SIST EN ISO 16911-1:2014

Stationary source emissions - Manual and automatic determination of velocity and volume flow rate in ducts - Part 1: Manual reference method (ISO 16911-1:2013)

EN ISO 16911-1 specifies a method for periodic determination of the axial velocity and volume flow rate of gas within emissions ducts and stacks. It is applicable for use in circular or rectangular ducts with measurement locations meeting the requirements of EN 15259. Minimum and maximum duct sizes are driven by practical considerations of the measurement devices described within EN ISO 16911-1. EN ISO 16911-1 requires all flow measurements to have demonstrable metrological traceability to national or international primary standards. To be used as a standard reference method, the user is required to demonstrate that the performance characteristics of the method are equal to or better than the performance criteria defined in EN ISO 16911-1 and that the overall uncertainty of the method, expressed with a level of confidence of 95 %, is determined and reported. The results for each method defined in EN ISO 16911-1 have different uncertainties within a range of 1 % to 10 % at flow velocities of 20 m/s. Methods further to these can be used provided that the user can demonstrate equivalence, based on the principles of CEN/TS 14793.

Emissionen aus stationären Quellen - Manuelle und automatische Bestimmung der Geschwindigkeit und des Volumenstroms in Abgaskanälen - Teil 1: Manuelles Referenzverfahren (ISO 16911-1:2013)

Diese Norm, die ein Verfahren zur periodischen Bestimmung der Axialgeschwindigkeit und des Volumen-stroms von Gasen in Abgaskanälen und –schächten beschreibt, gilt für die Anwendung in runden oder recht-eckigen Abgaskanälen mit Messstellen, die den Anforderungen von EN 15259 entsprechen. Die minimalen und maximalen Kanalmaße sind durch praktische Erwägungen in Bezug auf die in dieser Norm beschriebenen Messgeräte bedingt.
Diese Norm fordert, dass für sämtliche Durchflussmessungen eine metrologische Rückführbarkeit auf nationale oder internationale Primärnormale nachgewiesen werden kann.
Um als ein Standard-Referenzverfahren angewendet zu werden, muss der Anwender nachweisen, dass die Kenngrößen des Verfahrens im Vergleich zu den in dieser Internationalen Norm definierten Kenngrößen gleichwertig oder besser sind, und dass die Gesamtunsicherheit des Verfahrens, angegeben mit einem Vertrauensniveau von 95 %, bestimmt und berichtet wird. Dieses Verfahren kann typischerweise Messungen mit einer Messunsicherheit von 5 % bei Strömungsgeschwindigkeiten von 20 m  s–1 erzielen.
Anstelle dieses Verfahrens dürfen alternative Verfahren angewendet werden, vorausgesetzt der Anwender kann auf Grundlage der Grundsätze der Technischen Spezifikation CEN/TS 14793 [1] die Gleichwertigkeit dieser Verfahren nachweisen.

Émissions de sources fixes - Détermination manuelle et automatique de la vitesse et du débit-volume d'écoulement dans les conduits - Partie 1: Méthode de référence manuelle (ISO 16911-1:2013)

L'ISO 16911‑1:2013 spécifie une méthode pour la détermination périodique de la vitesse axiale et du débit-volume du gaz dans les conduits et les cheminées à l'émission de sources fixes. Elle est applicable aux conduits rectangulaires ou circulaires ayant des sections de mesurage répondant aux exigences de l'EN 15259. Les tailles de conduit minimales et maximales sont liées à des considérations pratiques sur les dispositifs de mesurage décrits dans l'ISO 16911‑1:2013.
L'ISO 16911‑1:2013 exige que tous les mesurages de débit aient une traçabilité métrologique démontrable par rapport aux Normes internationales ou aux normes nationales de base.
Pour pouvoir l'utiliser comme méthode de référence normalisée, l'utilisateur est tenu de démontrer que les caractéristiques de performance de la méthode sont égales ou supérieures aux critères de performance définis dans l'ISO 16911‑1:2013 et que l'incertitude globale de la méthode, exprimée à un niveau de confiance de 95 %, est déterminée et déclarée. Pour chaque méthode définie dans l'ISO 16911‑1:2013, les résultats ont des incertitudes différentes comprises dans une plage de 1 à 10 % à des vitesses de 20 m/s.
D'autres méthodes que celles-ci peuvent être utilisées à condition que l'utilisateur puisse démontrer leur équivalence, sur la base des principes de la CEN/TS 14793.

Emisije nepremičnih virov - Ročno in avtomatsko določevanje hitrosti in volumenskega pretoka v odvodnikih - 1. del: Ročna referenčna metoda (ISO 16911-1:2013)

EN ISO 16911-1 določa metodo za redno ugotavljanje aksialne hitrosti in volumenskega pretoka plina v odvodnikih emisij. Uporablja se za krožne in pravokotne odvodnike z meritvenimi mesti, ki so skladni z zahtevami standarda EN 15259. Najmanjše in največje velikosti odvodnikov so določene glede na praktične pomisleke za naprave za merjenje, opisane v standardu EN ISO 16911-1. Po EN ISO 16911-1 morajo biti vse meritve pretoka dokazljivo meroslovno sledljive do nacionalnih ali mednarodnih primarnih standardov. Če se uporablja kot standardna referenčna metoda, mora uporabnik dokazati, da so značilnosti glede zmogljivosti metode enake ali boljše od kriterijev glede zmogljivosti, opredeljenih v standardu EN ISO 16911-1, ter da je treba določiti in poročati o celotni nezanesljivosti metode, izraženo s stopnjo zaupanja 95 %. Rezultati vsake metode, opredeljene v standardu EN ISO 16911-1, imajo različno nezanesljivost znotraj razpona od 1 do 10 % pri hitrostih pretoka 20 m/s. Uporabijo se lahko tudi nadaljnje metode, če lahko uporabnik dokaže enakovrednost, na podlagi načel iz CEN/TS 14793.

General Information

• Status: Published
• Public Enquiry End Date: 19-Jan-2012
• Publication Date: 18-May-2014
• ICS: 13.040.40 - Stationary source emissions
• Technical Committee: KAZ - Air quality
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 07-Apr-2014
• Due Date: 12-Jun-2014
• Completion Date: 19-May-2014
• Directive: 2000/76/EC - Directive 2000/76/EC of the European Parliament and of the Council of 4 December 2000 on the incineration of waste
• Directive: 2001/80/EC - Directive 2001/80/EC of the European Parliament and of the Council of 23 October 2001 on the limitation of emissions of certain pollutants into the air from large combustion plants
• Ref Project: EN ISO 16911-1:2013 - Stationary source emissions - Manual and automatic determination of velocity and volume flow rate in ducts - Part 1: Manual reference method (ISO 16911-1:2013)

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 16911-1:2014
01-julij-2014
(PLVLMHQHSUHPLþQLKYLURY5RþQRLQDYWRPDWVNRGRORþHYDQMHKLWURVWLLQ
YROXPHQVNHJDSUHWRNDYRGYRGQLNLKGHO5RþQDUHIHUHQþQDPHWRGD,62

Stationary source emissions - Manual and automatic determination of velocity and
volume flow rate in ducts - Part 1: Manual reference method (ISO 16911-1:2013)
Emissionen aus stationären Quellen - Manuelle und automatische Bestimmung der
Geschwindigkeit und des Volumenstroms in Abgaskanälen - Teil 1: Manuelles
Referenzverfahren (ISO 16911-1:2013)
Émissions de sources fixes - Détermination manuelle et automatique de la vitesse et du
débit-volume d'écoulement dans les conduits - Partie 1: Méthode de référence manuelle
(ISO 16911-1:2013)
Ta slovenski standard je istoveten z: EN ISO 16911-1:2013
ICS:
13.040.40 (PLVLMHQHSUHPLþQLKYLURY Stationary source emissions
SIST EN ISO 16911-1:2014 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 16911-1:2014

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SIST EN ISO 16911-1:2014


EUROPEAN STANDARD
EN ISO 16911-1

NORME EUROPÉENNE

EUROPÄISCHE NORM
March 2013
ICS 13.040.40
English Version
Stationary source emissions - Manual and automatic
determination of velocity and volume flow rate in ducts - Part 1:
Manual reference method (ISO 16911-1:2013)
Émissions de sources fixes - Détermination manuelle et Emissionen aus stationären Quellen - Manuelle und
automatique de la vitesse et du débit-volume d'écoulement automatische Bestimmung der Geschwindigkeit und des
dans les conduits - Partie 1: Méthode de référence Volumenstroms in Abgaskanälen - Teil 1: Manuelles
manuelle (ISO 16911-1:2013) Referenzverfahren (ISO 16911-1:2013)
This European Standard was approved by CEN on 23 February 2013.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16911-1:2013: E
worldwide for CEN national Members.

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SIST EN ISO 16911-1:2014
EN ISO 16911-1:2013 (E)
Contents Page
Foreword . 3

2

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SIST EN ISO 16911-1:2014
EN ISO 16911-1:2013 (E)
Foreword
This document (EN ISO 16911-1:2013) has been prepared by Technical Committee CEN/TC 264 “Air quality",
the secretariat of which is held by DIN, in collaboration with Technical Committee ISO/TC 146 "Air quality".
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 September 2013, and conflicting national standards shall be
withdrawn at the latest by September 2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
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, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
3

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SIST EN ISO 16911-1:2014

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SIST EN ISO 16911-1:2014
INTERNATIONAL ISO
STANDARD 16911-1
First edition
2013-03-01
Stationary source emissions — Manual
and automatic determination of velocity
and volume flow rate in ducts —
Part 1:
Manual reference method
Émissions de sources fixes — Détermination manuelle et automatique
de la vitesse et du débit-volume d’écoulement dans les conduits —
Partie 1: Méthode de référence manuelle
Reference number
ISO 16911-1:2013(E)
©
ISO 2013

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SIST EN ISO 16911-1:2014
ISO 16911-1:2013(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2013
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
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved

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SIST EN ISO 16911-1:2014
ISO 16911-1:2013(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 3
4.1 Symbols . 3
4.2 Abbreviated terms . 7
5 Principle . 7
5.1 General . 7
5.2 Principle of flow velocity determination at a point in the duct . 8
5.3 Principle of measurement of volume flow rate . 8
6 Selection of monitoring approach .10
6.1 Monitoring objective .10
6.2 Choice of technique to determine point flow velocity .11
6.3 Choice of technique for volume flow rate and average flow determination .12
7 Measuring equipment .12
7.1 General .12
7.2 Measurement of duct area .13
8 Performance characteristics and requirements .13
9 Measurement procedure .14
9.1 Site survey before testing .14
9.2 Determination of sampling plane and number of measurement points .14
9.3 Checks before sampling .14
9.4 Quality control .16
9.5 Measurement of flow at locations within the measurement plane .16
9.6 Post-measurement quality control .17
10 Calculation of results .17
10.1 General .17
10.2 Measurement of velocity .17
10.3 Determination of the mean velocity .18
10.4 Correction of average velocity for wall effects .18
10.5 Calculation of the volume flow rate from the average velocity .18
10.6 Conversion of results to standard conditions.19
11 Establishment of the uncertainty of results .20
12 Evaluation of the method .20
Annex A (normative) Measurement of velocity using differential pressure based techniques .22
Annex B (normative) Vane anemometer .34
Annex C (normative) Tracer gas dilution method determination of volume flow rate and
average velocity .40
Annex D (normative) Transit time tracer gas method determination of average velocity .46
Annex E (normative) Calculation of flue gas volume flow rate from energy consumption .53
Annex F (informative) Example of uncertainty budget established for velocity and volume flow
rate measurements by Pitot tube .61
Annex G (informative) Description of validation studies .72
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Annex H (informative) Differential pressure measurement .79
Annex I (informative) The use of time of flight measurement instruments based on modulated
laser light .82
Annex J (informative) Relationship between this International Standard and the essential
requirements of EU Directives .83
Bibliography .84
iv © ISO 2013 – All rights reserved

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SIST EN ISO 16911-1:2014
ISO 16911-1:2013(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.
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 16911-1 was prepared by the European Committee for Standardization (CEN) in collaboration with
ISO Technical Committee TC 146, Air quality, Subcommittee SC 1, Stationary source emissions.
ISO 16911 consists of the following parts, under the general title Stationary source emissions — Manual
and automatic determination of velocity and volume flow rate in ducts:
— Part 1: Manual reference method
— Part 2: Automated measuring systems
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SIST EN ISO 16911-1:2014
ISO 16911-1:2013(E)

Introduction
EN ISO 16911-1 describes a method for periodic determination of the axial velocity and volume flow rate
of gas within emissions ducts and stacks and for the calibration of automated flow monitoring systems
permanently installed on a stack.
EN ISO 16911-1 provides a method which uses point measurements of the flow velocity to determine
the flow profile and mean and volume flow rates. It also provides for alternative methods based on
tracer gas injection, which can also used to provide routine calibration for automated flow-monitoring
systems. A method based on calculation from energy consumption is also described. EN ISO 16911-1
provides guidance on when these alternative methods may be used.
vi © ISO 2013 – All rights reserved

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SIST EN ISO 16911-1:2014
INTERNATIONAL STANDARD ISO 16911-1:2013(E)
Stationary source emissions — Manual and automatic
determination of velocity and volume flow rate in ducts —
Part 1:
Manual reference method
1 Scope
EN ISO 16911-1 specifies a method for periodic determination of the axial velocity and volume flow rate
of gas within emissions ducts and stacks. It is applicable for use in circular or rectangular ducts with
measurement locations meeting the requirements of EN 15259. Minimum and maximum duct sizes are
driven by practical considerations of the measurement devices described within EN ISO 16911-1.
EN ISO 16911-1 requires all flow measurements to have demonstrable metrological traceability to
national or international primary standards.
To be used as a standard reference method, the user is required to demonstrate that the performance
characteristics of the method are equal to or better than the performance criteria defined in
EN ISO 16911-1 and that the overall uncertainty of the method, expressed with a level of confidence of
95 %, is determined and reported. The results for each method defined in EN ISO 16911-1 have different
uncertainties within a range of 1 % to 10 % at flow velocities of 20 m/s.
Methods further to these can be used provided that the user can demonstrate equivalence, based on the
[10]
principles of CEN/TS 14793.
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.
ISO 20988, Air quality — Guidelines for estimating measurement uncertainty
ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM:1995)
EN 14789, Stationary source emissions — Determination of volume concentration of oxygen (O2) —
Reference method — Paramagnetism
EN 14790, Stationary source emissions — Determination of the water vapour in ducts
EN 15259:2007, Air quality — Measurement of stationary source emissions — Requirements for measurement
sections and sites and for the measurement objective, plan and report
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
© ISO 2013 – All rights reserved 1

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SIST EN ISO 16911-1:2014
ISO 16911-1:2013(E)

3.1
Pitot tube
device to measure flow velocity at a point, operating on the principle of differential pressure measurement
Note 1 to entry: A number of designs of Pitot tube may be used, including standard L-type, S-type, 2D, and 3D Pitot
tubes. Annex A describes a number of Pitot designs currently in use in Europe.
3.2
measurement line
line across the stack, on a measurement plane, along which flow measurements are made to characterize
the flow velocity profile or to determine the average flow
3.3
measurement plane
plane normal to the centreline of the duct at the measurement location at which the measurement of
flow velocity or volume flow rate is required
3.4
measurement point
sampling point
position in the measurement plane at which the sample stream is extracted or the measurement data
are obtained directly
3.5
volume flow rate
volume flow of gas axially along a duct
Note 1 to entry: If not specifically stated, the term may be taken to mean the mean volume flow passing through
the measurement plane.
Note 2 to entry: Volume flow rate is expressed in cubic metres per second or cubic metres per hour.
3.6
point flow velocity
local gas velocity at a point in the duct
Note 1 to entry: Unless otherwise specified, the term may be taken to mean the axial velocity at the
measurement location.
Note 2 to entry: Point flow velocity is expressed in metres per second.
3.7
average flow velocity
<1> velocity which, when multiplied by the area of the measurement
plane of the duct, gives the volume flow rate in that duct
<2> quotient of the volume flow rate in the duct and the area of the measurement plane of the duct
3.8
standard conditions
reference value a pressure 101,325 kPa and a temperature 273,15 K
3.9
uncertainty (of measurement)
parameter, associated with the result of a measurement, that characterizes the dispersion of the values
that could reasonably be attributed to the measurand
2 © ISO 2013 – All rights reserved

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SIST EN ISO 16911-1:2014
ISO 16911-1:2013(E)

3.10
uncertainty budget
statement of a measurement uncertainty, of the components of that measurement uncertainty, and of
their calculation and combination
[5]
Note 1 to entry: For the purposes of EN ISO 16911-1, the sources of uncertainty are according to ISO 14956 or
ISO/IEC Guide 98-3.
3.11
standard uncertainty
uncertainty of the result of a measurement expressed as a standard deviation
3.12
expanded uncertainty
quantity defining an interval about the result of a measurement that may be expected to encompass a
large fraction of the distribution of values that could reasonably be attributed to the measurand
Note 1 to entry: In EN ISO 16911-1, the expanded uncertainty is calculated with a coverage factor of k = 2, and with
a level of confidence of 95 %.
3.13
overall uncertainty
expanded combined standard uncertainty attached to the measurement result
Note 1 to entry: The overall uncertainty is calculated according to ISO/IEC Guide 98-3.
3.14
swirl
cyclonic flow
tangential component of the flow vector providing a measure of the non-axial flow at the measurement plane
3.15
automated measuring system
AMS
measuring system permanently installed on site for continuous monitoring of flow
Note 1 to entry: See EN ISO 16911-2.
3.16
metrological traceability
property of a measurement result whereby the result can be related to a reference through a documented
unbroken chain of calibrations, each contributing to the measurement uncertainty
Note 1 to entry: The elements for confirming metrological traceability are an unbroken metrological traceability
chain to an international measurement standard or a national measurement standard, a documented measurement
uncertainty, documented measurement procedure, accredited technical competence, metrological traceability to
the SI, and calibration intervals
4 Symbols and abbreviated terms
4.1 Symbols
2
A area of the measurement plane m
2
A internal area of the measurement section m
I
2
A cross-sectional area of stack ft
s
B number of component B
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SIST EN ISO 16911-1:2014
ISO 16911-1:2013(E)

a , a angle between sensing holes °
1 2
c constant
d outer tube diameter mm
d stack diameter mm
s
e net specific energy (NSE) of the fuel as received MJ/kg
(N)
e absolute error of measurement
P
F force acting on the vane wheel N
F (i) pitch angle ratio at traverse point i 1
1
F (i) 3D probe velocity calibration coefficient at traverse point i 1
2
−1
f vane frequency s
f velocity factor
v
f wall adjustment factor
WA
i ith measurement point
K coefficient of the Pitot tube which includes the Pitot calibration factor and
constant values relating to the Pitot design
0.5
K conversion factor, 85.49 ft/s[(lb/lb-mol)(inHg)/(R)/(inH 0)]
p 2
non-linear calibration factor dependent on density, ρ , and viscosity, η
0 dyn
K ρ
)
( 0,η
dyn
k coverage factor
L length of the measuring section, i.e. the stack length between the two m
measurement levels
L probe length
p
M molar mass of wet gas effluent kg/mol
M molar mass of component B kg/mol
B
M molar mass of gas, dry basis lb-lb/mol
d
M molar mass of gas, wet basis lb-lb/mol
s
n number of measurement points
P energy production MW
p flue gas pressure kPa
p . p pressures at points P . P
1 5 1 5
p stagnation point pressure Pa
2
p static pressure Pa
3
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SIST EN ISO 16911-1:2014
ISO 16911-1:2013(E)

(p − p ) velocity differential pressure at traverse point i inH O
1 2 i 2
(p − p ) pitch differential pressure at traverse point i inH O
4 5 i 2
p atmospheric pressure inHg
atm
p absolute pressure in the duct, in the measurement section Pa
c
p dynamic pressure on the vane wheel Pa
dyn
p static pressure inH O
g 2
p stack absolute pressure inHg
s
p standard absolute pressure 29.92 inHg
std
average static pressure in the measurement section Pa
p
stat
q tracer mass flow rate kg/s
m,t
3
q volume flow rate m /s
V
3
q dry volume flow rate, under standard conditions of temperature and pres- m /s
V,0d
sure
3
dry volume flow rate, under standard conditions of temperature and pres- m /s
q
V,0d,O
2
sure and on actual oxygen concentration
3
dry volume flow rate, under standard conditions of temperature and pres- m /s
q
V,,0dO ,ref
2
sure, and reference oxygen concentration
3
q stack gas flow rate at sample O content and moisture under standard m /s
2
V,0,O
2
conditions
q average dry-basis stack gas volume flow rate corrected to standard condi- dscf/h
V, sd
tions
q average wet-basis stack gas volume flow rate corrected to standard condi- wscf/h
V, sw
tions
3
q volume flow rate under the conditions of temperature and pressure of the m /s
V,w
duct, on wet gas
R gas constant 8,314 J/(K mol)
r geometry of the vane wheel
Sp
T flue gas temperature K
T temperature of gas in the measurement section K
c
T average absolute stack gas temperature across stack R
s(avg)
T °F stack gas temperature at traverse point i °F
s(i)
T R absolute stack gas temperature at traverse point i R
s(i)
T standard absolute temperature 528 R
std
t transit time of the tracer pulse between the two measurement points s
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SIST EN ISO 16911-1:2014
ISO 16911-1:2013(E)

u(v) uncertainty of measurement of the flow velocity m/s
v start-up velocity m/s
0
v velocity corrected for flow direction m/s
c
ν local velocity at measurement point i m/s
i
v measured velocity m/s
meas
v peripheral velocity, v = ϖr
t t Sp
v axial approach velocity m/s
∞
v
mean velocity m/s
v
mean axial velocity m/s
v
v corrected mean velocity m/s
c
v average of the point velocity measurements m/s
p
w ash yield mass fraction of solid fuel as received
ash
w carbon mass fraction in fuel as received
C
w fuel mass fraction in fuel as received
f
w hydrogen mass fraction in fuel as received
H
w
moisture mass fraction in solid fuel as received
HO
2
w nitrogen mass fraction in fuel as received
N
w oxygen mass fraction in fuel as received
O
w sulfur mass fraction in fuel as received
S
α pitch of blade
Δp differential pressure Pa
average dynamic pressure measured at the point i of the measurement sec- Pa
Δp
i
tion
η thermal efficiency
η dynamic viscosity Pa s
dyn
θ measured angle °
meas
3
ρ density of the gas effluent under ambient conditions of temperature and kg/m
pressure of wet gas
σ standard deviation of the m dynamic pressure measurements in the point i
Δp
i
Φ process heat release MW
(N)F
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SIST EN ISO 16911-1:2014
ISO 16911-1:2013(E)

φ volume fraction of component B volume fraction
B
ϕ
concentration of CO in the gas stream in wet gas % volume
2
CO ,w
2
fraction
ϕ flue gas water content, wet % volume
HO
2
fraction
ϕ flue gas oxygen content, dry % volume
O
2
fraction
ϕ oxygen concentration measured in the duct during the exploration of the % volume
O,d
2
duct on dry gas fraction
ϕ reference oxygen concentration % volume
...