ISO 29821-2:2016

Condition monitoring and diagnostics of machines — Ultrasound — Part 2: Procedures and validation

ISO 29821-2:2016 - provides guidance on establishing severity assessment criteria for anomalies identified by airborne (AB) and structure borne (SB) ultrasound, - outlines methods and requirements for carrying out ultrasonic examination of machines, including safety recommendations and sources of error, and - provides information relative to data interpretation, assessment criteria and reporting.

Surveillance des conditions et diagnostic d'état des machines — Ultrasons — Partie 2: Modes opératoires et validation

General Information

• Status: Withdrawn
• Publication Date: 03-Apr-2016
• Withdrawal Date: 03-Apr-2016
• ICS: 17.160 - Vibrations, shock and vibration measurements
• Technical Committee: ISO/TC 108/SC 5 - Condition monitoring and diagnostics of machine systems
• Drafting Committee: ISO/TC 108/SC 5 - Condition monitoring and diagnostics of machine systems
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 25-Jan-2018

Relations

• Revised: ISO 29821:2018 - Condition monitoring and diagnostics of machines — Ultrasound — General guidelines, procedures and validation
• Effective Date: 23-Apr-2016

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 29821-2
First edition
2016-04-15
Condition monitoring and diagnostics
of machines — Ultrasound —
Part 2:
Procedures and validation
Surveillance des conditions et diagnostic d’état des machines —
Ultrasons —
Partie 2: Modes opératoires et validation
Reference number
ISO 29821-2:2016(E)
©
ISO 2016

---------------------- Page: 1 ----------------------
ISO 29821-2:2016(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2016 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 29821-2:2016(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Ultrasonic condition monitoring . 1
4.1 Application of airborne and structure-borne ultrasound within condition
monitoring programmes . 1
4.2 Correlation with other technologies . 2
5 Equipment choice . 2
5.1 Kinds of sensors . 2
5.2 Airborne sensor choice . 2
5.3 Structure-borne sensor choice . 2
5.4 Instrument characteristics . 3
5.4.1 General. 3
5.4.2 Frequency response . 3
6 Data collection guidelines . 3
6.1 General . 3
6.2 Error sources, accuracy, and repeatability . 5
7 Assessment criteria . 5
8 Interpretation guidelines . 5
9 Diagnosing ultrasonic problems . 6
9.1 Principles of diagnostics using ultrasound . 6
9.2 Generation of ultrasound . 6
9.2.1 Surface friction . 6
9.2.2 Fluid flow . 6
9.2.3 Ionization . 6
10 Reporting . 6
Annex A (informative) Example of a generic sensitivity validation procedure: Ultrasonic
tone generator method . 7
Bibliography . 9
© ISO 2016 – All rights reserved iii

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ISO 29821-2:2016(E)

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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 108, Mechanical vibration, shock and condition
monitoring, Subcommittee SC 5, Condition monitoring and diagnostics of machine systems.
ISO 29821 consists of the following parts, under the general title Condition monitoring and diagnostics of
machines — Ultrasound:
— Part 1: General guidelines
— Part 2: Procedures and validation
iv © ISO 2016 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 29821-2:2016(E)

Introduction
This part of ISO 29821 provides specific guidance on the interpretation of ultrasonic readings and
wave files or frequency and time domain printouts (sometimes called “sound images”) as part of a
programme for condition monitoring and diagnostics of machines. Airborne (AB) and structure-borne
(SB) ultrasound can be used to detect abnormal performance or machine anomalies. The anomalies
are detected as high frequency acoustic events caused by turbulent flow, ionization events and friction,
which are caused, in turn, by incorrect machinery operation, leaks, improper lubrication, worn
components, and/or electrical discharges.
Airborne and structure-borne ultrasound is based on measuring the high frequency sound that is
generated by either turbulent flow, friction or by the ionization created from the anomalies. The
inspector therefore requires an understanding of ultrasound and how it propagates through the
atmosphere and through structures as a prerequisite to the creation of an airborne and structure-
borne ultrasound programme. Ultrasonic energy is present with the operation of all machines. It can
be in the form of friction, turbulent flow and/or ionization as a property of the process, or produced
by the process itself. As a result, ultrasonic emissions are created and these are an ideal parameter
for monitoring the performance of machines, the condition of machines, and for diagnosing machine
anomalies. Ultrasound is an ideal technology to do this monitoring because it provides an efficient way
to quickly and non-invasively determine the location of an anomaly with little setup and in a very short
period of time.
© ISO 2016 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 29821-2:2016(E)
Condition monitoring and diagnostics of machines —
Ultrasound —
Part 2:
Procedures and validation
1 Scope
This part of ISO 29821
— provides guidance on establishing severity assessment criteria for anomalies identified by airborne
(AB) and structure borne (SB) ultrasound,
— outlines methods and requirements for carrying out ultrasonic examination of machines, including
safety recommendations and sources of error, and
— provides information relative to data interpretation, assessment criteria and reporting.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 13372, Condition monitoring and diagnostics of machines — Vocabulary
ISO 29821-1:2011, Condition monitoring and diagnostics of machines — Ultrasound — Part 1: General
guidelines
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13372 and ISO 29821-1 apply.
4 Ultrasonic condition monitoring
4.1 Application of airborne and structure-borne ultrasound within condition
monitoring programmes
Ultrasound is not normally used as a primary monitoring technique in typical condition monitoring
programmes. The exceptions to this are when ultrasound is preferred as a non-invasive indicator of
impending failure or performance deterioration or when rapid pressure or vacuum leak localization is
necessary to lessen machine performance degradation.
Examples of such applications are:
— electrical transformers;
— enclosed electrical systems;
— gearboxes;
— motors;
© ISO 2016 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO 29821-2:2016(E)

— pumps;
— conveyor bearings;
— lubrication failure;
— compressors;
— turbine engines;
— condensers;
— heat exchangers;
— compressed gas systems.
4.2 Correlation with other technologies
Traditionally, airborne and structure-borne ultrasonic inspection is used in a condition-monitoring
programme to detect characteristics of failure modes that have been previously identified by another
technology. There are instances where airborne or structure-borne ultrasound is the first indicator of
a failure mode, such as in the detection of faulty slow-speed bearings and/or insufficient lubrication
in rolling element bearings. Airborne or structure-borne ultrasound can also be used to identify a
potential safety hazard to an inspector using an alternate technology, for example in the inspection of
enclosed electrical systems. Airborne and structure-borne ultrasound are used to determine if an arc
flash hazard is present before opening the cabinet for an infrared thermographic inspection.
5 Equipment choice
5.1 Kinds of sensors
Airborne ultrasound is propagated through an atmosphere (air or gas) and detected with an ultrasonic
microphone while structure-borne ultrasound is generated within and propagated through a structure
and is usually detected with a contact module, although other sensors may be used. A guide for which
sensor should be chosen can be found in ISO 29821-1:2011, Table 1.
5.2 Airborne sensor choice
An ultrasonic instrument with fixed sensors might have limitations with respect to field of reception
and might not be suitable for all applications. For ultrasonic instruments with interchangeable sensors,
there is normally a choice of two kinds of sensors: wide-angle and parabolic.
For machine condition monitoring
...

DRAFT INTERNATIONAL STANDARD
ISO/DIS 29821-2
ISO/TC 108/SC 5 Secretariat: ANSI
Voting begins on: Voting terminates on:
2015-09-15 2015-12-15
Condition monitoring and diagnostics of machines —
Ultrasound —
Part 2:
Procedures and validation
Surveillance des conditions et diagnostic d’état des machines — Ultrasons —
Partie 2: Modes opératoires et validation
ICS: 17.160
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 29821-2:2015(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2015

---------------------- Page: 1 ----------------------
ISO/DIS 29821-2:2015(E) ISO/DIS 29821-2

Contents Page
Foreword .iii
Introduction . iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Ultrasonic condition monitoring . 1
4.1 Application of airborne and structure-borne ultrasound within condition
monitoring programmes . 1
4.2 Correlation with other technologies . 2
5 Equipment choice . 2
5.1 Kinds of sensors . 2
5.2 Airborne sensor choice . 2
5.3 Structure-borne sensor choice . 3
5.4 Instrument characteristics . 3
6 Data collection guidelines . 4
6.1 General . 4
6.2 Error sources, accuracy, and repeatability . 4
7 Assessment criteria . 5
8 Interpretation guidelines . 5
9 Diagnosing ultrasonic problems . 6
9.1 Principles of diagnostics using ultrasound . 6
9.2 Generation of ultrasound . 6
10 Reporting . 6
Annex A (informative) Example of a generic sensitivity validation procedure: Ultrasonic
tone generator method . 7
Bibliography . 9


COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved
2 © ISO 2015 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/DIS 29821-2
Contents Page
Foreword .iii
Introduction . iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Ultrasonic condition monitoring . 1
4.1 Application of airborne and structure-borne ultrasound within condition
monitoring programmes . 1
4.2 Correlation with other technologies . 2
5 Equipment choice . 2
5.1 Kinds of sensors . 2
5.2 Airborne sensor choice . 2
5.3 Structure-borne sensor choice . 3
5.4 Instrument characteristics . 3
6 Data collection guidelines . 4
6.1 General . 4
6.2 Error sources, accuracy, and repeatability . 4
7 Assessment criteria . 5
8 Interpretation guidelines . 5
9 Diagnosing ultrasonic problems . 6
9.1 Principles of diagnostics using ultrasound . 6
9.2 Generation of ultrasound . 6
10 Reporting . 6
Annex A (informative) Example of a generic sensitivity validation procedure: Ultrasonic
tone generator method . 7
Bibliography . 9


2 © ISO 2015 – All rights reserved

---------------------- Page: 3 ----------------------
ISO/DIS 29821-2
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 documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received. www.iso.org/patents
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO's adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 108, Mechanical vibration, shock and condition
monitoring, Subcommittee SC 5, Condition monitoring and diagnostics of machine systems.
ISO 29821 consists of the following parts, under the general title Condition monitoring and diagnostics of
machines — Ultrasound:
 Part 1: General guidelines
---- Part 2: Procedures and validation
© ISO 2015 – All rights reserved 3

---------------------- Page: 4 ----------------------
ISO/DIS 29821-2
Introduction
This part of ISO 29821 provides specific guidance on the interpretation of ultrasonic readings and wave
files or frequency and time domain printouts (sometimes called "sound images") as part of a
programme for condition monitoring and diagnostics of machines. Airborne (AB) and structure-borne
(SB) ultrasound can be used to detect abnormal performance or machine anomalies. The anomalies are
detected as high frequency acoustic events caused by turbulent flow, ionization events and friction,
which are caused, in turn, by incorrect machinery operation, leaks, improper lubrication, worn
components, and/or electrical discharges.
Airborne and structure-borne ultrasound is based on measuring the high frequency sound that is
generated by either turbulent flow, friction or by the ionization created from the anomalies. The
inspector therefore requires an understanding of ultrasound and how it propagates through the
atmosphere and through structures as a prerequisite to the creation of an airborne and structure-borne
ultrasound programme. Ultrasonic energy is present with the operation of all machines. It can be in the
form of friction, turbulent flow and/or ionization as a property of the process, or produced by the
process itself. As a result, ultrasonic emissions are created and these are an ideal parameter for
monitoring the performance of machines, the condition of machines, and for diagnosing machine
anomalies. Ultrasound is an ideal technology to do this monitoring because it provides an efficient way
to quickly and non-invasively determine the location of an anomaly with little setup and in a very short
period of time.





4 © ISO 2015 – All rights reserved

---------------------- Page: 5 ----------------------
DRAFT INTERNATIONAL STANDARD ISO/DIS 29821-2

Condition monitoring and diagnostics of machines —
Ultrasound — Part 2: Procedures and validation
1 Scope
This part of ISO 29821
 provides guidance on establishing severity assessment criteria for anomalies identified by airborne
(AB) and structure borne (SB) ultrasound.
 outlines methods and requirements for carrying out ultrasonic examination of machines, including
safety recommendations and sources of error.
 provides information relative to data interpretation, assessment criteria and reporting.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 13372, Condition monitoring and diagnostics of machines — Vocabulary
ISO 29821-1:2011 Condition monitoring and diagnostics of machines --- Ultrasound ---Part 1: General
Guidelines
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13372 and ISO 29821-1 apply.
4 Ultrasonic condition monitoring
4.1 Application of airborne and structure-borne ultrasound within condition monitoring
programmes
Ultrasound is not normally used as a primary monitoring technique in typical condition monitoring
programmes. The exceptions to this are when ultrasound is preferred as a non-invasive indicator of
impending failure or performance deterioration or when rapid pressure or vacuum leak localization is
necessary to lessen machine performance degradation.
Examples of such applications are:
 electrical transformers;
 enclosed electrical systems;
 gearboxes;
 motors;
© ISO 2015 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO/DIS 29821-2
 pumps;
 conveyor bearings;
 lubrication failure;
 compressors;
 turbine engines;
 condensers;
 heat exchangers;
 compressed gas systems.
4.2 Correlation with other technologies
Traditionally, airborne and structure-borne ultrasound inspection is used in a condition-monitori
...