SIST EN ISO 17662:2025

SLOVENSKI STANDARD
01-november-2025
Nadomešča:
SIST EN ISO 17662:2016
Varjenje - Umerjanje, preverjanje in validacija opreme, ki se uporablja za varjenje,
vključno s pomožnimi dejavnostmi (ISO 17662:2025)
Welding - Calibration, verification and validation of equipment used for welding, including
ancillary activities (ISO 17662:2025)
Schweißen - Kalibrierung, Verifizierung und Validierung von Einrichtungen einschließlich
ergänzender Tätigkeiten, die beim Schweißen verwendet werden (ISO 17662:2025)
Soudage - Étalonnage, vérification et validation du matériel utilisé pour le soudage, y
compris pour les procédés connexes (ISO 17662:2025)
Ta slovenski standard je istoveten z: EN ISO 17662:2025
ICS:
25.160.30 Varilna oprema Welding equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 17662
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2025
EUROPÄISCHE NORM
ICS 25.160.30 Supersedes EN ISO 17662:2016
English Version
Welding - Calibration, verification and validation of
equipment used for welding, including ancillary activities
(ISO 17662:2025)
Soudage - Étalonnage, vérification et validation du Schweißen - Kalibrierung, Verifizierung und
matériel utilisé pour le soudage, y compris pour les Validierung von Einrichtungen einschließlich
procédés connexes (ISO 17662:2025) ergänzender Tätigkeiten, die beim Schweißen
verwendet werden (ISO 17662:2025)
This European Standard was approved by CEN on 12 September 2025.

CEN 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 CEN
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 CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 17662:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 17662:2025) has been prepared by Technical Committee ISO/TC 44 "Welding
and allied processes" in collaboration with Technical Committee CEN/TC 121 “Welding and allied
processes” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2026, and conflicting national standards shall
be withdrawn at the latest by March 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 17662:2016.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 17662:2025 has been approved by CEN as EN ISO 17662:2025 without any modification.

International
Standard
ISO 17662
Third edition
Welding — Calibration, verification
2025-09
and validation of equipment used
for welding, including ancillary
activities
Soudage — Étalonnage, vérification et validation du matériel
utilisé pour le soudage, y compris pour les procédés connexes
Reference number
ISO 17662:2025(en) © ISO 2025
ISO 17662:2025(en)
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 17662:2025(en)
Contents Page
Foreword .iv
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4 General requirements . 3
4.1 General .3
4.2 Frequency .4
4.3 Requirements .4
4.4 Process data .5
4.5 Material properties .5
5  Process data common to more than one welding/brazing process . 5
5.1 Process data common to all welding/brazing processes .5
5.2 Requirements specific to several welding/brazing processes .7
5.3 Requirements specific to arc welding (group 1) .7
6  Metal arc welding without gas protection (group 11) . 9
7  Plasma arc welding (group 15) . 9
8  Resistance welding (groups 21, 22, 23, 24, and 25) .10
9 Gas welding (group 3) .11
10  Friction welding (group 42) .11
11 Laser beam welding (group 52) .12
12  Electron beam welding (group 51) .13
13 Stud welding (group 78) . 14
14  Brazing and soldering (group 9) . .15
14.1 General . 15
14.2 Manual and mechanized flame brazing (group 912) .16
14.3 Induction brazing (group 916) .16
14.4 Resistance brazing (group 918) .16
14.5 Furnace brazing in protective atmosphere (group 921) .17
14.6 Vacuum brazing (group 922) .18
14.7 Furnace brazing in open atmosphere (group 921) .19
14.8 Dip-bath brazing (group 923), salt-bath brazing (group 924) and flux-bath brazing
(group 925) . 20
14.9 Infrared soldering (group 941) . 20
15  Preheat and/or post weld heat treatment .21
15.1 Preheat .21
15.2 Post weld heat treatment .21
16  Post weld cleaning .22
17  Flame cutting (group 81) and other ancillary processes .22
Annex A (informative) Details for stud welding .23
Annex B (informative)  Acceptance testing of equipment .26
Annex C (informative) Parties involved .27
Bibliography .28

iii
ISO 17662:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO 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, ISO 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
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 44, Welding and allied processes, Subcommittee
SC 10, Quality management in the field of welding, in collaboration with the European Committee for
Standardization (CEN) Technical Committee CEN/TC 121, Welding and allied processes, in accordance with
the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 17662:2016), which has been technically
revised.
The main changes are as follows:
— Clause 13 (Stud welding) technically revised;
— Clause 14 (Brazing) soldering added;
— bibliography updated.
Any feedback or questions on this document should be directed to the user’s
national standards body. A complete listing of these bodies can be found at
www.iso.org/members.html. Official interpretations of ISO/TC 44 documents, where they exist, are
available from this page: https://committee.iso.org/sites/tc44/home/interpretation.html.

iv
International Standard ISO 17662:2025(en)
Welding — Calibration, verification and validation of
equipment used for welding, including ancillary activities
1  Scope
This document specifies requirements for calibration, verification and validation of equipment used for:
— control of process variables during fabrication,
— control of the properties of equipment used for welding or welding allied processes,
where the resulting output cannot be readily or economically documented by subsequent monitoring,
inspection and testing. This involves process variables influencing the fitness-for-purpose and in particular
the safety of the fabricated product.
NOTE This document is based on the lists of process variables stated in International Standards for specification
of welding procedures, in particular, but not exclusively in the ISO 15609 series. Future revisions of these International
Standards can result in addition or deletion of parameters considered necessary to specify.
Some guidance is, in addition, given in Annex B for requirements for calibration, verification and validation
as part of acceptance testing of equipment used for welding or allied processes.
This document does not specify requirements to calibrate, verify and validate as part of inspection, testing,
non-destructive testing or measuring of final welded products performed in order to verify product
conformance.
This document applies only to calibration, verification and validation of equipment for use in production or
on site.
This document does not apply to the manufacture and installation of equipment for welding. Requirements
for new equipment are formulated in directives and product codes (standards), as necessary.
Annex C provides information when other parties are involved in calibration, verification and validation
activities.
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.
ISO 669, Resistance welding — Resistance welding equipment — Mechanical and electrical requirements
ISO 5171, Gas welding equipment — Pressure gauges used in welding, cutting and allied processes
ISO 5826, Resistance welding equipment — Transformers — General specifications applicable to all transformers
3  Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp

ISO 17662:2025(en)
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
accuracy class
class of measuring instruments or measuring systems that meets stated metrological requirements that are
intended to keep measurement errors or instrumental measurement uncertainties within specified limits
under specified operating conditions
[SOURCE: ISO/IEC Guide 99:2007, 4.25]
3.2
accuracy
closeness of agreement between a measured quantity value and a true quantity value of a measurand
Note 1 to entry: The term measurand is defined by the VIM (ISO/IEC Guide 99:2007, 2.3) as a “quantity intended to be
measured”.
3.3
calibration
set of operations that establish, under specified conditions, the relationship between values of quantities
indicated by a measuring instrument or measuring system, or values represented by a material measure or
a reference material, and the corresponding values realized by measurement standards
Note 1 to entry: The term “material measure” means a device intended to reproduce or supply, in a permanent manner
during its use, one or more known values of a given quantity.
3.4
measurement
process of experimentally obtaining one or more quantity values that can reasonably be attributed to a
quantity
[SOURCE: ISO/IEC Guide 99:2007, 2.1]
3.5
measuring instrument
device used for making measurements, alone or in conjunction with one or more supplementary devices
[SOURCE: ISO/IEC Guide 99:2007, 3.1]
3.6
measuring system
set of one or more measuring instruments (3.5) and often other devices, including any reagent and supply,
assembled and adopted to give information used to generate measured quantity values within specified
intervals for quantities of specified kinds
[SOURCE: ISO/IEC Guide 99:2007, 3.2]
3.7
repeatability
closeness of the agreement between the results of successive measurements of
the same measurement carried out under the same conditions of measurement
3.8
traceability
property of the result of a measurement or the value of a standard whereby it can be related to stated
references, usually national or international standards, through an unbroken chain of comparisons all
having stated uncertainties
3.9
validation
confirmation through the provision of objective evidence that the requirements for a specific intended use
(e.g. client specification) or application (e.g. product standard) have been fulfilled

ISO 17662:2025(en)
3.10
verification
confirmation through the provision of objective evidence that specified requirements have been fulfilled
Note 1 to entry: Verification is also interpreted as a confirmation that an available process achieved an expected level
of success.
4 General requirements
4.1 General
Measuring, inspection and test equipment are used for many purposes and as part of many work operations
during welding fabrication. However, the purposes can be grouped as follows:
a) demonstration of conformance of a product to specified requirements;
b) control of processes where the resulting output cannot be readily or economically verified by subsequent
monitoring, inspection and testing;
c) general process control.
Measuring, inspection and test equipment used for demonstration of conformance of product to specified
requirements (4.1 a)) should be properly calibrated, verified, or validated. This is, for example, required
in ISO 9001. Many of the procedures used for demonstration of conformance inspection are covered by
standards, which typically include provisions for calibration, verification, or validation. This is, for example,
the case for standards for non-destructive testing and/or destructive testing of welds. Further, requirements
for documentation of such quality characteristics (e.g. non-destructive testing) are stated in application
standards and/or contracts. Calibration, verification and validation of measuring devices used for this
category of application are not covered by this standard, apart from a few comments on welding inspection
and visual examination. The relevant standards for inspection and testing shall be consulted.
However, some quality characteristics (also related to safety) cannot be inspected or tested on the finished
structure or product. This is, for example, the case for the materials properties of weld metals and to the
heat-affected zones adjacent to welds. Such quality characteristics shall be documented indirectly by proper
documentation of the fabrication process (4.1 b)). The guidance given in this standard is limited mainly to
calibration, verification and validation of measuring devices used for such indirect documentation of quality
characteristics, influenced by welding. The measuring, inspection and test equipment can be separate
measuring instruments or built-in instruments in, for example, the power sources used for welding.
Measuring, inspection and test equipment used for general process control can also need to be calibrated,
1)
verified or validated (4.1 c)). This is, for example, recommended in ISO 9004 . However, specifications
of such requirements are left entirely to the discretion of the manufacturer, the requirements cannot be
standardized and they are not covered by this document.
A key issue of this document is discussion of the influence of various process variables on the resulting output
and in particular of the possibilities for verification of the output by subsequent monitoring, inspection and
testing. The distinction between process variables in group (4.1 b)) and group (4.1 c)) is not always easy but
essential for the interpretation of contractual and/or legal requirements. The main basis for selection of the
relevant variables is the standards for specification of welding procedures.
The specific requirements for calibration, verification and validation of a particular instrument shall be
derived from the required performance and shall be compatible with the permissible range as specified in
the welding procedure specification (WPS) for the variable(s) in question. Many types of instruments used
for control of welding, such as ammeters, voltmeters, thermocouples, stopwatches, are also used for non-
welding purposes. It should be noted that the requirements to accuracy, when used for welding purposes
can be less stringent than for other applications of the instruments. “Normal” (standardized) procedures
for calibration, verification and validation of the instruments can be too stringent and costly, if applied for
welding purposes.
1) Note that ISO 9004 is not intended for certification, regulatory or contractual use.

ISO 17662:2025(en)
The formal requirements to calibration, verification and validation as regards control of welding and allied
processes are specified in the ISO 3834 series and the ISO 14554 series. Some more specific supplementary
requirements can, however, be found in structural codes and/or as contractual requirements.
4.2  Frequency
When a need for calibration, verification, or validation of equipment has been identified then calibration,
verification, or validation shall be carried out once a year, unless otherwise specified. Where there is a
proven record of repeatability and reliability the frequency of calibration, verification and validation can
be reduced. It can, however, be necessary to re-calibrate, re-verify or re-validate at more frequent intervals,
depending upon the recommendation of the manufacturer of the instrument, the requirements of the user,
or where there is reason to believe that the performances of the equipment have deteriorated. Equipment
shall be isolated and calibration, verification, or validation carried out before the equipment is put back in
use after the following cases:
— whenever there are indications that an instrument does not register properly;
— whenever the equipment has been visibly damaged and the damage can have influenced the function of
one or more instruments;
— whenever the equipment has been misused, subject to severe stress (overloads, etc.), or subject to any
other event which can have resulted in damage to one or more instrument;
— whenever the equipment has been rebuilt or repaired.
4.3 Requirements
Calibration, verification and validation shall be carried out for all the instruments used for control of
the welding process variables specified in the welding/brazing procedure specification. International
Standards for specification of welding/brazing procedures provide comprehensive lists of variables, but not
all variables are essential for all applications. The following are some guidelines on relevant requirements
for all common welding/brazing processes.
Calibration, verification and validation may be omitted entirely in the following cases.
a) When verification of the process is not required.
Calibration, verification and validation may be omitted for all processes where there is no legal or
contractual requirement for verification or validation of the process.
NOTE 1 This is usually the case for processes such as flame or plasma cutting and air arc gouging.
b) Mass production.
Calibration, verification and validation may be omitted, provided all the following conditions are
fulfilled:
— the production is controlled by pre-production testing, followed by testing of samples from the
actual production at regular intervals;
— the control is supported by an adequate system for statistical quality control;
— the process is reasonably stable during the interval between testing of samples;
— pre-production testing and sampling are performed separately for each production line (welding cell).
c) Series and single piece production.
Calibration, verification and validation may be omitted, provided all the following conditions are
fulfilled:
— the procedures are approved by procedure testing;

ISO 17662:2025(en)
— the actual production is carried out by the same welding machine used during procedure testing;
or the process is supported by a calibrated online-monitoring system for welding parameters.
NOTE 2 The manufacturer can, for managerial reasons, decide to perform much more comprehensive
calibration, verification and validation. The main reasons are the following:
— more efficient control of processes resulting in higher productivity and more economical operation;
— possibility of transferring procedures from one equipment to another without adjustments, maintaining an
uninterrupted production;
— higher process stability and therefore increased economic efficiency;
— control data becomes compatible with different types of equipment.
4.4  Process data
For all welding/brazing processes, process data where calibration, verification, or validation are needed are
stated in Clause 5. Calibration, verification, or validation is not needed for all other process data.
4.5 Material properties
Several kinds of materials are used in connection with production involving welding or ancillary activities.
This includes parent metals and filler metals but also shielding gases, materials used for backing, etc.
Occasionally, incoming inspection and testing or check of stored materials can be performed, e.g. in order
to identify a material. Such activities involve instruments and procedures for chemical analysis, positive
material identification, etc. Provisions for calibration of instruments used for such purposes are outside the
scope of this document.
NOTE Purity of gases can be measured prior to welding, however, this is an exception.
5  Process data common to more than one welding/brazing process
5.1  Process data common to all welding/brazing processes
The International Standards for specification of welding procedures require some data, which are common
to all welding processes. Calibration, verification, or validation requirements are detailed in Tables 1 to 8.
Table 1 — Related to the parent material and filler metals
Designation Need for calibration, verification, or vali- Instruments and techniques
dation
Material dimension Instruments used for measurement and/ Measuring instruments such as vernier cal-
or verification of material dimensions shall lipers, micrometer callipers, gauge blocks,
be calibrated, as necessary. Requirements rulers and straightedges, etc. are covered by
depend on the specified tolerances, etc. several EN-, ISO- and national standards.

ISO 17662:2025(en)
Table 2 — Related to the joint
Designation Need for calibration, verification, or  Instruments and techniques
validation
Joint design Instruments used for measurement and/ See ISO 17637.
or verification of joint dimension shall be
validated.
Welding position Requirements for determination of See ISO 6947.
welding position are, as a general rule,
not very exacting. Instruments used
for measurement and/or verification of
welding position (e.g. spirit levels and
instruments used for measurements
of angles) do not have to be calibrated,
verified or validated unless damaged, and
after having been repaired.
Joint preparation Instruments used for measurement and/ See ISO 17637.
or verification of joint dimension and
outline shall be validated.
Table 3 — Welding equipment
Designation Need for calibration, verification, or  Instruments and techniques
validation
Characteristic dimensions, Instruments used for measurement and/ Measuring instruments such as vernier
shape and configuration or verification of dimensions, shape, po- callipers, micrometer callipers, gauge
of welding equipment and sition, etc. shall be calibrated, verified or blocks, rulers and straightedges, etc. are
working conditions such as the validated, as appropriate. covered by several EN-, ISO- and nation-
following: al standards.
—  number and configuration
of wire electrodes;
—  diameter of shielding gas
nozzles and fixtures;
—  distance contact tip nozzle
to the surface of the workpiece;
—  diameter of electrodes and
wire electrodes;
—  dimensions, shape, po-
sition, etc. of back and front
support.
Table 4 — Jigs, fixtures and tooling
Designation Need for calibration, verification, or  Instruments and techniques
validation
Jigs and fixtures Instruments used for measurement and/ Measuring instruments such as vernier
or verification of dimensions, shape, callipers, micrometer callipers, gauge
position, etc. of jigs, fixtures and tooling blocks, rulers and straightedges, etc.
shall be calibrated, verified or validated, are covered by several EN-, ISO- and
as appropriate. national standards.
Manipulators, Instruments used for control of move- ISO 14744-5 and ISO 15616-2 may be
ments shall be calibrated, verified or used for general guidance (although the
x-y tables, etc.
validated, as appropriate. application is formally limited to beam
welding).
ISO 17662:2025(en)
Table 5 — Pre-welding cleaning
Designation Need for calibration, verification, or  Instruments and techniques
validation
Surface conditions Instruments used for control of surface Specific to instrument and surface char-
conditions shall be validated. acteristics. Appropriate standards for
the equipment shall be consulted.
Practice Instruments used for process control Appropriate standards for the equip-
shall be calibrated, verified or validated, ment shall be consulted.
as appropriate, depending on the nature
of the cleaning practice: Washing, pick-
ling, abrasive blasting, etc.
5.2  Requirements specific to several welding/brazing processes
Table 6 — Gas backing
Designation Need for calibration, verification, or  Instruments and techniques
validation
Gas flow rate Instruments shall be validated. Required Validated against master instrument.
accuracy ±20 % of gas flow rate.
Gas backing purity (oxygen Instruments shall be validated. Required Calibration by reference gases of known
content) accuracy is ±25 % of actual value. How- composition, covering at least the in-
ever, the purity can also be controlled by terval from 10 ppm to 30 ppm for argon
inspection of colour of protected side of and 50 ppm to 150 ppm for forming gas.
weld in the area where heat can have an
influence of the surface.
Table 7 — Consumables
Designation Need for calibration, verification, or  Instruments and techniques
validation
Condition of storage Instruments used, for example, for con- Appropriate standards for the equip-
trol of storage conditions (temperature, ment shall be consulted. Validated
humidity, etc.), shall be calibrated, veri- against master instrument.
fied or validated. Requirements: ±5 % for
the instruments concerning humidity and
±5 °C for thermometer.
Baking oven, holding oven and Instruments for temperature control. Appropriate standards for the equip-
quiver Thermometers and other temperature in- ment shall be consulted.
dicators shall be validated. Requirement:
max. ±10 °C.
Treatment prior to welding/ Instruments used for process control Appropriate standards for the equip-
brazing shall be calibrated, verified or validated, ment shall be consulted.
as appropriate, depending on the nature
of the treatment: Drying, cleaning, etc.
Table 8 — Shielding gases
Designation Need for calibration, verification, or  Instruments and techniques
validation
Shielding gas flow Flow meters shall be validated. Require- Appropriate standards for the equip-
ment max. ±20 % of actual value. ment shall be consulted.
5.3  Requirements specific to arc welding (group 1)
During arc welding, it is not possible for the welder to observe any measuring instrument and they often weld
by observations performed by “sound”, using their experience. The welding process is visually controled.
This skill shall be verified through qualification testing of the welders for the used welding process.

ISO 17662:2025(en)
Heat input is controlled by check of run-out-lengths and/or weld run cross section (see ISO/TR 18491).
Where heat input is an essential variable, all instruments used shall be calibrated, verified or validated.
Provisions for specification of welding procedures are given in ISO 15609-1. Calibration, verification, or
validation can be needed for the welding data stated in Table 9 to Table 12.
Table 9 — Weaving for manual arc welding (if applied)
Designation Need for calibration, verification, or  Instruments and techniques
validation
Maximum width of the run. Instruments used for measuring shall Measuring instruments such as vernier
be calibrated, verified, or validated, as callipers, micrometer callipers, etc. are
appropriate. covered by several EN-, ISO- and nation-
al standards.
Table 10 — Weaving for mechanized or automatic welding (if applied)
Designation Need for calibration, verification, or  Instruments and techniques
validation
Max. weaving or amplitude Instruments used for measuring shall Measuring instruments such as vernier
be calibrated, verified, or validated, as callipers, micrometer callipers, etc. are
appropriate. covered by several EN-, ISO- and nation-
al standards.
Frequency Calibration, verification, or validation not
required, provided size (penetration) and
—
position of weld can be determined by
non- destructive testing.
Dwell time of oscillation Calibration, verification, or validation not
required, provided size (penetration) and
—
position of weld can be determined by
non- destructive testing.
Torch, electrode and/or wire Instruments used for measuring shall Measuring instruments such as vernier
angle be calibrated, verified or validated, as callipers, micrometer callipers, etc. are
appropriate. covered by several EN-, ISO- and nation-
al standards.
Table 11 — Electrical variables
Designation Need for calibration, verification, or  Instruments and techniques
validation
Weld current (mean) Ammeters shall be calibrated. See IEC 60974-14. Mean value of
(rectified) current.
Arc voltage (mean) Voltmeters shall be calibrated. See IEC 60974-14. Mean value of
(rectified) arc voltage.
Watt meter Instantaneous energy or instantaneous See ISO/TR 18491.
power measurements shall be calibrated.
The signal should be monitored continuously. The sampling time should be sufficient to give a reasonably stable reading. If tong-
tests are used for measurement of current, the difference between mean value and RMS value measuring instruments should be
taken into consideration.
ISO 17662:2025(en)
Table 12 — Mechanized or automatic welding
Designation Need for calibration, verification, or  Instruments and techniques
validation
Travel speed Measurements by means of stopwatches Stopwatches can be validated by com-
and tape measure/steel rulers. Appropri- parison with any reasonably accurate
ate steel rulers need not to be calibrated, clock or watch.
verified or validated provided the rulers
See also IEC 60974-14.
are not visibly damaged.
Wire feed speed Measurements by means of stopwatches Stopwatches can be validated by com-
and rulers. Appropriate steel rulers need parison with any reasonably accurate
not to be calibrated, verified or validated clock or watch.
provided the rulers are not visibly dam-
See also IEC 60974-14.
aged.
6  Metal arc welding without gas protection (group 11)
NOTE The explanation of the reference numbers for the processes are given in ISO 4063.
Provisions for specification of welding procedures are specified in ISO 15609-1. Calibration, verification, or
validation can be needed for the welding data stated in Table 13.
Table 13 — Manual metal arc welding (group 111)
Designation Need for calibration, verification, or  Instruments and techniques
validation
The run-out length of electrode Calibration, verification and validation —
consumed not required, provided appropriate steel
rulers are used and the rulers are not visi-
bly damaged.
7  Plasma arc welding (group 15)
Provisions for specification of welding procedures are given in ISO 15609-1. Calibration, verification, or
validation can be needed for the welding data stated in Table 14.
Table 14 — Plasma arc welding (group 15)
Designation Need for calibration, verification, or  Instruments and techniques
validation
Plasma gas flow rate Validation to an accuracy of ±0,1 l/min. Appropriate standards for the equip-
ment shall be consulted.
Plasma gas nozzle diameter The welding operator usually detects Nozzle changed, if required.
wear of the nozzle by changes in the arc.
Distance between electrode Distance between plasma gas nozzle to These instruments shall be validat-
and plasma gas nozzle and the workpiece surface is usually kept ed, usually by ordinary measuring
plasma gas nozzle to the work- constant by: instruments such as vernier, callipers,
piece surface micrometer callipers, etc.
—  arc sensor measuring with automatic
voltage Control (AVC);
—  control by tactile device;
—  laser scanner.
Distance between electrode and plasma
gas nozzle is usually kept constant by:
—  gauge.
ISO 17662:2025(en)
8  Resistance welding (groups 21, 22, 23, 24, and 25)
Resistance welding is mainly used for mass production and calibration, verification and validation can then
be omitted (see 4.3).
Productio
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