SIST EN IEC 61307:2026

• Abstract:

  This document specifies test methods for the determination of the efficiency of frequency conversion from the electrical input, and of the available and workload microwave output power in industrial microwave heating installations, as well as operational flexibility.; This document is in principle applicable to industrial microwave heating equipment and installations in the frequency range from 300 MHz to 300 GHz but focussed on the microwave ISM frequencies below 6 GHz.; This document relates to industrial microwave heating equipment operating as intended by the manufacturer's specifications for normal operation.; This document does not apply to appliances for household and similar use (covered by IEC 60335-2-25 [1]1), commercial use (covered by IEC 60335-2-90 [2] and IEC 60335-2-110 [3]) or laboratory use (covered by IEC 61010-2-010 [4]).

• Status: Published
• Public Enquiry End Date: 31-Jul-2025
• Publication Date: 23-Sep-2026
• ICS: 25.180.10 - Electric furnaces
• Technical Committee: I09 - Imaginarni 09
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 22-Sep-2026
• Due Date: 27-Nov-2026
• Completion Date: 24-Sep-2026
• Ref Project: EN IEC 61307:2026 - Industrial microwave heating installations - Test methods for the determination of power output

• Replaces: SIST EN 61307:2011 - Industrial microwave heating installations - Test methods for the determination of power output
• Effective Date: 01-Nov-2026
• Refers: SIST EN IEC 60519-6:2024 - Safety in installations for electroheating and electromagnetic processing - Part 6: Particular requirements for high frequency dielectric and microwave heating and processing equipment (IEC 60519-6:2022)
• Effective Date: 15-Sep-2026

SIST EN IEC 61307:2026 is the Slovenian adoption of EN IEC 61307:2026, based on IEC 61307:2026, for industrial microwave heating installations. It specifies test methods for determining available and workload microwave output power, electrical conversion efficiency, and operational flexibility. Engineers, quality teams, and buyers use it to compare equipment and to specify how power measurements are to be made under normal intended operation.

What does SIST EN IEC 61307:2026 specify?

SIST EN IEC 61307:2026 specifies test methods for industrial microwave heating installations operating as intended by the manufacturer. It applies in principle across 300 MHz to 300 GHz, but the focus is on microwave ISM frequencies below 6 GHz.

The document is organized into:

• Clause 1 Scope
• Clause 2 Normative references
• Clause 3 Terms and definitions
• Clause 4 Methods of microwave power measurements
• Clause 5 Calorimetric power measurements of available microwave power
• Clause 6 Dummy load power measurements
• Clause 7 Determination of effective microwave power with individual load items
• Clause 8 Electrical efficiency
• Clause 9 Cold start, standby and holding power consumption
• Annex A informative equipment class

Annex	What it covers
Annex A	Equipment class, including Type A equipment and Type B equipment

The scope excludes appliances for household and similar use, commercial use, and laboratory use. In practice, that keeps the document aimed at industrial heating installations, not domestic ovens, commercial microwave appliances, or laboratory heating equipment.

What are the key requirements of SIST EN IEC 61307:2026?

SIST EN IEC 61307:2026 sets out several alternative measurement routes, and the correct choice depends on the equipment layout, frequency, power level, and workload. The key practical point is that the document does not use one single power test for every installation - it provides different methods for different industrial cases.

Clause 4 - choose the right power measurement route

Clause 4 states that tests shall be carried out within intended operation. It distinguishes between available microwave power output, workload power, and effective microwave power.

For a reader, this means the first task is to identify what is being measured:

• available microwave power output from the generator
• power delivered to the normal workload
• effective microwave power for more practical load conditions

Clause 4 also distinguishes Type A equipment from Type B equipment. Type A has a separable microwave generator and applicator, while Type B has the generator directly coupled to the applicator. This matters because Type A allows more direct investigation of system properties.

Clause 5 - use calorimetry for available microwave power

Clause 5 covers calorimetric measurements of available microwave power, mainly with water as the absorbing medium. The direct liquid water method in 5.2 uses water flow and temperature rise to calculate output power.

In practice, this means the test lab needs stable flow, accurate temperature measurement, and controlled inlet and outlet conditions. The document also states that the measurement inaccuracy should be less than 5%, so instrumentation quality matters. Clause 5.3 gives a different route for drying substitute loads when the process is more dynamic and simple water calorimetry is not representative.

Clause 6 - use dummy loads for special cases

Clause 6 defines a dummy load method for cases where practical workloads would reduce accuracy. The dummy load is an artificial item with known thermal properties, and it may also use internal field strength measurement.

This is useful when a buyer or test lab wants a cleaner power characterization of the generator assembly. The document again calls for high-accuracy instruments and less than 5% measurement inaccuracy.

Clause 7 - measure effective microwave power with realistic loads

Clause 7 applies when the normal load is hard to specify, consists of individual items, or is not suitable for Clause 5 methods. It uses an artificial load that behaves similarly to the real workload.

The practical value of Clause 7 is that it ties the test more closely to real processing. Clause 7.1 requires the estimated inaccuracy to be stated with the result, and it says the reflected-power deviation used for comparison should not exceed 10% of transmitted power unless the load is especially difficult to characterize. Clause 7.2 gives an open container water test, and Clause 7.3 covers drying workloads for stationary continuous drying processes.

Clause 8 - measure electrical efficiency from input to microwave output

Clause 8 defines electrical conversion efficiency as the relationship between available microwave power output and electrical input to the mains frequency power supply or microwave generator assembly. Clause 8.3 lists the electrical circuits that belong in the input measurement, including the main power circuit, cathode filament heating circuit, immediate generator circuits, control circuits, and additional electric consumers such as pumps and fans.

In practice, this clause matters when comparing equipment on energy use, because it tells the tester what to count as part of the input and what to record separately.

Clause 9 - record start-up, standby, and holding consumption

Clause 9 extends the power assessment to operating states that matter in real production. It covers cold start-up, standby operation, hot standby operation, and holding state.

For users, this means energy performance is not only about active microwave output. The document requires measurement of start-up time and energy, standby power, possible hibernation mode, and holding-state energy and time. That is important when the equipment spends a lot of time waiting between batches or maintaining product temperature.

What terms does SIST EN IEC 61307:2026 define?

• microwave heating equipment - An assembly of electrical and mechanical devices that transfers microwave energy to the workload, usually including the generator, cooling, applicator or cavity, cabling, control circuitry, and transport means if used.
• equipment class - A group within a type of equipment that uses the same processing principle for the workload, either Type A or Type B.
• Type A equipment - Equipment where the microwave generator is independent of, or separable from, the applicator receiving the power.
• Type B equipment - Equipment where the microwave generator is directly coupled to the applicator, with no transmission line between them.
• electrical conversion efficiency - The ratio between available microwave power output and the electrical input to the mains frequency power supply or microwave generator assembly.
• overall efficiency - The efficiency of the complete system, including ancillary power consumption except workload transport.
• microwave workload - The object being treated by microwaves, including any container or holder that is part of the processing.
• standby operation - A zero-output state between periods of intended power operation, allowing immediate return to full power.

Who uses SIST EN IEC 61307:2026?

SIST EN IEC 61307:2026 is used by manufacturers of industrial microwave heating equipment, test laboratories, and technical teams responsible for product verification. It is also relevant to quality managers and buyers who need a clear basis for comparing output power, efficiency, and operating modes.

It is especially useful in industries that use industrial electroheating and electromagnetic processing, including drying, heating, and related microwave processing applications. It helps teams decide how to measure power, how to document test conditions, and how to compare equipment classes and load types.

What changed in SIST EN IEC 61307:2026 from the previous edition?

SIST EN IEC 61307:2026 replaces SIST EN 61307:2011 and is identified as a technical revision. The stated changes are:

• coverage now includes start-up, standby, and holding power consumption
• coverage now includes hibernation mode and other aspects of operational flexibility
• the descriptions of microwave power aspects are more detailed
• handling of Type A and Type B equipment is more detailed

Which standards are used with SIST EN IEC 61307:2026?

Standard	What it contributes
IEC 60050-841	Terminology from the International Electrotechnical Vocabulary for industrial electroheat
IEC 60519-6	Safety requirements for high frequency dielectric and microwave heating and processing equipment
IEC 60335-2-25	Cited for household and similar use, which is outside the scope
IEC 60335-2-90	Cited for commercial microwave ovens, which are outside the scope
IEC 60335-2-110	Cited for commercial microwave appliances with insertion or contacting applicators, which are outside the scope
IEC 61010-2-010	Cited for laboratory heating equipment, which is outside the scope
IEC 60705	A comparison point for microwave oven performance measurement in the notes

What does the SIST EN IEC 61307:2026 document contain?

The document contains measurement methods, definitions, and operating-state test guidance rather than product design requirements. Clause 5 gives a calorimetric formula for available microwave power, and Clause 7 describes how to assess effective power with realistic or substitute loads.

It also contains practical test conditions such as water flow, temperature rise, load arrangement, and accuracy targets. Annex A adds an informative classification of equipment type, with figures for Type A and Type B equipment, which helps users identify which test route fits their installation.

SLOVENSKI STANDARD
01-november-2026
Nadomešča:
SIST EN 61307:2011
Industrijske inštalacije za mikrovalovno segrevanje - Preskusne metode za
ugotavljanje izhodne moči (IEC 61307:2026)
Industrial microwave heating installations - Test methods for the determination of power
output (IEC 61307:2026)
Industrielle Mikrowellen-Erwärmungsanlagen - Messverfahren für die Bestimmung der
Ausgangsleistung (IEC 61307:2026)
Installations industrielles de chauffage par micro-ondes - Méthodes d'essai pour la
détermination de la puissance de sortie (IEC 61307:2026)
Ta slovenski standard je istoveten z: EN IEC 61307:2026
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 61307

NORME EUROPÉENNE
EUROPÄISCHE NORM September 2026
ICS 25.180.10 Supersedes EN 61307:2011
English Version
Industrial microwave heating installations - Test methods for the
determination of power output
(IEC 61307:2026)
Installations industrielles de chauffage par micro-ondes - Industrielle Mikrowellen-Erwärmungsanlagen -
Méthodes d'essai pour la détermination de la puissance de Messverfahren für die Bestimmung der Ausgangsleistung
sortie (IEC 61307:2026)
(IEC 61307:2026)
This European Standard was approved by CENELEC on 2026-09-09. 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 61307:2026 E
European foreword
The text of document 27/1243/FDIS, future edition 4 of IEC 61307, prepared by TC 27 "Industrial
electroheating and electromagnetic processing" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN IEC 61307:2026.
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 61307:2011 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 61307:2026 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standard indicated:
IEC 60335-2-25 NOTE Approved as EN IEC 60335-2-25
IEC 60335-2-90 NOTE Approved as EN IEC 60335-2-90
IEC 60335-2-110 NOTE Approved as EN IEC 60335-2-110
IEC 61010-2-010 NOTE Approved as EN IEC 61010-2-010
IEC 60705 NOTE Approved as EN IEC 60705
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 60519-6 - 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 61307 ®
Edition 4.0 2026-08
INTERNATIONAL
STANDARD
Industrial microwave heating installations - Test methods for the determination
of power output
ICS 25.180.10  ISBN 978-2-8327-1429-4

IEC 61307:2026-08(en)
IEC 61307:2026 © IEC 2026
CONTENTS
FOREWORD . 2
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Methods of microwave power measurements . 8
4.1 General . 8
4.2 Workload power . 8
4.3 Effective microwave power and efficiency . 9
5 Calorimetric power measurements of available microwave power . 9
5.1 General . 9
5.2 Direct liquid water power measurements . 9
5.3 Drying of substitute loads . 10
6 Dummy load power measurements . 10
7 Determination of effective microwave power with individual load items . 11
7.1 General . 11
7.2 Open container water test . 11
7.3 Tests with drying workload . 12
8 Electrical efficiency . 12
8.1 General . 12
8.2 Available microwave power output . 12
8.3 Electrical input . 12
9 Cold start, standby and holding power consumption . 13
9.1 General . 13
9.2 Some aspects . 13
Annex A (informative) Equipment class . 14
Bibliography . 15

Figure A.1 – Type A equipment . 14
Figure A.2 – Type B equipment . 14

IEC 61307:2026 © IEC 2026
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Industrial microwave heating installations -
Test methods for the determination of power output

FOREWORD
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all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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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 61307 has been prepared by IEC technical committee 27: Industrial electroheating and
electromagnetic processing. It is an International Standard.
This fourth edition cancels and replaces the third edition published in 2011. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) it covers not only the standby and hibernation modes, but also start-up, standby and holding
power consumption, as well as other aspects of operation flexibility;
b) more detailed descriptions of the aspects of microwave power, and handling of the A and B
types of equipment.
IEC 61307:2026 © IEC 2026
The text of this International Standard is based on the following documents:
Draft Report on voting
27/1243/FDIS 27/1247/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 61307:2026 © IEC 2026
1 Scope
This document specifies test methods for the determination of the efficiency of frequency
conversion from the electrical input, and of the available and workload microwave output power
in industrial microwave heating installations, as well as operational flexibility.
This document is in principle applicable to industrial microwave heating equipment and
installations in the frequency range from 300 MHz to 300 GHz but focussed on the microwave
ISM frequencies below 6 GHz.
This document relates to industrial microwave heating equipment operating as intended by the
manufacturer's specifications for normal operation.
This document does not apply to appliances for household and similar use (covered by
IEC 60335-2-25 [1] ), commercial use (covered by IEC 60335-2-90 [2] and IEC 60335-2-110 [3])
or laboratory use (covered by IEC 61010-2-010 [4]).
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.
IEC 60050-841, International Electrotechnical Vocabulary (IEV) - Part 841: Industrial
electroheat
IEC 60519-6, Safety in installations for electroheating and electromagnetic processing - Part 6:
Particular requirements for high frequency dielectric and microwave heating and processing
equipment
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60519-6,
IEC 60050-841 and the following apply.
ISO and IEC maintain terminology 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
3.1
microwave heating equipment
assembly of electrical and mechanical devices intended for the transfer of microwave energy to
the workload and comprising, in general, power supplies, microwave generators or microwave
generator assemblies with cooling arrangements and circulators if used, microwave applicators
or cavities with ventilation arrangements if used, interconnecting cables and waveguides,
control circuitry, and means for transporting the workload if used
___________
Numbers in square brackets refer to the Bibliography.
IEC 61307:2026 © IEC 2026
3.2
equipment class
group within a type of equipment, using the same principle for processing of the workload either
type A or type B
SEE: Annex A.
Note 1 to entry: An example of type is microwave equipment, and a class example is such equipment for wood
drying heating in a specified capacity interval using the ISM frequency 2,45 GHz.
3.3
type A equipment
equipment with the microwave generator (frequency converter part) independent
of, or separable from, the applicator to which the microwave power is provided
EXAMPLE A coaxial feeder, a waveguide junction.
Note 1 to entry: This allows the integration of a circulator as protection for the magnetron against reflected
microwave power as well as a tuner to minimize microwave reflection for proper tuning/matching.
Note 2 to entry: Any ancillary microwave generator components such as cathode heater transformers and the
generator cooling system are also separable.
3.4
type B equipment
equipment with the microwave generator (frequency converter part) being directly
coupled to the applicator, without a transmission line in between
3.5
electrical conversion efficiency of microwave heating equipment
quotient between the available microwave power output and the electrical input to the mains
frequency power supply or microwave generator assembly, at power settings for intended
operation
3.6
overall efficiency
efficiency of the complete system including all ancillary power consumption except for workload
transport
EXAMPLE Cooling fans or pumps and other cooling systems.
3.7
microwave generator
source used to produce electromagnetic energy in the frequency range from 300 MHz to
300 GHz
Note 1 to entry: In the context of this document, the microwave generator is only the component where the
frequency conversion takes place.
3.8
microwave generator assembly
part of the microwave heating equipment comprising an apparatus producing microwave energy
and its associated transmission line output port
Note 1 to entry: The assembly includes the microwave generator, the power supply of the microwave generator and
its ancillary and control circuits. If a circulator is used, it is also included.
Note 2 to entry: Microwave heating equipment containing a microwave generator assembly was classified as type
A in earlier editions of IEC 61307; equipment where a transmission line output port is not available was classified as
type B.
3.9
microwave applicator
structure which applies the microwave energy to the load
IEC 61307:2026 © IEC 2026
3.10
microwave cavity
space enclosed by inner metal walls and a door or an access opening and in which the
microwave load is placed
3.11
microwave enclosure
structure which is intended to confine the microwave energy to a defined region
EXAMPLE A cavity, door seals and waveguides.
3.12
microwave workload
object to be treated by microwaves
Note 1 to entry: The workload includes any container, holder or other device necessary for the processing and
which is directly or indirectly subjected to the output power. The processed object/material as such is also called the
load.
3.13
normal load
nominal microwave workload at full rated microwave output power as specified by the
manufacturer's documentation
3.14
normal operation
equipment operation under normal load conditions under nominal ambient conditions including
the nominal electrical supply network
3.15
intended operation
range of microwave output and allowable electrical input conditions, for intended workloads as
specified by the manufacturer
Note 1 to entry: Several setting combinations are typically specified.
3.16
performance
degree to which the intended functions, including energy or
power consumption and output as well as the result of the treatment of the workload are
accomplished
3.17
equipment capacity
measure of the production rate capability of equipment when in intended normal operation
EXAMPLE Flow, mass or volume.
Note 1 to entry: The equipment capacity does not refer to the volume of the available cavity space.
3.18
cold start-up
process by which the equipment is energised into hot standby operation from the cold state,
including all other start-up operations which enable the equipment to run under intended
operation
Note 1 to entry: This mode of operation applies to cases where there is a significant energy consumption needed
for obtaining a state of the equipment allowing the actual processing of the workload.
IEC 61307
...