - - -
Part 841: Industrial electroheat
IEC 60519-1 - Safety in installations for electroheating EN IEC 60519-1 -
and electromagnetic processing - Part 1:
General requirements
IEC 60519-6 - Safety in installations for electroheating EN IEC 60519-6 -
and electromagnetic processing - Part 6:
Particular requirements for high frequency
dielectric and microwave heating and
processing equipment
IEC 61308 ®
Edition 3.0 2026-08
INTERNATIONAL
STANDARD
High-frequency dielectric heating installations - Test methods for the
determination of power output
ICS 25.180.10 ISBN 978-2-8327-1430-0
IEC 61308:2026-08(en)
IEC 61308:2026 © IEC 2026
CONTENTS
FOREWORD . 2
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 5
4 Test loads . 5
4.1 General . 5
4.2 Calorimetric load . 6
4.3 Lamp load . 6
4.4 Matched resistive load . 6
4.5 Wet-sand load. 6
5 Description of tests . 6
5.1 General . 6
5.2 Calorimetric load method . 6
5.3 Lamp-load temperature method . 9
5.4 Matched resistive load method . 11
5.5 Wet-sand load method . 11
5.6 Evaluation of the output power for high-frequency dielectric plastic welders . 12
5.6.1 General . 12
5.6.2 Test with plastic material . 12
5.7 Evaluation of the output power for type B equipment . 13
Annex A (informative) Recommended test circuit for the lamp-load method . 14
Figure 1 – Example of a calorimeter load . 8
Figure 2 – Example of a short tubular calorimeter load . 9
Figure 3 – Lamp-load circuit . 9
Figure 4 – Example of a lamp load . 10
Figure 5 – Detail of the lamp load . 11
Figure 6 – Plastic welding test electrode . 13
Figure A.1 – Recommended test circuit for the lamp-load method . 14
IEC 61308:2026 © IEC 2026
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
High-frequency dielectric heating installations -
Test methods for the determination of power output
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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 61308 has been prepared by IEC technical committee 27: Industrial electroheating and
electromagnetic processing. It is an International Standard.
This third edition cancels and replaces the second edition published in 2005. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) adaptation and alignment to the principles in more recent editions of IEC 60519-1 and
IEC 60519-6;
b) more detailed descriptions of, in particular, the calorimetric load test and output power
evaluation for dielectic plastic welders.
IEC 61308:2026 © IEC 2026
The text of this International Standard is based on the following documents:
Draft Report on voting
27/1244/FDIS 27/1248/RVD
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 International Standard is English.
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 www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/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, or
– revised.
IEC 61308:2026 © IEC 2026
1 Scope
This document specifies test methods for the determination of useful high frequency power
output in equipment for industrial heating and processing of materials. It is in particular
applicable to HF generators made available to users as separate units.
This document is basically applicable to equipment operating in the frequency range 100 kHz
to 300 MHz, as defined in IEC 60519-1, with the following limitations.
– This document does not apply to induction heating, which it is possible to carry out in the
lower part of the specified frequency band.
– The ISM centre frequencies for dielectric heating and processing of industrial interest are
narrow bands about 6,78 MHz, 13,56 MHz, 27,12 MHz and 40,68 MHz.
– This document is not applicable to:
• appliances for household and similar use;
• commercial use;
• laboratory use;
• medical high frequency equipment.
For equipment working in designated ISM bands, it is a legal requirement that the frequency
remains within the ISM bands according to CISPR 11, but the resonant frequency of the circuit
varies with the change of dielectric parameters of the load. Therefore, the value of the mean
output power in the work cycle can be much lower than the value obtained under the test
conditions. This value depends upon the response of the tuning system.
NOTE 1 The following criteria are suitable for determination of the classification as industrial equipment:
– commercial equipment is typically designed and planned for series production of many identical units;
– industrial equipment is typically produced in small series or even as single units; the processed goods are
consumed or ready for final use at the end of the heating process.
NOTE 2 Heating a workload with dielectric parameters which change significantly in time and/or with temperature,
the value of the output power obtained with the actual charge can be different from that obtained with the test load
specified in this document.
This document relates to equipment normally operating under continuous rated
...