Hollow metallic waveguides - Part 1: General requirements and measuring methods

IEC 60153-1:2016 specifies straight hollow metallic tubing for use as waveguides in electronic equipment. It covers:
a) the details necessary to ensure compatibility and, as far as essential, interchangeability;
b) test methods;
c) uniform requirements for the electrical and mechanical properties.
It should be noted that no recommendations are made for the materials to be used for waveguides. The choice of material is agreed between customer and manufacturer. This edition includes the following significant technical changes with respect to the previous edition:
a) expand the operation frequency range;
b) revise the equation of attenuation.
This publication is to be read in conjunction with IEC 60154 series .

Guides d'ondes métalliques creux - Partie 1: Exigences générales et méthodes de mesure

L'IEC 60153-1:2016 spécifie des tubes métalliques creux droits destinés à être utilisés comme guides d'ondes dans les équipements électroniques. Elle couvre:
a) les détails nécessaires pour assurer la compatibilité et, dès lors que c'est essentiel, l'interchangeabilité;
b) les méthodes d essai;
c) les exigences uniformes pour les propriétés électriques et mécaniques.
Il convient de noter qu'aucune recommandation n'est faite en ce qui concerne les matériaux à utiliser pour les guides d'ondes. Le choix des matériaux fait l'objet d'un accord entre le client et le fabricant. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) extension de la plage de fréquences de fonctionnement;
b) révision des équations d'affaiblissement.
Cette publication doit être lue conjointement avec la série IEC 60154 .

General Information

Status
Published
Publication Date
17-May-2016
Current Stage
PPUB - Publication issued
Completion Date
18-May-2016
Ref Project

Buy Standard

Standard
IEC 60153-1:2016 - Hollow metallic waveguides - Part 1: General requirements and measuring methods
English and French language
28 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

IEC 60153-1
Edition 2.0 2016-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Hollow metallic waveguides –
Part 1: General requirements and measuring methods
Guides d'ondes métalliques creux –
Partie 1: Exigences générales et méthodes de mesure
IEC 60153-1:2016-05(en-fr)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2016 IEC, Geneva, Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form

or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from

either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC

copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or

your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite

ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie

et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des

questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez

les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland www.iec.ch
About the IEC

The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes

International Standards for all electrical, electronic and related technologies.
About IEC publications

The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the

latest edition, a corrigenda or an amendment might have been published.
IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org

The stand-alone application for consulting the entire The world's leading online dictionary of electronic and

bibliographical information on IEC International Standards, electrical terms containing 20 000 terms and definitions in

Technical Specifications, Technical Reports and other English and French, with equivalent terms in 15 additional

documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical

iPad. Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary

The advanced search enables to find IEC publications by a 65 000 electrotechnical terminology entries in English and

variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of

committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been

and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc

details all new publications released. Available online and If you wish to give us your feedback on this publication or

also once a month by email. need further assistance, please contact the Customer Service

Centre: csc@iec.ch.
A propos de l'IEC

La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des

Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC

Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la

plus récente, un corrigendum ou amendement peut avoir été publié.
Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient 20 000 termes et définitions en anglais
Spécifications techniques, Rapports techniques et autres
et en français, ainsi que les termes équivalents dans 15
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.
Recherche de publications IEC - www.iec.ch/searchpub
Glossaire IEC - std.iec.ch/glossary

La recherche avancée permet de trouver des publications IEC 65 000 entrées terminologiques électrotechniques, en anglais

en utilisant différents critères (numéro de référence, texte, et en français, extraites des articles Termes et Définitions des

comité d’études,…). Elle donne aussi des informations sur les publications IEC parues depuis 2002. Plus certaines entrées

projets et les publications remplacées ou retirées. antérieures extraites des publications des CE 37, 77, 86 et

CISPR de l'IEC.
IEC Just Published - webstore.iec.ch/justpublished
Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just

Published détaille les nouvelles publications parues. Si vous désirez nous donner des commentaires sur cette

Disponible en ligne et aussi une fois par mois par email. publication ou si vous avez des questions contactez-nous:

csc@iec.ch.
---------------------- Page: 2 ----------------------
IEC 60153-1
Edition 2.0 2016-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Hollow metallic waveguides –
Part 1: General requirements and measuring methods
Guides d'ondes métalliques creux –
Partie 1: Exigences générales et méthodes de mesure
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.120.10 ISBN 978-2-8322-3382-5

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC 60153-1:2016 © IEC 2016
CONTENTS

FOREWORD ......................................................................................................................... 3

INTRODUCTION ................................................................................................................... 5

1 Scope ............................................................................................................................ 6

2 Normative references..................................................................................................... 6

3 Terms and definitions .................................................................................................... 6

4 Type designation ........................................................................................................... 7

4.1 Type ..................................................................................................................... 7

4.2 Designation ........................................................................................................... 7

5 Standard atmospheric conditions for testing ................................................................... 8

6 Visual inspection ........................................................................................................... 8

7 Mechanical requirements ............................................................................................... 8

7.1 Dimensions ........................................................................................................... 8

7.1.1 General ......................................................................................................... 8

7.1.2 Ordinary rectangular waveguides ................................................................... 9

7.1.3 Rectangularity of cross-section ..................................................................... 10

7.1.4 Flat rectangular waveguides ......................................................................... 10

7.1.5 Circular waveguides ..................................................................................... 11

7.2 Other mechanical requirements ........................................................................... 11

7.2.1 Bow ............................................................................................................. 11

7.2.2 Twist ............................................................................................................ 12

7.2.3 Surface roughness ....................................................................................... 12

7.2.4 Internal stress .............................................................................................. 12

8 Electrical tests ............................................................................................................. 12

8.1 Attenuation ......................................................................................................... 12

8.2 Internal reflections from irregularity of internal dimensions ................................... 13

9 Additional tests – Gas tightness ................................................................................... 14

---------------------- Page: 4 ----------------------
IEC 60153-1:2016 © IEC 2016 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOLLOW METALLIC WAVEGUIDES –
Part 1: General requirements and measuring methods
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,

Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC

Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested

in the subject dealt with may participate in this preparatory work. International, governmental and non-

governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely

with the International Organization for Standardization (ISO) in accordance with conditions determined by

agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence

between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in

the latter.

5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity

assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any

services carried out by independent certification bodies.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC

Publications.

8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 60153-1 has been prepared by subcommittee 46F: RF and

microwave passive components, of IEC technical committee 46: Cables, wires, waveguides,

RF connectors, RF and microwave passive components and accessories.

This second edition cancels and replaces the first edition published in 1964. This edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:
a) expand the operation frequency range;
b) revise the equation of attenuation.
---------------------- Page: 5 ----------------------
– 4 – IEC 60153-1:2016 © IEC 2016
The text of this standard is based on the following documents:
CDV Report on voting
46F/302/CDV 46F/316/RVC

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

It is to be read in conjunction with IEC 60154: Flanges for waveguides.

A list of all parts in the IEC 60153 series, published under the general title Hollow metallic

waveguides, can be found on the IEC website.

The committee has decided that the contents of this publication will remain unchanged until

the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data

related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
---------------------- Page: 6 ----------------------
IEC 60153-1:2016 © IEC 2016 – 5 –
INTRODUCTION

This International Standard relates to straight hollow metallic tubing for use as waveguides in

electronic equipment. In recent years, the operation frequency of waveguide components and

systems has been extended to 1 THz and above. However, the first edition of the IEC 60153

series of standards only specified the aperture dimensions for ordinary rectangular waveguide

for frequencies up to 325 GHz. In addition, the first edition of the IEC 60153 series of

standards, dating from the 1960's, does not meet the needs of the current applications. This

new edition of IEC 60153-1 addresses these two issues by extending the frequency coverage

to 3 300 GHz and by addressing current applications for this type of waveguide.
This standard takes into account IEC 60068 when necessary.

When there is a difference between the general requirements and the relevant specification

sheet, the latter prevails.
---------------------- Page: 7 ----------------------
– 6 – IEC 60153-1:2016 © IEC 2016
HOLLOW METALLIC WAVEGUIDES –
Part 1: General requirements and measuring methods
1 Scope

This part of IEC 60153 specifies straight hollow metallic tubing for use as waveguides in

electronic equipment.
It covers:

a) the details necessary to ensure compatibility and, as far as essential, interchangeability;

b) test methods;
c) uniform requirements for the electrical and mechanical properties.

It should be noted that no recommendations are made for the materials to be used for

waveguides. The choice of material is agreed between customer and manufacturer.
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.
IEC 60050 (all parts), International Electrotechnical Vocabulary (available at
IEC 60068 (all parts), Environmental testing
IEC 60154, Flanges for waveguides
IEC 60261, Sealing test for pressurized waveguide tubing and assemblies
3 Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 60050, as well as

the following apply.
3.1
type test

complete series of tests to be carried out on a number of specimens representative of the

type, with the object of determining whether a particular manufacturer can be considered to

be able to produce products meeting the specification
3.2
type approval

decision by the proper authority (the customer himself or his nominee) that a particular

manufacturer can be considered to be able to produce in reasonable quantities the type

meeting the specification
---------------------- Page: 8 ----------------------
IEC 60153-1:2016 © IEC 2016 – 7 –
3.3
acceptance tests

tests carried out to determine the acceptability of a consignment on the basis of an agreement

between customer and manufacturer
Note 1 to entry: The agreement shall cover:
a) the sample size,
b) the selection of tests,

c) the extent to which the specimens shall conform to the requirements for the selected tests of the specification.

Note 2 to entry: In cases of divergent test results, the IEC standard test methods shall be used for acceptance

tests.

As these recommendations only cover type tests, these definitions are included only for brief information of testing

specification.
3.4
factory tests

tests carried out by the manufacturer to verify that their products meet the specification

4 Type designation
4.1 Type

Type of products comprises similar design features manufactured by the same techniques and

falling within the manufacturer's usual range of ratings for these products.

NOTE 1 Mounting accessories are ignored, provided they have no significant effect on the test results.

NOTE 2 Ratings cover the combination of:
a) electrical ratings,
b) sizes,
c) environmental group.

NOTE 3 The limits of the range of ratings shall be agreed between customer and manufacturer.

4.2 Designation

The reference indication for waveguides covered by this specification shall comprise the

following:
a) the number of the IEC publication (60153);
b) the letters “IEC";
c) a hyphen;
d) a letter indicating the shape of the inside cross-section of the waveguide:
R = ordinary rectangular (with a ratio of height to width of approximately 1:2)
F = flat rectangular
C = circular.

For other types of waveguides this letter indication shall be in accordance with the

relevant specification sheets;

e) a number characterizing a particular size of waveguide. This number indicates a

frequency characteristic of the waveguide;

f) where necessary, an additional indication as indicated on the relevant specification sheets.

The letter “P" shall be used to indicate close tolerance types.
Example:
---------------------- Page: 9 ----------------------
– 8 – IEC 60153-1:2016 © IEC 2016

"60153 IEC-R 100" denotes a 22,860 mm × 10,160 mm (0,900 in × 0,400 in) ordinary rectangular waveguide with a

centre frequency of approximately 10 GHz in the dominant mode.
5 Standard atmospheric conditions for testing

Unless otherwise specified, all tests shall be carried out under standard atmospheric

conditions for testing as specified in IEC 60068.
Before the measurements are made, the waveguide shall be stored at the measuring

temperature for a time sufficient to allow the entire waveguide to reach this temperature.

When measurements are made at a temperature other than the specified temperature, the

results shall, where necessary, be corrected to the specified temperature. The ambient

temperature at which the measurements are made shall be stated in the test report.

As these recommendations only cover type tests, these definitions are included only for brief

information of testing conditions.
6 Visual inspection

The waveguides shall be uniform in composition and in wall thickness and shall be straight

and smooth from end to end. There shall be no burrs, cracks, die marks, chatter marks, dirt,

grease or other irregularities of the surface.

Both inner and outer surface shall have a clean bright appearance in accordance with good

current practice.
7 Mechanical requirements
7.1 Dimensions
7.1.1 General

The dimensions of the waveguides and the tolerances thereon shall be in accordance with the

values given on the relevant specification sheets. Dimensions and tolerance shall be given

both in millimetres and inches, indicating in which system of units the dimensions were

originated.

Independent of the system of units, the nominal dimensions of the inside and outside cross

section shall be given in such a way that the values, the first digit of which is 3 to 9, should be

given by 4 significant figures and those with first digits being 1 or 2 by 5 significant figures. In

principle, internal nominal dimensions shall be rounded off to the nearest 0,001 mm or

0,0001 in and external dimensions should be rounded off to the nearest 0,01 mm or 0,001 in.

NOTE When these rules are applied, a junction of two hypothetical waveguides each with a nominal value in one

of the systems will produce a calculated reflection of less than –70 dB for ordinary rectangular waveguides, except

for the smaller types.
---------------------- Page: 10 ----------------------
IEC 60153-1:2016 © IEC 2016 – 9 –

Unless otherwise specified, the following dimensions shall be given on the relevant

specification sheets:
a) nominal dimensions of inside cross-section,
b) tolerances on inside dimensions,
c) maximum radius of inside corner for rectangular waveguides,
d) nominal wall thickness,
e) maximum eccentricity,
f) nominal dimensions of outside cross-section,
g) tolerance on outside dimensions,
h) minimum and maximum radius of outside corner for rectangular waveguides,
i) ellipticity for circular waveguides.
7.1.2 Ordinary rectangular waveguides
7.1.2.1 Inside dimensions

The standard ratio between height and width of the inside cross-section is 1:2. (For some

sizes the ratio between height and width differs somewhat from this ratio. These sizes were

chosen because they were already extensively used). If closer tolerances are necessary, a

ratio of ± 1/1 000 is recommended.

The tolerances both on width and height are given on the relevant specification sheet. Inside

corner radii shall be as given on the relevant specification sheet.
7.1.2.2 Wall thickness

The nominal wall thickness is defined as half the difference between nominal outside and

inside dimensions in the original system of units. Its value shall be given on the relevant

specification sheets for information.

After conversion from inches into millimetres, the values shall be rounded to the nearest

0,005 mm.

After conversion from millimetres into inches, the values shall be rounded to the nearest

0,001 in.
7.1.2.3 Outside dimensions

Nominal values of height and width shall be as given on the relevant specification sheet.

No outside dimensions have been specified for some of the largest sizes because a variety of

manufacturing techniques are used.
The outside corner radius (r ) shall be within the following limits:
r min = 0,5 d
r max = r min + 0,5 mm (0,02 in)
2 2
where d is the nominal wall thickness.
---------------------- Page: 11 ----------------------
– 10 – IEC 60153-1:2016 © IEC 2016
7.1.3 Rectangularity of cross-section
7.1.3.1 General

The dimensional requirements in the IEC 60153 series do not control the rectangularity of the

cross-section.

The allowed deviation from rectangularity is defined by the requirement that the shape of the

inside (outside) cross-section shall be such that it is possible to inscribe the actual internal

(external) cross-section in the area between the specified maximum and minimum internal

(external) rectangles. A suitable method for checking rectangularity is given below by way of

example.

Calliper or three dimensional coordinate measuring machine (3DCMM) or similar dimensional

measurement equipment should be used in the cross-sectional dimensions.
7.1.3.2 For inside cross-section

In drawing the block through the waveguide, precaution shall be taken to keep it accurately

normal to the waveguide axis.
For the dimensions of the block, the following applies:

a) nominal dimensions of cross-section: nominal waveguide aperture size minus 1,1 times

the tolerance,

b) tolerance on nominal dimensions of cross-section: +0, –0,1 times tolerance on waveguide

aperture,
c) perpendicularity of the sides: not deviating by more than 3 × 10 radian,
d) length 0,2 times internal width of the waveguide.
7.1.3.3 For outside cross-section
For the dimensions of the aperture, the following applies:

a) nominal dimensions of cross-section: nominal waveguide outside cross-section plus

1,1 times the tolerance,

b) tolerance on nominal dimensions of cross-section: –0, +0,1 times tolerance on waveguide

outside cross-section,
c) perpendicularity of the sides: not deviating by more than 3 × 10 radian.
7.1.4 Flat rectangular waveguides
7.1.4.1 Inside dimensions

The inside width of flat rectangular waveguides shall, except for special types, be equal to the

inside width of corresponding sizes of ordinary rectangular waveguides.

The standard ratio between height and width of the inside cross-section is 1:8,33, but for the

smaller sizes a fixed height is recommended.

The tolerances both on height and width shall be as given on the relevant specification sheet.

Further 1:4 is recommended as an intermediate between the standard ratios of 1:2 and 1:8,33.

When it is necessary to deviate from a standard dimension, it is recommended that the value

be based on the geometrical mean between two consecutive standardized dimensions.

---------------------- Page: 12 ----------------------
IEC 60153-1:2016 © IEC 2016 – 11 –
7.1.4.2 Wall thickness
The same rules shall be followed as for ordinary rectangular waveguides.
7.1.4.3 Eccentricity
The same rules shall be followed as for ordinary rectangular waveguides.
7.1.4.4 Outside dimensions

The tolerances both on width and height shall be as given on the relevant specification sheet.

If necessary, outside dimension should be specified for waveguides operating at frequencies

over 330 GHz.
7.1.4.5 Rectangularity of cross-section
The same rules shall be followed as for ordinary rectangular waveguides.
7.1.5 Circular waveguides
7.1.5.1 Inside dimensions
a) Diameter

The tolerances on diameter shall be as given on the relevant specification sheet.

b) Ellipticity
The ellipticity “E" is defined as E = (D – D )/D
max min nom
where
D is the nominal inside diameter;
nom
D is the largest measured inside dimension;
max
D is the smallest measured inside dimension.
min

The ellipticity shall not exceed the requirements given on the relevant specification sheet.

7.1.5.2 Wall thickness

For wall thickness, the same rules shall be applied as for ordinary rectangular waveguides.

7.1.5.3 Eccentricity

For eccentricity, the same rules shall be applied as for ordinary rectangular waveguides.

7.1.5.4 Outside dimensions

The nominal values for outside dimensions and the tolerances thereon shall be as given on

the relevant specification sheet.

No outside dimensions have been specified for some of the largest sizes because a variety of

manufacturing techniques are used.
7.2 Other mechanical requirements
7.2.1 Bow

Bow is defined as the maximum deviation of the actual axis of the waveguide from a straight

line of specified length connecting two points on that axis.
---------------------- Page: 13 ----------------------
– 12 – IEC 60153-1:2016 © IEC 2016

The bow is measured on the external surface of the waveguide. For a length of 10 times the

internal width, the external bow shall not exceed 10 times the specified tolerance on the

internal width.

For a length of 50 times the internal width, the external bow shall not exceed 40 times the

specified tolerance on the internal width.

For the determination of the external bow, the waveguide shall be so positioned that gravity

does not tend to affect the amount of bow.
7.2.2 Twist

Twist is defined as the rotation, over a specified length, of the cross-section of the waveguide

around the longitudinal axis.
The rate of twist shall not exceed:

• 0,50 per metre for waveguides with an internal width equal or larger than 100 mm;

• 0,50 per length of waveguide equal to ten times the internal width when the latter is less

than 100 mm.

Over a length equal to 50 times the internal width of the waveguide, the accumulated twist

shall not exceed 2°. The direction of twist should not be systematic in a batch of waveguides.

7.2.3 Surface roughness
Under consideration.
7.2.4 Internal stress
The waveguid
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.