ISO 17089-2:2012

INTERNATIONAL ISO
STANDARD 17089-2
First edition
2012-10-01
Measurement of fluid flow in closed
conduits — Ultrasonic meters for gas —
Part 2:
Meters for industrial applications
Mesurage de débit des fluides dans les conduites fermées —
Compteurs à ultrasons pour gaz —
Partie 2: Compteurs pour applications industrielles
Reference number
©
ISO 2012
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 ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved

Contents Page
Foreword .iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, and symbols . 1
3.1 Terms and definitions . 1
3.2 Symbols and subscripts . 6
3.3 Abbreviations . 7
4 Principles of measurement . 7
4.1 Transit time ultrasonic meters . 7
4.2 Flare or vent gas meters . 8
4.3 Factors affecting performance . 9
4.4 Description of generic types . 9
4.5 Impact of pressure and temperature on the flowmeter geometry .14
4.6 USM measurement uncertainty determination .14
4.7 USM classification .14
5 Meter characteristics .15
5.1 Performance indications .15
5.2 Operating conditions .15
5.3 Meter body, materials, and construction .15
5.4 Connections .16
5.5 Dimensions .16
5.6 Ultrasonic ports .16
5.7 Pressure tapping .16
5.8 Anti-roll provision .16
5.9 Flow conditioner .17
5.10 Markings .17
5.11 Transducers .17
5.12 Electronics .17
5.13 Firmware and software .18
5.14 Inspection and verification functions .19
5.15 Operation and installation requirements .19
5.16 Installation requirements and flow profile considerations .21
5.17 Handling and transportation .22
6 Test and calibration .23
6.1 Flow test and calibration .23
6.2 Static testing for leakage and pressure .23
6.3 Dimensional measurements .23
6.4 Dynamic testing (testing and calibration, adjustment under flowing conditions) .25
6.5 Meter diagnostics .26
6.6 In situ verification .27
Annex A (normative) Special application note on valve characterization and noise .29
Bibliography .36
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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 17089-2 was prepared by Technical Committee ISO/TC 30, Measurement of fluid flow in closed conduits,
Subcommittee SC 5, Velocity and mass methods.
ISO 17089 consists of the following parts, under the general title Measurement of fluid flow in closed conduits —
Ultrasonic meters for gas:
— Part 1: Meters for custody transfer and allocation measurement
— Part 2: Meters for industrial applications
iv © ISO 2012 – All rights reserved

Introduction
Ultrasonic meters (USMs) for gas flow measurement have penetrated the market for meters rapidly since 2000
and have become one of the prime flowmeter concepts for operational use as well as custody transfer and
allocation measurement. As well as offering high repeatability and high accuracy, ultrasonic technology has
inherent features like: negligible pressure loss, high rangeability and the capability to handle pulsating flows.
USMs can deliver extended diagnostic information through which it may be possible to verify not only the
functionality of a USM, but also several other components within the system, such as the gas chromatograph,
and the pressure and temperature transmitters. Due to the extended diagnostic capabilities, this part of
ISO 17089 advocates the addition and use of automated diagnostics instead of labour-intensive quality checks.
This part of ISO 17089 focuses on meters for industrial gas applications (class 3 and class 4). Meters for
custody transfer and allocation measurement are the subject of ISO 17089-1.
Typical performance factors of the classification scheme are:
Typical uncertainty 95 %
Class Typical applications confidence level (volume flow Reference
a
rate)
1 Custody transfer ±0,7 % ISO 17089-1
2 Allocation ±1,5 % ISO 17089-1
b
3 Utilities and process ±1,5 % to 5 % for q > q This part of ISO 17089
V V, t
4 Flare gas and vent gas ±5 % to 10 % for q > q This part of ISO 17089
V V, t
a
Meter performance, inclusive of total meter uncertainty, repeatability, resolution and maximum peak-to-peak error, depends upon a
number of factors which include pipe inside diameter, acoustic path length, number of acoustic paths, gas composition and speed of
sound, as well as meter timing repeatability.
b
By specific flow conditioning or when multi-path meters are employed, lower uncertainties may be achieved.
The special application note(s) as presented in Clause 7 as well as information in parentheses are informative.
INTERNATIONAL STANDARD ISO 17089-2:2012(E)
Measurement of fluid flow in closed conduits — Ultrasonic
meters for gas —
Part 2:
Meters for industrial applications
IMPORTANT — The electronic file of this document contains colours which are considered to be
useful for the correct understanding of the document. Users should therefore consider printing this
document using a colour printer.
1 Scope
This part of ISO 17089 specifies requirements and recommendations for ultrasonic gas meters (USMs), which
utilize acoustic signals to measure the flow in the gaseous phase in closed conduits.
This part of ISO 17089 is applicable to transit time USMs and is focused towards industrial flow measurement.
Included are meters comprising meter bodies as well as meters with field-mounted transducers.
There are no limits on the size of the meter. It can be applied to the measurement of almost any type of gas;
such as but not limited to air, hydrocarbon gases, and steam.
This part of ISO 17089 specifies performance, calibration (when required), and output characteristics of USMs
for gas flow measurement and deals with installation conditions.
NOTE It is possible that national or other regulations apply which can be more stringent than those in this part of ISO 17089.
2 Normative references
The following referenced documents are indispensable for the application 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.
lSO 4006, Measurement of fluid flow in closed conduits — Vocabulary and symbols
3 Terms, definitions, and symbols
3.1 Terms and definitions
3.1.1 General
For the purposes of this document, the terms and definitions given in lSO 4006 and the following apply.
3.1.2 Quantities
3.1.2.1
volume flow rate
q
V
dV
q =
V
dt
where
V is volume;
t is time.
[8]
NOTE Adapted from ISO 80000-4:2006, 4-30.
3.1.2.1.1
actual flow rate
volume of fluid per time at metering conditions
3.1.2.1.2
corrected flow rate
volume of fluid per time measured at metering conditions, but converted to equivalent volume at base conditions
3.1.2.2
indication
flow rate indicated by the meter
3.1.2.3
working range
set of values of quantities of the same kind that can be measured by a given measuring instrument or measuring
system with specified instrumental uncertainty, under defined conditions
[10]
NOTE 1 Adapted from ISO/IEC Guide 99:2007, 4.7, “working interval”.
NOTE 2 For the purposes of this part of ISO 17089, the “set of values of quantities of the same kind” are volume flow
rates whose values are bounded by a maximum flow rate, q , and a minimum flow rate, q ; the “given measuring
V, max V, min
instrument” is a meter.
NOTE 3 The terms “rangeability” and “turndown” can often be found in flowmeter data sheets in connection with the
working range of the meter. These ter
...