ISO 15713:2006
(Main)Stationary source emissions — Sampling and determination of gaseous fluoride content
Stationary source emissions — Sampling and determination of gaseous fluoride content
ISO 15713:2006 is applicable to the measurement of the gaseous fluorides that are entrained in gases carried in stacks or ducts. The gaseous fluoride content is expressed as a mass of hydrogen fluoride in the stack gas. ISO 15713:2006 is applicable to all stacks emitting gases with fluoride concentrations of below 200 mg/m3. It can be used for higher concentrations, but then the absorption efficiency of the bubblers should be checked before the results can be regarded as valid. The detection limit of the method is estimated as 0,1 mg m-3, based on a sample volume of 0,1 m3. All compounds that are volatile at the filtration temperature and produce soluble fluoride compounds upon reaction with water are measured by this method. The method does not measure fluorocarbons. The concentration of fluoride in the adsorbent solution is then measured using an ion selective electrode. The amount of fluoride measured is then expressed as hydrogen fluoride by convention, though this may not reflect the chemical nature of the compounds, which are measured.
Émissions de sources fixes — Échantillonnage et détermination de la teneur en fluorure gazeux
L'ISO 15713:2006 s'applique au mesurage des fluorures gazeux entraînés dans les gaz véhiculés dans les cheminées ou les conduits. La teneur en fluorure gazeux est exprimée comme la masse de fluorure d'hydrogène contenue dans les gaz du conduit. L'ISO 15713:2006 s'applique à toutes les cheminées émettant des gaz dont les concentrations en fluorure sont inférieures à 200 mg/m3. Elle peut être utilisée pour des concentrations plus élevées mais, dans ce cas, l'efficacité d'absorption des barboteurs devrait être vérifiée avant que les résultats ne puissent être considérés comme valides. La limite de détection de la méthode est estimée à 0,1 mg m-3 pour un échantillon dont le volume est de 0,1 m3. Tous les composés qui sont volatils à la température de filtration et produisent des composés de fluorure solubles dans l'eau sont mesurés à l'aide de cette méthode. Cette méthode ne mesure pas les composés fluorocarbonés. La concentration de fluorure dans la solution adsorbante est alors mesurée à l'aide d'une électrode sélective. La quantité de fluorure mesurée est alors exprimée par convention en équivalent fluorure d'hydrogène, bien qu'il soit possible que cela ne reflète pas la nature chimique des composés qui sont mesurés.
Emisije nepremičnih virov - Vzorčenje in določevanje plinastega fluorida
General Information
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Standards Content (Sample)
INTERNATIONAL ISO
STANDARD 15713
First edition
2006-06-01
Stationary source emissions — Sampling
and determination of gaseous fluoride
content
Émissions de sources fixes — Échantillonnage et détermination de la
teneur en fluorure gazeux
Reference number
ISO 15713:2006(E)
©
ISO 2006
---------------------- Page: 1 ----------------------
ISO 15713:2006(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO 2006
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 2006 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 15713:2006(E)
Contents Page
Foreword. iv
Introduction . iv
1 Scope .1
2 Normative references .1
3 Terms and definitions .1
4 Principle.2
5 Reagents.2
6 Apparatus .3
7 Sampling.5
8 Analytical procedure by ion selective electrode .9
9 Expression of results .11
10 Performance characteristics .13
11 Test report .13
© ISO 2006 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 15713:2006(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 15713 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1, Stationary
source emissions.
iv © ISO 2006 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 15713:2006(E)
Introduction
This International Standard describes a method for the measurement of the concentration of gaseous fluoride
compounds in flue gas passing through ducts or chimneys.
The effects of fluoride containing species are of concern as irritants to humans when inhaled at high
concentration and because of the potential for adverse effects on vegetation.
For the purposes of this International Standard, the fluoride measured is quoted as hydrogen fluoride. The aim
of the method is to measure hydrogen fluoride, but, in practice, the parameter assessed is operationally
defined. The fluoride measured is from those compounds that pass through a filter and dissolve in dilute
sodium hydroxide and which produce fluoride ions which remain present in solution when analysed.
© ISO 2006 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 15713:2006(E)
Stationary source emissions — Sampling and determination of
gaseous fluoride content
1 Scope
This International Standard is applicable to the measurement of the gaseous fluorides that are entrained in
gases carried in stacks or ducts. The gaseous fluoride content is expressed as a mass of hydrogen fluoride in
the stack gas.
This International Standard is applicable to all stacks emitting gases with fluoride concentrations of below
3
200 mg/m . It can be used for higher concentrations, but then the absorption efficiency of the bubblers should
be checked before the results can be regarded as valid. The detection limit of the method is estimated as
−3 3
0,1 mg m , based on a sample volume of 0,1 m . All compounds that are volatile at the filtration temperature
and produce soluble fluoride compounds upon reaction with water are measured by this method. The method
does not measure fluorocarbons. The concentration of fluoride in the adsorbent solution is then measured
using an ion selective electrode. The amount of fluoride measured is then expressed as hydrogen fluoride by
convention, though this may not reflect the chemical nature of the compounds, which are measured.
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 9096:2003, Stationary source emissions — Manual determination of mass concentration of particulate
matter
ISO 10780, Stationary source emissions — Measurement of velocity and volume flowrate of gas streams in
ducts
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
isokinetic sampling
sampling at a flowrate such that the velocity and direction of the gas entering the sampling nozzle is the same
as that of the gas in the duct at the sampling point
[ISO 9096:2003]
3.2
sampling point
specific position on the sampling section at which a sample is extracted
NOTE Sampling points are spread out over the sampling section in order to be representative of subsections of equal
areas.
© ISO 2006 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 15713:2006(E)
3.3
STP
standard conditions for temperature, 273,15 K, and pressure, 101,325 kPa
4 Principle
As a result of the high reactivity and solubility of hydrogen fluoride, particular precautions are required to
minimize irreversible loss of the species of interest and to take a representative sample. Firstly, if incorrect
materials are selected for the sampling probe, impingers and connecting tubing they could react irreversibly
with the species of interest. Secondly, if condensed liquid droplets are present in the probe before the
impingers the species of interest may dissolve in them and so not be included in the measurement. Further,
where droplets are present in the flue, if the sample is not taken isokinetically, then it may not be
representative.
The flow conditions at a sampling plane are determined before sampling. If there are droplets present, then
isokinetic sampling at a number of sampling points is necessary. The homogeneity of the spatial profiles of the
flue gas velocity, temperature and oxygen concentration is investigated. If there is significant variability in any
of these parameters, but no droplets, then sampling is carried out at a number of sampling points but at a
constant flow rate. If these parameters exhibit homogeneity, then sampling is carried out at a single point at a
constant flow rate.
To determine the gaseous fluoride content of the flue gas, a representative metered sample of that gas is
drawn through a heated sampling probe and filter. Any droplets, which may contain dissolved gaseous fluoride
compounds, are evaporated in the heated probe. Particulate bound fluoride species that may be present as
solid materials are removed by filtration of particulates at a controlled temperature. Gaseous fluoride
compounds or more precisely those water-soluble fluoride compounds that pass through the filter are
absorbed using a sampling train made up of a series of impingers containing a sodium hydroxide solution.
The concentrations of dissolved fluoride ions in the collected solutions are measured using the ion selective
electrode technique.
5 Reagents
To carry out the method, the following reagents are required to be of a recognized analytical grade. If they
have changed visibly, they should be discarded.
5.1 Absorber solution, 0,1 mol/l NaOH solution.
5.2 Sample gas drying agent, self-indicating coarse grade silica gel.
5.3 Total ionic strength adjustment buffer (TISAB).
Sodium chloride
Sodium acetate trihydrate
Trisodium citrate monohydrate
Glacial acetic acid
Deionized or distilled water
5,0 mol/l NaOH
2 © ISO 2006 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 15713:2006(E)
5.4 Calibration solutions.
Deionized or distilled water
Sodium fluoride
6 Apparatus
6.1 Introduction
A schematic diagram of the equipment for the sampling of gaseous fluorides is given in Figure 1. The
apparatus consists of a sampling probe and filter assembly that may be heated if required, an impinger train
containing sodium hydroxide solution to capture gaseous fluorides, a pressure gauge, a suction control valve,
a suction pump, a gas meter, and a sample gas volume flow rate measurement system. A thermometer and
manometer shall be included in the sample train to allow the temperature and relative pressure of the metered
gas to be determined. A barometer shall be used to measure atmospheric pressure during the test in order
that the volume of the gas sampled can be normalized to standard conditions of 273,15 K and 101,325 kPa.
6.2 Probe
The probe shall be a length of rigid tubing and shall be capable of withstanding the temperature within the
duct. It shall be resistant to chemical attack from the various pollutants in the duct. In particular, the probe
shall be resistant to fluoride attack to avoid sample loss. Suitable materials for fluoride sampling are silica or
® 1)
Monel type alloys .
The probe shall have a heating system capable of maintaining a gas temperature at its exit of at least 423 K or
> 20 K ± 5 K above the dew point temperature, whichever is the higher.
The internal surfaces of the sample probe shall be cleaned thoroughly before each sample run by rinsing it
with deionized water. Between samples, it will first be necessary to allow the probe to cool. The probe rinse
shall be repeated until the rinse water shows no evidence of particulate matter.
6.3 Filter and filter housing
A filter shall be used to capture particulate material to prevent dissolution of any soluble particulate fluoride.
Filters can be placed in the duct between the nozzle and the probe only if there are no droplets present, or out
of the duct before the first impinger. If a filter is used outside the duct, it shall be heated to a temperature of at
least 423 K or > 20 K ± 5 K above the dew point temperature, whichever is the higher, to avoid condensation.
If the amount of particulate fluoride within the sample is below 10 % of the total, then the filter can be omitted.
Filters and filter holders shall be made of material resistant to attack by fluorides; for example, glass frits will
remove gaseous fluoride and therefore cannot be used as filter supports. Filter holders shall have an airtight
seal against leakage from outside or around the filter.
The filter shall be capable of withstanding prolonged exposures up to 40 K above the temperature setting and
have at least 99,5 % collection efficiency for 0,3 µm diameter particles.
The filter housing shall be cleaned thoroughly prior to use and before each sample run using deionized
distilled water until no particulate matter is present on the inner surfaces of the filter holder.
®
1) Monel type alloys is an example of a suitable product(s) available commercially. This information is given for the
convenience of users of this International Standard and does not constitute an endorsement by ISO of this product.
© ISO 2006 – All rights reserved 3
---------------------- Page: 8 ----------------------
ISO 15713:2006(E)
6.4 Sampling train
The impingers shall be connected to the sampling probe using HF resistant materials. Suitable materials are
® 2)
polypropylene, polyethylene or Viton tubing . The sampling train consists of a series of four impingers
through which the sample gases are passed and the fluorides are removed into solution. The impingers can
be made of quartz, polypropylene or polyethylene. Convenient sizes for impingers are 125 ml to 250 ml.
The first two impingers shall contain between 50 ml and 100 ml of 0,1 mol/l NaOH solution of analytical grade.
The third impinger shall be left empty to catch any carryover of the absorption solution.
The fourth impinger shall be used a drying unit. Its materials of construction need not be resistant to HF. It
shall be filled with silica gel to dry the sample gas prior to the suction unit, gas meter and volume flow meter.
Prior to use, the impingers shall all be rinsed and cleaned with distilled or deionized water and a bottlebrush.
During sampling, the gases shall enter the first impinger at its base and bubble up through the sodium
hydroxide solution before entering the second impinger at its base.
The geometry of the impingers and quantity of absorbing solution employed shall be such that a gaseous
fluoride absorbance efficiency of not less than 95 % is achieved at the chosen sampling flow rate and in the
concentration range examined. Evidence that this criteria is met shall be demonstrated on at least one
occasion at the maximum flow rate used with that design of equipment.
6.5 Suction unit
The pump is used to draw the sample through the sampling train. It shall be an airtight pump capable of
maintaining the selected sampling flow rate throughout the sampling period and shall be adjusted using a flow
regulator.
6.6 Thermometer
An airtight thermometer shall be fitted into the sample line after the drying unit and before the gas meter. The
thermometer shall be capable of measuring absolute temperature to within 1 % of the absolute temperature.
6.7 Differential pressure gauge
The differential pressure gauge shall be used to measure the difference in pressure between the gas entering
the volume meter and atmospheric pressure. It shall be capable of measuring pressure difference to within 1%
of the differential pressure.
6.8 Gas volume meter
The volume of the dried sample gas shall be measured using a calibrated gas meter. The gas meter shall be
capable of measuring the sampled gas volume to within 2 % of the actual volume.
6.9 Sample gas flow rate meter
A flow rate meter shall be used to ensure that the sample flow rate stays within the limits specified in section
6.4 and to perform the actions described in 7.5, 7.7 and 7.8. This meter shall be capable of measuring the flow
rate to within ± 10 % of the flow.
6.10 Barometer
A barometer shall be used to measure the local atmospheric pressure in kilopascals (kPa) to within 1 % of the
absolute pressure.
®
2) Viton tubing is an example of a suitable product(s) available commercially. This information is given for the
convenience of users of this International Standard and does not constitute an endorsement by ISO of this product.
4 © ISO 2006 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 15713:2006(E)
6.11 Working platform
A safe working platform shall be provided at the sampling position so that all the sampling points can be
reached with safety.
7 Sampling
7.1 Sampling position and sampling points
The sampling position shall comprise of suitable access port(s) through which the sampling probe can be
passed into the duct. The port(s) shall be capable of being sealed when not in use. Sampling can be
performed either isokinetically (if droplets are present) or non-isokinetically at points according to the relevant
requirements of ISO 9096. Multipoint sampling at a constant flow rate shall be carried at according to the
relevant requirements of ISO 9096. Sampling will normally be carried out on at least two duct diameters and at
a number of sampling points on each line.
Where this is not possible, due to constraints of either duct design or safety considerations, the sampling
plane shall be situated in a length of straight duct, preferably vertical with a constant shape and constant
cross-sectional area. It shall be as far as practicable downstream from any obstruction that may cause a
disturbance or produce a change in the flow (for example, a bend, a fan or a damper).
The position at which a representative sample of the gas is to be taken is an important part of the sampling
procedure. Representative sampling requires the gas to be taken from a homogenous flow in the duct. To
achieve this, the velocity, temperature, and the oxygen concentration, shall first be determined at
representative sampling points across the chosen sampling plane. The object of this procedure is to confirm
that the velocity profile conforms to the requirement of ISO 9096. The temperature and oxygen shall not vary
across the duct by more than 5 % from the mean value to avoid stratification affecting the measured
concentration. If no stratification is detected, then a representative location shall be chosen for sampling.
7.2 Minimum sampling duration and minimum sample volume
The minimum sampling period and number of samples taken will depend on the nature of the process that is
producing the emissions. The sampling duration shall be at least 30 min. If emissions from a cyclical process
are to be measured, the total sampling period shall cover at least one cycle of the process operation.
The minimum sampling time also needs to take into account the detection limit of the sampling and analytical
method. If the process is operating under steady state conditions, the minimum sampling time and volume can
be calculated prior to sampling, by using the expected emitted gas concentration or a tenth of the emission
limit value if appropriate and the sample train detection limits given in 10.1. If multiple point sampling is
employed, the minimum sampling time at any one point shall not be less than 3 min.
7.3 Number and location of sampling points
An appropriate representative location shall be chosen for sampling. The number and location of the sampling
points on the sampling plane shall conform to ISO 9096, unless this is not practicable.
Sampling at a single point shall only be acceptable if the flue gas velocity, temperature, and oxygen
concentrations meet the requirements stated in 7.1.
If sampling from a number of points is required, then the sampling time chosen shall be the same at each
sample point.
© ISO 2006 – All rights reserved 5
---------------------- Page: 10 ----------------------
ISO 15713:2006(E)
7.4 Other measurements to be made prior to sampling
7.4.1 Volumetric gas flow through duct at the sampling plane
The measurement of the volumetric gas flow through the duct at the sampling plane will be necessary if the
results are to be reported in terms of mass of pollutant emitted per unit t
...
SLOVENSKI STANDARD
SIST ISO 15713:2009
01-marec-2009
(PLVLMHQHSUHPLþQLKYLURY9]RUþHQMHLQGRORþHYDQMHSOLQDVWHJDIOXRULGD
Stationary source emissions - Sampling and determination of gaseous fluoride content
Émissions de sources fixes - Échantillonnage et détermination de la teneur en fluorure
gazeux
Ta slovenski standard je istoveten z: ISO 15713:2006
ICS:
13.040.40 (PLVLMHQHSUHPLþQLKYLURY Stationary source emissions
SIST ISO 15713:2009 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST ISO 15713:2009
---------------------- Page: 2 ----------------------
SIST ISO 15713:2009
INTERNATIONAL ISO
STANDARD 15713
First edition
2006-06-01
Stationary source emissions — Sampling
and determination of gaseous fluoride
content
Émissions de sources fixes — Échantillonnage et détermination de la
teneur en fluorure gazeux
Reference number
ISO 15713:2006(E)
©
ISO 2006
---------------------- Page: 3 ----------------------
SIST ISO 15713:2009
ISO 15713:2006(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
© ISO 2006
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 2006 – All rights reserved
---------------------- Page: 4 ----------------------
SIST ISO 15713:2009
ISO 15713:2006(E)
Contents Page
Foreword. iv
Introduction . iv
1 Scope .1
2 Normative references .1
3 Terms and definitions .1
4 Principle.2
5 Reagents.2
6 Apparatus .3
7 Sampling.5
8 Analytical procedure by ion selective electrode .9
9 Expression of results .11
10 Performance characteristics .13
11 Test report .13
© ISO 2006 – All rights reserved iii
---------------------- Page: 5 ----------------------
SIST ISO 15713:2009
ISO 15713:2006(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 15713 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1, Stationary
source emissions.
iv © ISO 2006 – All rights reserved
---------------------- Page: 6 ----------------------
SIST ISO 15713:2009
ISO 15713:2006(E)
Introduction
This International Standard describes a method for the measurement of the concentration of gaseous fluoride
compounds in flue gas passing through ducts or chimneys.
The effects of fluoride containing species are of concern as irritants to humans when inhaled at high
concentration and because of the potential for adverse effects on vegetation.
For the purposes of this International Standard, the fluoride measured is quoted as hydrogen fluoride. The aim
of the method is to measure hydrogen fluoride, but, in practice, the parameter assessed is operationally
defined. The fluoride measured is from those compounds that pass through a filter and dissolve in dilute
sodium hydroxide and which produce fluoride ions which remain present in solution when analysed.
© ISO 2006 – All rights reserved v
---------------------- Page: 7 ----------------------
SIST ISO 15713:2009
---------------------- Page: 8 ----------------------
SIST ISO 15713:2009
INTERNATIONAL STANDARD ISO 15713:2006(E)
Stationary source emissions — Sampling and determination of
gaseous fluoride content
1 Scope
This International Standard is applicable to the measurement of the gaseous fluorides that are entrained in
gases carried in stacks or ducts. The gaseous fluoride content is expressed as a mass of hydrogen fluoride in
the stack gas.
This International Standard is applicable to all stacks emitting gases with fluoride concentrations of below
3
200 mg/m . It can be used for higher concentrations, but then the absorption efficiency of the bubblers should
be checked before the results can be regarded as valid. The detection limit of the method is estimated as
−3 3
0,1 mg m , based on a sample volume of 0,1 m . All compounds that are volatile at the filtration temperature
and produce soluble fluoride compounds upon reaction with water are measured by this method. The method
does not measure fluorocarbons. The concentration of fluoride in the adsorbent solution is then measured
using an ion selective electrode. The amount of fluoride measured is then expressed as hydrogen fluoride by
convention, though this may not reflect the chemical nature of the compounds, which are measured.
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 9096:2003, Stationary source emissions — Manual determination of mass concentration of particulate
matter
ISO 10780, Stationary source emissions — Measurement of velocity and volume flowrate of gas streams in
ducts
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
isokinetic sampling
sampling at a flowrate such that the velocity and direction of the gas entering the sampling nozzle is the same
as that of the gas in the duct at the sampling point
[ISO 9096:2003]
3.2
sampling point
specific position on the sampling section at which a sample is extracted
NOTE Sampling points are spread out over the sampling section in order to be representative of subsections of equal
areas.
© ISO 2006 – All rights reserved 1
---------------------- Page: 9 ----------------------
SIST ISO 15713:2009
ISO 15713:2006(E)
3.3
STP
standard conditions for temperature, 273,15 K, and pressure, 101,325 kPa
4 Principle
As a result of the high reactivity and solubility of hydrogen fluoride, particular precautions are required to
minimize irreversible loss of the species of interest and to take a representative sample. Firstly, if incorrect
materials are selected for the sampling probe, impingers and connecting tubing they could react irreversibly
with the species of interest. Secondly, if condensed liquid droplets are present in the probe before the
impingers the species of interest may dissolve in them and so not be included in the measurement. Further,
where droplets are present in the flue, if the sample is not taken isokinetically, then it may not be
representative.
The flow conditions at a sampling plane are determined before sampling. If there are droplets present, then
isokinetic sampling at a number of sampling points is necessary. The homogeneity of the spatial profiles of the
flue gas velocity, temperature and oxygen concentration is investigated. If there is significant variability in any
of these parameters, but no droplets, then sampling is carried out at a number of sampling points but at a
constant flow rate. If these parameters exhibit homogeneity, then sampling is carried out at a single point at a
constant flow rate.
To determine the gaseous fluoride content of the flue gas, a representative metered sample of that gas is
drawn through a heated sampling probe and filter. Any droplets, which may contain dissolved gaseous fluoride
compounds, are evaporated in the heated probe. Particulate bound fluoride species that may be present as
solid materials are removed by filtration of particulates at a controlled temperature. Gaseous fluoride
compounds or more precisely those water-soluble fluoride compounds that pass through the filter are
absorbed using a sampling train made up of a series of impingers containing a sodium hydroxide solution.
The concentrations of dissolved fluoride ions in the collected solutions are measured using the ion selective
electrode technique.
5 Reagents
To carry out the method, the following reagents are required to be of a recognized analytical grade. If they
have changed visibly, they should be discarded.
5.1 Absorber solution, 0,1 mol/l NaOH solution.
5.2 Sample gas drying agent, self-indicating coarse grade silica gel.
5.3 Total ionic strength adjustment buffer (TISAB).
Sodium chloride
Sodium acetate trihydrate
Trisodium citrate monohydrate
Glacial acetic acid
Deionized or distilled water
5,0 mol/l NaOH
2 © ISO 2006 – All rights reserved
---------------------- Page: 10 ----------------------
SIST ISO 15713:2009
ISO 15713:2006(E)
5.4 Calibration solutions.
Deionized or distilled water
Sodium fluoride
6 Apparatus
6.1 Introduction
A schematic diagram of the equipment for the sampling of gaseous fluorides is given in Figure 1. The
apparatus consists of a sampling probe and filter assembly that may be heated if required, an impinger train
containing sodium hydroxide solution to capture gaseous fluorides, a pressure gauge, a suction control valve,
a suction pump, a gas meter, and a sample gas volume flow rate measurement system. A thermometer and
manometer shall be included in the sample train to allow the temperature and relative pressure of the metered
gas to be determined. A barometer shall be used to measure atmospheric pressure during the test in order
that the volume of the gas sampled can be normalized to standard conditions of 273,15 K and 101,325 kPa.
6.2 Probe
The probe shall be a length of rigid tubing and shall be capable of withstanding the temperature within the
duct. It shall be resistant to chemical attack from the various pollutants in the duct. In particular, the probe
shall be resistant to fluoride attack to avoid sample loss. Suitable materials for fluoride sampling are silica or
® 1)
Monel type alloys .
The probe shall have a heating system capable of maintaining a gas temperature at its exit of at least 423 K or
> 20 K ± 5 K above the dew point temperature, whichever is the higher.
The internal surfaces of the sample probe shall be cleaned thoroughly before each sample run by rinsing it
with deionized water. Between samples, it will first be necessary to allow the probe to cool. The probe rinse
shall be repeated until the rinse water shows no evidence of particulate matter.
6.3 Filter and filter housing
A filter shall be used to capture particulate material to prevent dissolution of any soluble particulate fluoride.
Filters can be placed in the duct between the nozzle and the probe only if there are no droplets present, or out
of the duct before the first impinger. If a filter is used outside the duct, it shall be heated to a temperature of at
least 423 K or > 20 K ± 5 K above the dew point temperature, whichever is the higher, to avoid condensation.
If the amount of particulate fluoride within the sample is below 10 % of the total, then the filter can be omitted.
Filters and filter holders shall be made of material resistant to attack by fluorides; for example, glass frits will
remove gaseous fluoride and therefore cannot be used as filter supports. Filter holders shall have an airtight
seal against leakage from outside or around the filter.
The filter shall be capable of withstanding prolonged exposures up to 40 K above the temperature setting and
have at least 99,5 % collection efficiency for 0,3 µm diameter particles.
The filter housing shall be cleaned thoroughly prior to use and before each sample run using deionized
distilled water until no particulate matter is present on the inner surfaces of the filter holder.
®
1) Monel type alloys is an example of a suitable product(s) available commercially. This information is given for the
convenience of users of this International Standard and does not constitute an endorsement by ISO of this product.
© ISO 2006 – All rights reserved 3
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SIST ISO 15713:2009
ISO 15713:2006(E)
6.4 Sampling train
The impingers shall be connected to the sampling probe using HF resistant materials. Suitable materials are
® 2)
polypropylene, polyethylene or Viton tubing . The sampling train consists of a series of four impingers
through which the sample gases are passed and the fluorides are removed into solution. The impingers can
be made of quartz, polypropylene or polyethylene. Convenient sizes for impingers are 125 ml to 250 ml.
The first two impingers shall contain between 50 ml and 100 ml of 0,1 mol/l NaOH solution of analytical grade.
The third impinger shall be left empty to catch any carryover of the absorption solution.
The fourth impinger shall be used a drying unit. Its materials of construction need not be resistant to HF. It
shall be filled with silica gel to dry the sample gas prior to the suction unit, gas meter and volume flow meter.
Prior to use, the impingers shall all be rinsed and cleaned with distilled or deionized water and a bottlebrush.
During sampling, the gases shall enter the first impinger at its base and bubble up through the sodium
hydroxide solution before entering the second impinger at its base.
The geometry of the impingers and quantity of absorbing solution employed shall be such that a gaseous
fluoride absorbance efficiency of not less than 95 % is achieved at the chosen sampling flow rate and in the
concentration range examined. Evidence that this criteria is met shall be demonstrated on at least one
occasion at the maximum flow rate used with that design of equipment.
6.5 Suction unit
The pump is used to draw the sample through the sampling train. It shall be an airtight pump capable of
maintaining the selected sampling flow rate throughout the sampling period and shall be adjusted using a flow
regulator.
6.6 Thermometer
An airtight thermometer shall be fitted into the sample line after the drying unit and before the gas meter. The
thermometer shall be capable of measuring absolute temperature to within 1 % of the absolute temperature.
6.7 Differential pressure gauge
The differential pressure gauge shall be used to measure the difference in pressure between the gas entering
the volume meter and atmospheric pressure. It shall be capable of measuring pressure difference to within 1%
of the differential pressure.
6.8 Gas volume meter
The volume of the dried sample gas shall be measured using a calibrated gas meter. The gas meter shall be
capable of measuring the sampled gas volume to within 2 % of the actual volume.
6.9 Sample gas flow rate meter
A flow rate meter shall be used to ensure that the sample flow rate stays within the limits specified in section
6.4 and to perform the actions described in 7.5, 7.7 and 7.8. This meter shall be capable of measuring the flow
rate to within ± 10 % of the flow.
6.10 Barometer
A barometer shall be used to measure the local atmospheric pressure in kilopascals (kPa) to within 1 % of the
absolute pressure.
®
2) Viton tubing is an example of a suitable product(s) available commercially. This information is given for the
convenience of users of this International Standard and does not constitute an endorsement by ISO of this product.
4 © ISO 2006 – All rights reserved
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SIST ISO 15713:2009
ISO 15713:2006(E)
6.11 Working platform
A safe working platform shall be provided at the sampling position so that all the sampling points can be
reached with safety.
7 Sampling
7.1 Sampling position and sampling points
The sampling position shall comprise of suitable access port(s) through which the sampling probe can be
passed into the duct. The port(s) shall be capable of being sealed when not in use. Sampling can be
performed either isokinetically (if droplets are present) or non-isokinetically at points according to the relevant
requirements of ISO 9096. Multipoint sampling at a constant flow rate shall be carried at according to the
relevant requirements of ISO 9096. Sampling will normally be carried out on at least two duct diameters and at
a number of sampling points on each line.
Where this is not possible, due to constraints of either duct design or safety considerations, the sampling
plane shall be situated in a length of straight duct, preferably vertical with a constant shape and constant
cross-sectional area. It shall be as far as practicable downstream from any obstruction that may cause a
disturbance or produce a change in the flow (for example, a bend, a fan or a damper).
The position at which a representative sample of the gas is to be taken is an important part of the sampling
procedure. Representative sampling requires the gas to be taken from a homogenous flow in the duct. To
achieve this, the velocity, temperature, and the oxygen concentration, shall first be determined at
representative sampling points across the chosen sampling plane. The object of this procedure is to confirm
that the velocity profile conforms to the requirement of ISO 9096. The temperature and oxygen shall not vary
across the duct by more than 5 % from the mean value to avoid stratification affecting the measured
concentration. If no stratification is detected, then a representative location shall be chosen for sampling.
7.2 Minimum sampling duration and minimum sample volume
The minimum sampling period and number of samples taken will depend on the nature of the process that is
producing the emissions. The sampling duration shall be at least 30 min. If emissions from a cyclical process
are to be measured, the total sampling period shall cover at least one cycle of the process operation.
The minimum sampling time also needs to take into account the detection limit of the sampling and analytical
method. If the process is operating under steady state conditions, the minimum sampling time and volume can
be calculated prior to sampling, by using the expected emitted gas concentration or a tenth of the emission
limit value if appropriate and the sample train detection limits given in 10.1. If multiple point sampling is
employed, the minimum sampling time at any one point shall not be less than 3 min.
7.3 Number and location of sampling points
An appropriate representative location shall be chosen for sampling. The number and location of the sampling
points on the sampling plane shall conform to ISO 9096, unless this is not practicable.
Sampling at a single point shall only be acceptable if the flue gas velocity, temperature, and oxygen
concentrations meet the requirements stated in 7.1.
If sampling from a number of points is required, then the sampling time chosen shall be the same at each
sample point.
© ISO 2006 – All rights reserved 5
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SIST ISO 15713:2009
ISO 15713:2006(E)
7.4 Other measurements to be made prior to sampling
7.4.1 Volumetric gas flow through duct at the sampling plane
The measurement of the volumetric gas flow through the duct at the sampling plane will be necessary if the
results are to be reported in terms of mass of pollutant emitted per unit time. The measurements shall be
carried out in accordance with ISO 10780.
7.4.2 Moisture content of gas
The measurement of the moisture content of the gas will be necessary if the results are to be reported as a
fluoride concentration on a wet basis or if the sampling is to be carried out isokinetically.
7.4.3 Oxygen content of gas
If sampling is to be carried out of emissions from a combustion plant and the results are to be reported after
correction to a particular oxygen concentration, measurement of the flue gas oxygen concentration will be
necessary during the sampling period.
7.5 Assembly of sampling apparatus
Sampling is carried out with the apparatus assembled as illustrated in Figure 1.
NOTE The filter can be positioned in the duct or out of the duct before the first impinger (see 6.3).
Preheat all relevant parts of the sampling train and insert the probe into the duct, so that the sampling tip is
positioned at the first sampling point. Avoid contact between the probe and any deposits in the duct or
sampling port. Seal the opening of the access port to minimize air in-leakage.
7.6 Sampling
If the sampling is to be carried out isokinetically, this shall be done according to the relevant requirements of
ISO 9096.
If sampling is to be carried out at multiple sampling positions, this shall be done according to the relevant
requirements of ISO 9096.
Otherwise, record the time and the current gas meter reading, then start the pump. Set the sampling flow rate
to the desired level using the suction control valve and the flow rate meter. The sampling rate shall be
sufficient to allow vigorous bubbling within the first two impingers of the sampling train but not so vigorous that
the solution is carried over into the third empty impinger. A constant sampling flow rate shall be maintained at
each point (to within ± 10 % of the chosen rate). Meter temperature and pressure should be recorded
periodically. If more than one sampling point is employed on a sampling line, then move the sampling probe
directly to the next point once the sampling period at that point is complete — do not switch off the pump. In
this way, complete the sampling operations at all points on one line. If another line is to be employed, the
suction control valve shall be closed at the end of sampling on the first line and the sampling pump switched
off. The gas meter should be read and sampling operations carried out on the second line as before.
At the end of the final sampling period, the suction control valve shall be closed and the sampling pump
switched off. The gas meter shall be read. A leak test of the equipment should then be carried out.
NOTE A sample rate of between 2 l/min and 6 l/min may be sufficient to allow vigorous bubbling.
6 © ISO 2006 – All rights reserved
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SIST ISO 15713:2009
ISO 15713:2006(E)
Key
1 heated probe
2 filter and housing
3 0,1 molar NaOH impingers
4 catchpot
5 drying tube or silica gel dreschel
6 pump
7 temperature and pressure gauges
8 gas meter
9 rotameter
Figure 1 — Schematic diagram of a sampling train
7.7 Leak-check procedure
A pre-test leak-check is required before and after all sampling and also if any of the sampling train
components are replaced during a test. The leak rate shall not exceed 2 % of the nominal sample gas flow
rate to be used.
7.8 Leak-checks during sample run
If, during the sampling run, a component (e.g. filter assembly or impinger) change becomes necessary, a leak
check shall be conducted immediately before the change is made. The leak-check shall be carried out as the
initial leak check, except that it shall be done at a vacuum equal to or greater to the maximum value recorded
up to that point in the test. If the leakage rate is found to be no greater than 2 % of the average sampling rate,
the results are acceptable. If a higher leakage rate is measured, the sample is void.
7.9 Post-test leak-check
A leak-check is mandatory at the conclusion of each sampling run. The leak-check shall be carried out as the
initial leak check, except that it shall be conducted at a vacuum equal to or greater than the maximum value
reached during the sampling run. If the leakage rate is found to be no greater than 2 % of the average
sampling rate, the results are acceptable. If a higher leakage rate is measured, the sample is void.
© ISO 2006 – All rights reserved 7
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SIST ISO 15713:2009
ISO 15713:2006(E)
7.10 Quality assurance
Prior to sampling make a note of the time and the current gas meter reading. During sampling, the flow rate of
the sample gas shall be noted periodically, together with the temperature and pressure at the gas meter to
allow the calculation of the average temperature and pressure during the sampling period.
During sampling, operatives shall periodically check and correct the following:
⎯ that the flow rate has not drifted by more than ± 10 % of the chosen flow rate;
⎯ that the silica gel has not been exhausted. If the colour of the silica gel indicates that it is nearly
exhausted, then the pump shall be switched off and the sampler withdrawn from the duct to be leak
tested while a new bottle of silica gel is fitted into the system.
If any of the components are replaced, then the leak test shall be performed again.
The leak rate measured during any leak test shall not be greater than 4 % of the nominal flow rate. If the leak
rate is greater than this, then the concentration measured will be an underestimate of the true value. If the
measured concentrations are above the appropriate limit value then the result can be used as a lower
estimate of the true concentration in the flue gas. However, in other circumstances, the result is invalid.
7.11 Sample recovery
Analysis of the particulate bound fluorides on the filter is not required by this International Standard and so it
may be discarded.
The fluorides contained in the impingers shall be carefully recovered as soon as possible.
Withdraw the probe from the stack and allow it to cool so that it can be handled.
Wipe off all external particulate matter near the tip of the probe.
If a filter following the probe was used, then disconnect the probe from the sampling train and check to see if
there is any condensation present within the probe. If there is evidence of condensation, the test shall be
rejected. The contents of the three impingers shall be carefully poured into a sample container, each impinger
shall be rinsed with approximately 20 ml of deionized distilled water, and these washings shall be added to a
sample container. Repeat the process for each impinger. If the adsorption efficiency of the sampler is being
determined, the impinger solutions shou
...
NORME ISO
INTERNATIONALE 15713
Première édition
2006-06-01
Émissions de sources fixes —
Échantillonnage et détermination de la
teneur en fluorure gazeux
Stationary source emissions — Sampling and determination of gaseous
fluoride content
Numéro de référence
ISO 15713:2006(F)
©
ISO 2006
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ISO 15713:2006(F)
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Publié en Suisse
ii © ISO 2006 – Tous droits réservés
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ISO 15713:2006(F)
Sommaire Page
Avant-propos. iv
Introduction . v
1 Domaine d'application. 1
2 Références normatives . 1
3 Termes et définitions. 1
4 Principe. 2
5 Réactifs . 2
6 Appareillage . 3
7 Échantillonnage . 5
8 Méthode analytique par électrode sélective .9
9 Expression des résultats . 11
10 Caractéristiques de performance. 14
11 Rapport d'essai . 14
© ISO 2006 – Tous droits réservés iii
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ISO 15713:2006(F)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux de
normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général confiée
aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du
comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI,
Partie 2.
La tâche principale des comités techniques est d'élaborer les Normes internationales. Les projets de Normes
internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur
publication comme Normes internationales requiert l'approbation de 75 % au moins des comités membres
votants.
L'attention est appelée sur le fait que certains des éléments du présent document peuvent faire l'objet de
droits de propriété intellectuelle ou de droits analogues. L'ISO ne saurait être tenue pour responsable de ne
pas avoir identifié de tels droits de propriété et averti de leur existence.
L'ISO 15713 a été élaborée par le comité technique ISO/TC 146, Qualité de l'air, sous-comité SC 1,
Émissions de sources fixes.
iv © ISO 2006 – Tous droits réservés
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ISO 15713:2006(F)
Introduction
La présente Norme internationale décrit une méthode permettant de mesurer la concentration en composés
de fluorure gazeux dans les effluents gazeux qui passent par les conduits ou les cheminées.
Les effets des espèces contenant du fluorure sont préoccupants dans la mesure où le fluorure est irritant pour
l'homme lorsqu'il est inhalé à des concentrations élevées et où il peut avoir des effets phytosanitaires néfastes.
Pour les besoins de la présente Norme internationale, le fluorure mesuré est exprimé en équivalent fluorure
d'hydrogène. Cette méthode a pour but de mesurer le fluorure d'hydrogène mais, en pratique, le paramètre
évalué est défini par calcul. Le fluorure mesuré est de ces composés qui traversent un filtre, se dissolvent
dans de l'hydroxyde de sodium dilué et produisent des ions fluorures qui restent présents dans la solution
lorsqu'elle est analysée.
© ISO 2006 – Tous droits réservés v
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NORME INTERNATIONALE ISO 15713:2006(F)
Émissions de sources fixes — Échantillonnage et détermination
de la teneur en fluorure gazeux
1 Domaine d'application
La présente Norme internationale s'applique au mesurage des fluorures gazeux entraînés dans les gaz
véhiculés dans les cheminées ou les conduits. La teneur en fluorure gazeux est exprimée comme la masse
de fluorure d'hydrogène contenue dans les gaz du conduit.
La présente Norme internationale s'applique à toutes les cheminées émettant des gaz dont les concentrations
3
en fluorure sont inférieures à 200 mg/m . Elle peut être utilisée pour des concentrations plus élevées mais,
dans ce cas, l'efficacité d'absorption des barboteurs devrait être vérifiée avant que les résultats ne puissent
−3
être considérés comme valides. La limite de détection de la méthode est estimée à 0,1 mg m pour un
3
échantillon dont le volume est de 0,1 m . Tous les composés qui sont volatils à la température de filtration et
produisent des composés de fluorure solubles dans l'eau sont mesurés à l'aide de cette méthode. Cette
méthode ne mesure pas les composés fluorocarbonés. La concentration de fluorure dans la solution
adsorbante est alors mesurée à l'aide d'une électrode sélective. La quantité de fluorure mesurée est alors
exprimée par convention en équivalent fluorure d'hydrogène, bien qu'il soit possible que cela ne reflète pas la
nature chimique des composés qui sont mesurés.
2 Références normatives
Les documents de référence suivants sont indispensables pour l'application du présent document. Pour les
références datées, seule l'édition citée s'applique. Pour les références non datées, la dernière édition du
document de référence (y compris les éventuels amendements) s'applique.
ISO 9096:2003, Émissions de sources fixes — Détermination manuelle de la concentration en masse de
poussières
ISO 10780, Émissions de sources fixes — Mesurage de la vitesse et du débit-volume des courants gazeux
dans des conduites
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s'appliquent.
3.1
prélèvement isocinétique
prélèvement effectué à un débit donné tel que la vitesse et le sens du gaz entrant dans la buse de
prélèvement sont identiques à la vitesse et au sens du gaz «dans le conduit» au point de prélèvement
[ISO 9096: 2003]
3.2
point de prélèvement
position spécifique sur la section de prélèvement d'où est extrait l'échantillon
NOTE Les points de prélèvements sont disséminés sur la section de prélèvement de façon à être représentatifs de
sous-sections d'aires égales.
© ISO 2006 – Tous droits réservés 1
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ISO 15713:2006(F)
3.3
NTP
conditions normales de température (273,15 K) et de pression (101,325 kPa)
4 Principe
En raison de la réactivité et de la solubilité élevées du fluorure d'hydrogène, des précautions particulières sont
nécessaires pour réduire le plus possible les pertes irréversibles d'espèces étudiées et prélever un échantillon
représentatif. Tout d'abord, si les matériaux de la sonde de prélèvement, des barboteurs et des tubes de
liaison sont mal choisis, ceux-ci pourraient réagir irréversiblement avec les espèces étudiées. Ensuite, si la
sonde contient des gouttelettes d'eau condensée avant les barboteurs, les espèces étudiées risquent de s'y
dissoudre et donc de ne pas être prises en compte dans le mesurage. En outre, si la fumée contient des
gouttelettes d'eau, il est possible que l'échantillon ne soit pas représentatif s'il n'est pas prélevé
isocinétiquement.
Les conditions d'écoulement au niveau du plan d'échantillonnage sont déterminées avant l'échantillonnage.
S'il y a des gouttelettes d'eau, alors un prélèvement isocinétique en plusieurs points de prélèvement est
nécessaire. L'homogénéité des profils spatiaux de la vitesse des effluents gazeux, de la température et de la
concentration en oxygène est examinée. Si une variabilité importante est observée pour l'un quelconque de
ces paramètres, mais qu'il n'y a aucune gouttelette d'eau, alors l'échantillonnage est réalisé en plusieurs
points de prélèvement, mais à un débit constant. Si ces paramètres sont homogènes, alors l'échantillonnage
est effectué en un seul point de prélèvement, à un débit constant.
Pour déterminer la teneur en fluorure gazeux des effluents gazeux, un échantillon représentatif quantifié de ce
gaz est acheminé vers une sonde de prélèvement chauffée et un filtre. Toute gouttelette d'eau susceptible de
contenir des composés de fluorure gazeux dissous est évaporée dans la sonde chauffée. Les particules
pouvant contenir des composés de fluorure à l’état solide sont retenues par filtration des particules à une
température contrôlée. Les composés de fluorure gazeux ou, plus précisément, les composés de fluorure
solubles dans l'eau qui traversent le filtre sont absorbés à l'aide d'une chaîne de prélèvement comprenant une
série de barboteurs qui contiennent une solution d'hydroxyde de sodium.
Les concentrations d'ions fluorures dissous dans les solutions recueillies sont mesurées selon la technique de
l'électrode sélective.
5 Réactifs
Pour mettre en œuvre cette méthode, il est nécessaire que les réactifs suivants soient de qualité analytique
reconnue. Si leur aspect a changé, il convient de les mettre au rebut.
5.1 Solution d'absorption, solution de NaOH à 0,1 mol/l.
5.2 Agent dessiccatif de l'échantillon de gaz, gel de silice moyen auto-indicateur.
5.3 Tampon commercial d'ajustement de force ionique totale (TISAB).
Chlorure de sodium
Acétate de sodium trihydraté
Citrate monohydraté trisodique
Acide acétique glacial
Eau déionisée ou distillée
NaOH à 5,0 mol/l
2 © ISO 2006 – Tous droits réservés
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ISO 15713:2006(F)
5.4 Solutions d'étalonnage
Eau déionisée ou distillée
Fluorure de sodium
6 Appareillage
6.1 Introduction
Une représentation schématique de l'équipement nécessaire à l'échantillonnage des fluorures gazeux est
donnée à la Figure 1. L'appareillage se compose de l'assemblage d'une sonde de prélèvement et d'un filtre
qui peuvent être chauffés si nécessaire, d'une chaîne de barboteurs contenant une solution d'hydroxyde de
sodium pour piéger les fluorures gazeux, d'un manomètre, d'une vanne de régulation de l'aspiration, d'une
pompe aspirante, d'un compteur à gaz et d'un système de mesurage du débit-volume du gaz prélevé. Un
thermomètre et un manomètre doivent être inclus dans la chaîne de prélèvement pour déterminer, si besoin,
la température et la pression relative du gaz dosé. Un baromètre doit être utilisé pour mesurer la pression
atmosphérique pendant l'essai afin que le volume de l'échantillon de gaz puisse être ramené aux conditions
normales de 273,15 K et 101,325 kPa.
6.2 Sonde
La sonde doit être une longueur de tube rigide et doit pouvoir supporter la température dans le conduit. Elle
doit être résistante aux attaques chimiques des différents polluants se trouvant dans le conduit. La sonde doit
plus particulièrement être résistante aux attaques de fluorure pour éviter les pertes d'échantillon. Les
®1)
matériaux adaptés au prélèvement de fluorure sont la silice ou les alliages de type Monel .
La sonde doit comprendre un système de chauffage permettant de maintenir le gaz à une température de
sortie d'au moins 423 K ou > 20 K ± 5 K au-dessus de la température du point de rosée, selon la température
la plus élevée.
Avant chaque prélèvement, les surfaces internes de la sonde de prélèvement doivent être minutieusement
nettoyées par rinçage à l'eau déionisée. Il sera d'abord nécessaire de laisser la sonde refroidir entre les
prélèvements. Le rinçage de la sonde doit être répété jusqu'à ce qu'il n'y ait plus aucune trace de poussières
dans l'eau de rinçage.
6.3 Filtre et logement du filtre
Un filtre doit être utilisé pour capter les poussières afin d'empêcher la dissolution de toute particule de fluorure
soluble. Les filtres peuvent être placés dans le conduit entre la buse et la sonde seulement s'il n'y a pas de
gouttelette d'eau ou à l'extérieur du conduit, avant le premier barboteur. Si un filtre est utilisé à l'extérieur du
conduit, il doit être chauffé à une température d'au moins 423 K ou > 20 K ± 5 K au-dessus de la température
du point de rosée, selon la température la plus élevée, pour éviter toute condensation. Si la quantité de
particules de fluorure dans l'échantillon est inférieure à 10 % du total, alors le filtre peut être omis.
Les matériaux utilisés pour les filtres et les porte-filtres doivent être résistants aux attaques de fluorure; les
frittés en verre, par exemple, piégeront le fluorure gazeux et ne peuvent donc pas être utilisés comme
support-filtre. Les support-filtres doivent être munis d'un joint étanche à l'air pour éviter les fuites provenant de
l'extérieur ou autour du filtre.
®
1) Les alliages de type Monel sont des exemples de produits appropriés disponibles sur le marché. Cette information
est donnée à l'intention des utilisateurs de la présente Norme internationale et ne signifie nullement que l'ISO approuve ou
recommande l'emploi exclusif des produits ainsi désignés.
© ISO 2006 – Tous droits réservés 3
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ISO 15713:2006(F)
Le filtre doit pouvoir supporter des expositions prolongées jusqu'à 40 K au-dessus de la température choisie
et avoir une efficacité de captation d'au moins 99,5 % pour des particules dont le diamètre est de 0,3 µm.
Avant utilisation et avant chaque prélèvement, le logement du filtre doit être minutieusement nettoyé à l'aide
d'eau distillée déionisée jusqu'à ce qu'il n'y ait plus de poussière sur les surfaces internes du porte-filtre.
6.4 Chaîne de prélèvement
Les barboteurs doivent être reliés à la sonde de prélèvement à l'aide de matériaux résistant au fluorure
®2)
d'hydrogène. Les matériaux qui conviennent sont le polypropylène, le polyéthylène ou le tubage Viton . La
chaîne de prélèvement se compose d'une série de quatre barboteurs au travers desquels les échantillons de
gaz passent et les fluorures sont retenus dans la solution. Les barboteurs peuvent être en quartz, en
polypropylène ou en polyéthylène. La taille qui convient est comprise entre 125 ml et 250 ml.
Les deux premiers barboteurs doivent contenir entre 50 ml et 100 ml d'une solution de NaOH à 0,1 mol/l de
qualité analytique.
Le troisième barboteur doit être laissé vide pour recueillir tout transfert par débordement de la solution
d'absorption.
Le quatrième barboteur doit être utilisé comme unité de séchage. Il n'est pas nécessaire que ses matériaux
de construction soient résistants au fluorure d'hydrogène. Il doit être rempli de gel de silice pour sécher
l'échantillon de gaz avant qu'il ne passe par l'unité d'aspiration, le compteur à gaz et le débitmètre. Avant
utilisation, tous les barboteurs doivent être rincés et nettoyés avec de l'eau distillée ou déionisée et un
écouvillon pour ballons.
Lors du prélèvement, les gaz doivent pénétrer dans le premier barboteur à sa base et barboter dans la
solution d'hydroxyde de sodium avant de pénétrer dans le deuxième barboteur, à sa base.
La géométrie des barboteurs et la quantité de solution d'absorption utilisée doivent être telles qu'une efficacité
d'absorption des fluorures gazeux d'au moins 95 % est atteinte au débit de prélèvement choisi et dans la
gamme de concentration examinée. Des preuves que ce critère est satisfait doivent être apportées en au
moins une occasion au débit maximal utilisé avec cet équipement ainsi conçu.
6.5 Unité d'aspiration
La pompe est utilisée pour acheminer l'échantillon à travers la chaîne de prélèvement. Il doit s'agir d'une
pompe étanche à l'air pouvant maintenir le débit de prélèvement choisi tout au long de la période de
prélèvement; elle doit être réglée à l'aide d'un régulateur de débit.
6.6 Thermomètre
Un thermomètre étanche à l'air doit être installé dans la ligne de prélèvement après l'unité de séchage et
avant le compteur à gaz. Le thermomètre doit pouvoir mesurer la température absolue à ± 1 % de la
température absolue.
6.7 Manomètre différentiel
Le manomètre différentiel doit être utilisé pour mesurer la différence de pression entre le gaz entrant dans le
compteur volumétrique et la pression atmosphérique. Il doit pouvoir mesurer une différence de pression à
± 1 % de la pression différentielle.
®
2) Le tubage Viton est un exemple de produit approprié disponible sur le marché. Cette information est donnée à
l'intention des utilisateurs de la présente Norme internationale et ne signifie nullement que l'ISO approuve ou recommande
l'emploi exclusif du produit ainsi désigné.
4 © ISO 2006 – Tous droits réservés
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ISO 15713:2006(F)
6.8 Compteur volumétrique
Le volume de l'échantillon de gaz doit être mesuré à l'aide d'un compteur à gaz étalonné. Le compteur à gaz
doit pouvoir mesurer le volume de gaz prélevé à ± 2 % du volume réel.
6.9 Débitmètre de gaz prélevé
Un débitmètre doit être utilisé pour garantir que le débit du gaz prélevé est compris dans les limites spécifiées
en 6.4, mais aussi pour effecteur les actions décrites en 7.5, 7.7 et 7.8. Cet instrument doit pouvoir mesurer le
débit à ± 10 % du flux.
6.10 Baromètre
Un baromètre doit être utilisé pour mesurer la pression atmosphérique locale, en kilopascals (kPa), à ± 1 %
de la pression absolue.
6.11 Plate-forme de travail
Une plate-forme de travail sécurisée doit être fournie sur le lieu de prélèvement de manière que les points de
prélèvement puissent être atteints en toute sécurité.
7 Échantillonnage
7.1 Lieu et points de prélèvement
Le lieu de prélèvement doit disposer d'un ou de plusieurs orifices d'accès adaptés, au travers desquels la
sonde de prélèvement peut être introduite pour pénétrer dans le conduit. L'orifice ou les orifices doivent
pouvoir être scellés lorsqu'ils ne sont pas utilisés. Le prélèvement peut être réalisé isocinétiquement (en cas
de présence de gouttelettes d'eau) ou non isocinétiquement en des points conformes aux exigences
appropriées de l'ISO 9096. Un prélèvement multipoints à un débit constant doit être effectué conformément
aux exigences appropriées de l'ISO 9096. L'échantillonnage sera normalement effectué sur au moins deux
diamètres du conduit et plusieurs points de prélèvement sur chaque ligne.
Lorsque c'est impossible, en raison de contraintes dues à la conception du conduit ou pour des raisons de
sécurité, le plan d'échantillonnage doit se situer sur une longueur droite du conduit, de préférence verticale,
ayant une forme et une aire de section constantes. Il doit être situé aussi loin que possible en aval de tout
obstacle susceptible de créer une zone de perturbation et de provoquer une modification de l'écoulement
(perturbations causées, par exemple, par un coude, un ventilateur ou un registre).
L'emplacement auquel un échantillon de gaz représentatif doit être prélevé est une partie importante du mode
opératoire d'échantillonnage. Un échantillonnage représentatif exige de prélever le gaz à partir d'un flux
homogène dans le conduit. Pour y parvenir, la vitesse, la température et la concentration en oxygène doivent
être d'abord déterminées en des points de prélèvement représentatifs du plan d'échantillonnage choisi.
L'objectif de ce mode opératoire est de confirmer que le profil de vitesse est conforme à l'exigence de
l'ISO 9096. La température et l'oxygène ne doivent pas varier le long du conduit de plus de 5 % de la valeur
moyenne pour éviter une stratification susceptible d'avoir une incidence sur la concentration mesurée. Si
aucune stratification n'est détectée, alors un point de prélèvement représentatif doit être choisi.
7.2 Durée de prélèvement minimale et volume minimal de l'échantillon
La période de prélèvement minimale et le nombre d'échantillons prélevés dépendront de la nature du
processus qui est à l'origine des émissions. La durée de prélèvement doit être d'au moins 30 min. Si les
émissions d'un processus cyclique doivent être mesurées, alors la période de prélèvement totale doit couvrir
au moins un cycle de fonctionnement du processus.
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ISO 15713:2006(F)
Le temps de prélèvement minimal nécessite aussi de tenir compte de la limite de détection de l'échantillon et
de la méthode analytique. Si le processus fonctionne dans des conditions de régime permanent, le temps de
prélèvement et le volume minimaux peuvent être calculés avant de procéder à l'échantillonnage, en utilisant la
concentration attendue du gaz émis ou un dixième de la valeur limite d'émission le cas échéant, ainsi que les
limites de détection de la chaîne de prélèvement indiquées en 10.1. Si un échantillonnage multipoints est
utilisé, le temps de prélèvement minimal en un point ne doit pas être inférieur à 3 min.
7.3 Nombre et lieu des points de prélèvement
Un lieu de prélèvement représentatif approprié doit être choisi. Le nombre et l'emplacement des points de
prélèvement sur le plan d'échantillonnage doivent être conformes à l'ISO 9096, sauf lorsque cela n'est pas
faisable.
Le prélèvement en un seul point doit être acceptable uniquement si la vitesse des effluents gazeux, la
température et la concentration en oxygène satisfont aux exigences indiquées en 7.1.
Si le prélèvement à partir de plusieurs points est requis, alors le temps de prélèvement choisi doit être
identique pour chaque point de prélèvement.
7.4 Autres mesurages à effectuer avant l'échantillonnage
7.4.1 Flux volumétrique dans le conduit au niveau du plan d'échantillonnage
Le mesurage du flux volumétrique dans le conduit au niveau du plan d'échantillonage sera nécessaire si les
résultats doivent être exprimés en termes de masse de polluant émis par unité de temps. Les mesurages
doivent être effectués conformément à l'ISO 10780.
7.4.2 Teneur en humidité du gaz
Le mesurage de la teneur en humidité du gaz sera nécessaire si les résultats doivent être exprimés en termes
de concentration en fluorure sur une base humide ou si le prélèvement doit être effectué isocinétiquement.
7.4.3 Teneur en oxygène du gaz
Si l'échantillonnage doit être effectué sur des émissions provenant d'un processus de combustion et si les
résultats doivent être rapportés après correction à une concentration en oxygène particulière, le mesurage de
la concentration en oxygène des effluents gazeux sera nécessaire lors de la période de prélèvement.
7.5 Assemblage de l'équipement de prélèvement
Le prélèvement est réalisé à l'aide de l'équipement assemblé représenté à la Figure 1.
NOTE Le filtre peut être placé dans le conduit ou à l'extérieur du conduit, avant le premier barboteur (voir 6.3).
Préchauffer toutes les pièces de la chaîne de prélèvement qui le nécessitent et insérer la sonde dans le
conduit, de manière que l'embout soit placé au niveau du premier point de prélèvement. Éviter tout contact
entre la sonde et les dépôts dans le conduit ou l'orifice de prélèvement. Sceller l'ouverture de l'orifice d'accès
pour réduire au minimum les entrées d'air.
7.6 Prélèvement
Si le prélèvement doit être réalisé isocinétiquement, cela doit être conformément aux exigences appropriées
de l'ISO 9096.
Si le prélèvement doit être réalisé en des points de prélèvement multiples, alors cela doit être conformément
aux exigences appropriées de l'ISO 9096.
6 © ISO 2006 – Tous droits réservés
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ISO 15713:2006(F)
Sinon, noter l'heure ainsi que l'indication du compteur à gaz courant, puis démarrer la pompe. Régler le débit
d'échantillonnage au niveau désiré à l'aide de la vanne de régulation de l'aspiration et du débitmètre. La
vitesse d'échantillonnage doit être suffisante pour permettre un barbotage vigoureux dans les deux premiers
barboteurs de la chaîne de prélèvement, mais pas trop vigoureux pour faire passer la solution dans le
troisième barboteur vide. Un débit de prélèvement constant doit être maintenu en chaque point (à ± 10 % du
débit choisi). Il convient de consigner périodiquement la température et la pression. Si plus d'un point de
prélèvement est utilisé sur une ligne d'échantillonnage, déplacer la sonde de prélèvement directement au
point suivant dès lors que la période de prélèvement en un point est achevée – ne pas arrêter la pompe. De
cette manière, achever les opérations de prélèvement en tous points d'une ligne. Si une autre ligne doit être
utilisée, la vanne de régulation de l'aspiration doit être fermée à la fin du prélèvement sur la première ligne et
la pompe arrêtée. Il convient de lire le compteur à gaz et de procéder aux opérations de prélèvement sur la
deuxième ligne comme pour la première.
Au terme de la période de prélèvement finale, la vanne de régulation de l'aspiration doit être fermée et la
pompe arrêtée. La valeur indiquée sur le compteur à gaz doit être relevée. Il convient alors de procéder à un
essai d'étanchéité de l'équipement.
NOTE Un débit de prélèvement compris entre 2 l/min et 6 l/min peut être suffisant pour permettre un barbotage
vigoureux.
Légende
1 sonde chauffée
2 filtre et logement
3 barboteurs de NaOH à 0,1 mol/l
4 collecteur
5 tube à dessécher ou gel de silice dreschel
6 pompe
7 thermomètre et manomètre
8 compteur à gaz
9 rotamètre
Figure 1 — Représentation schématique d'une chaîne de prélèvement
© ISO 2006 – Tous droits réservés 7
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ISO 15713:2006(F)
7.7 Mode opératoire du contrôle d'étanchéité
Un contrôle d'étanchéité avant essai est requis avant et après tout prélèvement et également si l'un
quelconque des composants de la chaîne de prélèvement est remplacé au cours d'un essai. Le débit de fuite
ne doit pas dépasser 2 % du débit nominal de prélèvement.
7.8 Contrôle d'étanchéité au cours du prélèvement
Si, au cours du prélèvement, il devient nécessaire de changer un composant (par exemple un filtre ou un
barboteur), un contrôle d'étanchéité doit être effectué immédiatement avant de procéder au changement. Le
contrôle d'étanchéité doit être effectué comme le contrôle d'étanchéité initial, sauf s'il doit être réalisé à un
vide égal ou supérieur à la valeur maximale enregistrée jusqu'à présent au cours de l'essai. Si le taux de fuite
déterminé n'est pas supérieur à 2 % de la vitesse de prélèvement moyenne, alors les résultats sont
acceptables. Si un taux de fuite plus important est mesuré, l'échantillon est vide.
7.9 Contrôle d'étanchéité après l'essai
Un contrôle d'étanchéité est obligatoire à l'issue de chaque échantillonnage. Le contrôle d'étanchéité doit être
effectué comme le contrôle d'étanchéité initial, sauf s
...
SLOVENSKI STANDARD
oSIST ISO 15713:2008
01-december-2008
(PLVLMHQHSUHPLþQLKYLURY9]RUþHQMHLQGRORþHYDQMHSOLQDVWHJDIOXRULGD
Stationary source emissions - Sampling and determination of gaseous fluoride content
Émissions de sources fixes - Échantillonnage et détermination de la teneur en fluorure
gazeux
Ta slovenski standard je istoveten z: ISO 15713:2006
ICS:
13.040.40 (PLVLMHQHSUHPLþQLKYLURY Stationary source emissions
oSIST ISO 15713:2008 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST ISO 15713:2008
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oSIST ISO 15713:2008
INTERNATIONAL ISO
STANDARD 15713
First edition
2006-06-01
Stationary source emissions — Sampling
and determination of gaseous fluoride
content
Émissions de sources fixes — Échantillonnage et détermination de la
teneur en fluorure gazeux
Reference number
ISO 15713:2006(E)
©
ISO 2006
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oSIST ISO 15713:2008
ISO 15713:2006(E)
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Published in Switzerland
ii © ISO 2006 – All rights reserved
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oSIST ISO 15713:2008
ISO 15713:2006(E)
Contents Page
Foreword. iv
Introduction . iv
1 Scope .1
2 Normative references .1
3 Terms and definitions .1
4 Principle.2
5 Reagents.2
6 Apparatus .3
7 Sampling.5
8 Analytical procedure by ion selective electrode .9
9 Expression of results .11
10 Performance characteristics .13
11 Test report .13
© ISO 2006 – All rights reserved iii
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oSIST ISO 15713:2008
ISO 15713:2006(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 15713 was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1, Stationary
source emissions.
iv © ISO 2006 – All rights reserved
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oSIST ISO 15713:2008
ISO 15713:2006(E)
Introduction
This International Standard describes a method for the measurement of the concentration of gaseous fluoride
compounds in flue gas passing through ducts or chimneys.
The effects of fluoride containing species are of concern as irritants to humans when inhaled at high
concentration and because of the potential for adverse effects on vegetation.
For the purposes of this International Standard, the fluoride measured is quoted as hydrogen fluoride. The aim
of the method is to measure hydrogen fluoride, but, in practice, the parameter assessed is operationally
defined. The fluoride measured is from those compounds that pass through a filter and dissolve in dilute
sodium hydroxide and which produce fluoride ions which remain present in solution when analysed.
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oSIST ISO 15713:2008
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oSIST ISO 15713:2008
INTERNATIONAL STANDARD ISO 15713:2006(E)
Stationary source emissions — Sampling and determination of
gaseous fluoride content
1 Scope
This International Standard is applicable to the measurement of the gaseous fluorides that are entrained in
gases carried in stacks or ducts. The gaseous fluoride content is expressed as a mass of hydrogen fluoride in
the stack gas.
This International Standard is applicable to all stacks emitting gases with fluoride concentrations of below
3
200 mg/m . It can be used for higher concentrations, but then the absorption efficiency of the bubblers should
be checked before the results can be regarded as valid. The detection limit of the method is estimated as
−3 3
0,1 mg m , based on a sample volume of 0,1 m . All compounds that are volatile at the filtration temperature
and produce soluble fluoride compounds upon reaction with water are measured by this method. The method
does not measure fluorocarbons. The concentration of fluoride in the adsorbent solution is then measured
using an ion selective electrode. The amount of fluoride measured is then expressed as hydrogen fluoride by
convention, though this may not reflect the chemical nature of the compounds, which are measured.
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 9096:2003, Stationary source emissions — Manual determination of mass concentration of particulate
matter
ISO 10780, Stationary source emissions — Measurement of velocity and volume flowrate of gas streams in
ducts
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
isokinetic sampling
sampling at a flowrate such that the velocity and direction of the gas entering the sampling nozzle is the same
as that of the gas in the duct at the sampling point
[ISO 9096:2003]
3.2
sampling point
specific position on the sampling section at which a sample is extracted
NOTE Sampling points are spread out over the sampling section in order to be representative of subsections of equal
areas.
© ISO 2006 – All rights reserved 1
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oSIST ISO 15713:2008
ISO 15713:2006(E)
3.3
STP
standard conditions for temperature, 273,15 K, and pressure, 101,325 kPa
4 Principle
As a result of the high reactivity and solubility of hydrogen fluoride, particular precautions are required to
minimize irreversible loss of the species of interest and to take a representative sample. Firstly, if incorrect
materials are selected for the sampling probe, impingers and connecting tubing they could react irreversibly
with the species of interest. Secondly, if condensed liquid droplets are present in the probe before the
impingers the species of interest may dissolve in them and so not be included in the measurement. Further,
where droplets are present in the flue, if the sample is not taken isokinetically, then it may not be
representative.
The flow conditions at a sampling plane are determined before sampling. If there are droplets present, then
isokinetic sampling at a number of sampling points is necessary. The homogeneity of the spatial profiles of the
flue gas velocity, temperature and oxygen concentration is investigated. If there is significant variability in any
of these parameters, but no droplets, then sampling is carried out at a number of sampling points but at a
constant flow rate. If these parameters exhibit homogeneity, then sampling is carried out at a single point at a
constant flow rate.
To determine the gaseous fluoride content of the flue gas, a representative metered sample of that gas is
drawn through a heated sampling probe and filter. Any droplets, which may contain dissolved gaseous fluoride
compounds, are evaporated in the heated probe. Particulate bound fluoride species that may be present as
solid materials are removed by filtration of particulates at a controlled temperature. Gaseous fluoride
compounds or more precisely those water-soluble fluoride compounds that pass through the filter are
absorbed using a sampling train made up of a series of impingers containing a sodium hydroxide solution.
The concentrations of dissolved fluoride ions in the collected solutions are measured using the ion selective
electrode technique.
5 Reagents
To carry out the method, the following reagents are required to be of a recognized analytical grade. If they
have changed visibly, they should be discarded.
5.1 Absorber solution, 0,1 mol/l NaOH solution.
5.2 Sample gas drying agent, self-indicating coarse grade silica gel.
5.3 Total ionic strength adjustment buffer (TISAB).
Sodium chloride
Sodium acetate trihydrate
Trisodium citrate monohydrate
Glacial acetic acid
Deionized or distilled water
5,0 mol/l NaOH
2 © ISO 2006 – All rights reserved
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oSIST ISO 15713:2008
ISO 15713:2006(E)
5.4 Calibration solutions.
Deionized or distilled water
Sodium fluoride
6 Apparatus
6.1 Introduction
A schematic diagram of the equipment for the sampling of gaseous fluorides is given in Figure 1. The
apparatus consists of a sampling probe and filter assembly that may be heated if required, an impinger train
containing sodium hydroxide solution to capture gaseous fluorides, a pressure gauge, a suction control valve,
a suction pump, a gas meter, and a sample gas volume flow rate measurement system. A thermometer and
manometer shall be included in the sample train to allow the temperature and relative pressure of the metered
gas to be determined. A barometer shall be used to measure atmospheric pressure during the test in order
that the volume of the gas sampled can be normalized to standard conditions of 273,15 K and 101,325 kPa.
6.2 Probe
The probe shall be a length of rigid tubing and shall be capable of withstanding the temperature within the
duct. It shall be resistant to chemical attack from the various pollutants in the duct. In particular, the probe
shall be resistant to fluoride attack to avoid sample loss. Suitable materials for fluoride sampling are silica or
® 1)
Monel type alloys .
The probe shall have a heating system capable of maintaining a gas temperature at its exit of at least 423 K or
> 20 K ± 5 K above the dew point temperature, whichever is the higher.
The internal surfaces of the sample probe shall be cleaned thoroughly before each sample run by rinsing it
with deionized water. Between samples, it will first be necessary to allow the probe to cool. The probe rinse
shall be repeated until the rinse water shows no evidence of particulate matter.
6.3 Filter and filter housing
A filter shall be used to capture particulate material to prevent dissolution of any soluble particulate fluoride.
Filters can be placed in the duct between the nozzle and the probe only if there are no droplets present, or out
of the duct before the first impinger. If a filter is used outside the duct, it shall be heated to a temperature of at
least 423 K or > 20 K ± 5 K above the dew point temperature, whichever is the higher, to avoid condensation.
If the amount of particulate fluoride within the sample is below 10 % of the total, then the filter can be omitted.
Filters and filter holders shall be made of material resistant to attack by fluorides; for example, glass frits will
remove gaseous fluoride and therefore cannot be used as filter supports. Filter holders shall have an airtight
seal against leakage from outside or around the filter.
The filter shall be capable of withstanding prolonged exposures up to 40 K above the temperature setting and
have at least 99,5 % collection efficiency for 0,3 µm diameter particles.
The filter housing shall be cleaned thoroughly prior to use and before each sample run using deionized
distilled water until no particulate matter is present on the inner surfaces of the filter holder.
®
1) Monel type alloys is an example of a suitable product(s) available commercially. This information is given for the
convenience of users of this International Standard and does not constitute an endorsement by ISO of this product.
© ISO 2006 – All rights reserved 3
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oSIST ISO 15713:2008
ISO 15713:2006(E)
6.4 Sampling train
The impingers shall be connected to the sampling probe using HF resistant materials. Suitable materials are
® 2)
polypropylene, polyethylene or Viton tubing . The sampling train consists of a series of four impingers
through which the sample gases are passed and the fluorides are removed into solution. The impingers can
be made of quartz, polypropylene or polyethylene. Convenient sizes for impingers are 125 ml to 250 ml.
The first two impingers shall contain between 50 ml and 100 ml of 0,1 mol/l NaOH solution of analytical grade.
The third impinger shall be left empty to catch any carryover of the absorption solution.
The fourth impinger shall be used a drying unit. Its materials of construction need not be resistant to HF. It
shall be filled with silica gel to dry the sample gas prior to the suction unit, gas meter and volume flow meter.
Prior to use, the impingers shall all be rinsed and cleaned with distilled or deionized water and a bottlebrush.
During sampling, the gases shall enter the first impinger at its base and bubble up through the sodium
hydroxide solution before entering the second impinger at its base.
The geometry of the impingers and quantity of absorbing solution employed shall be such that a gaseous
fluoride absorbance efficiency of not less than 95 % is achieved at the chosen sampling flow rate and in the
concentration range examined. Evidence that this criteria is met shall be demonstrated on at least one
occasion at the maximum flow rate used with that design of equipment.
6.5 Suction unit
The pump is used to draw the sample through the sampling train. It shall be an airtight pump capable of
maintaining the selected sampling flow rate throughout the sampling period and shall be adjusted using a flow
regulator.
6.6 Thermometer
An airtight thermometer shall be fitted into the sample line after the drying unit and before the gas meter. The
thermometer shall be capable of measuring absolute temperature to within 1 % of the absolute temperature.
6.7 Differential pressure gauge
The differential pressure gauge shall be used to measure the difference in pressure between the gas entering
the volume meter and atmospheric pressure. It shall be capable of measuring pressure difference to within 1%
of the differential pressure.
6.8 Gas volume meter
The volume of the dried sample gas shall be measured using a calibrated gas meter. The gas meter shall be
capable of measuring the sampled gas volume to within 2 % of the actual volume.
6.9 Sample gas flow rate meter
A flow rate meter shall be used to ensure that the sample flow rate stays within the limits specified in section
6.4 and to perform the actions described in 7.5, 7.7 and 7.8. This meter shall be capable of measuring the flow
rate to within ± 10 % of the flow.
6.10 Barometer
A barometer shall be used to measure the local atmospheric pressure in kilopascals (kPa) to within 1 % of the
absolute pressure.
®
2) Viton tubing is an example of a suitable product(s) available commercially. This information is given for the
convenience of users of this International Standard and does not constitute an endorsement by ISO of this product.
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6.11 Working platform
A safe working platform shall be provided at the sampling position so that all the sampling points can be
reached with safety.
7 Sampling
7.1 Sampling position and sampling points
The sampling position shall comprise of suitable access port(s) through which the sampling probe can be
passed into the duct. The port(s) shall be capable of being sealed when not in use. Sampling can be
performed either isokinetically (if droplets are present) or non-isokinetically at points according to the relevant
requirements of ISO 9096. Multipoint sampling at a constant flow rate shall be carried at according to the
relevant requirements of ISO 9096. Sampling will normally be carried out on at least two duct diameters and at
a number of sampling points on each line.
Where this is not possible, due to constraints of either duct design or safety considerations, the sampling
plane shall be situated in a length of straight duct, preferably vertical with a constant shape and constant
cross-sectional area. It shall be as far as practicable downstream from any obstruction that may cause a
disturbance or produce a change in the flow (for example, a bend, a fan or a damper).
The position at which a representative sample of the gas is to be taken is an important part of the sampling
procedure. Representative sampling requires the gas to be taken from a homogenous flow in the duct. To
achieve this, the velocity, temperature, and the oxygen concentration, shall first be determined at
representative sampling points across the chosen sampling plane. The object of this procedure is to confirm
that the velocity profile conforms to the requirement of ISO 9096. The temperature and oxygen shall not vary
across the duct by more than 5 % from the mean value to avoid stratification affecting the measured
concentration. If no stratification is detected, then a representative location shall be chosen for sampling.
7.2 Minimum sampling duration and minimum sample volume
The minimum sampling period and number of samples taken will depend on the nature of the process that is
producing the emissions. The sampling duration shall be at least 30 min. If emissions from a cyclical process
are to be measured, the total sampling period shall cover at least one cycle of the process operation.
The minimum sampling time also needs to take into account the detection limit of the sampling and analytical
method. If the process is operating under steady state conditions, the minimum sampling time and volume can
be calculated prior to sampling, by using the expected emitted gas concentration or a tenth of the emission
limit value if appropriate and the sample train detection limits given in 10.1. If multiple point sampling is
employed, the minimum sampling time at any one point shall not be less than 3 min.
7.3 Number and location of sampling points
An appropriate representative location shall be chosen for sampling. The number and location of the sampling
points on the sampling plane shall conform to ISO 9096, unless this is not practicable.
Sampling at a single point shall only be acceptable if the flue gas velocity, temperature, and oxygen
concentrations meet the requirements stated in 7.1.
If sampling from a number of points is required, then the sampling time chosen shall be the same at each
sample point.
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7.4 Other measurements to be made prior to sampling
7.4.1 Volumetric gas flow through duct at the sampling plane
The measurement of the volumetric gas flow through the duct at the sampling plane will be necessary if the
results are to be reported in terms of mass of pollutant emitted per unit time. The measurements shall be
carried out in accordance with ISO 10780.
7.4.2 Moisture content of gas
The measurement of the moisture content of the gas will be necessary if the results are to be reported as a
fluoride concentration on a wet basis or if the sampling is to be carried out isokinetically.
7.4.3 Oxygen content of gas
If sampling is to be carried out of emissions from a combustion plant and the results are to be reported after
correction to a particular oxygen concentration, measurement of the flue gas oxygen concentration will be
necessary during the sampling period.
7.5 Assembly of sampling apparatus
Sampling is carried out with the apparatus assembled as illustrated in Figure 1.
NOTE The filter can be positioned in the duct or out of the duct before the first impinger (see 6.3).
Preheat all relevant parts of the sampling train and insert the probe into the duct, so that the sampling tip is
positioned at the first sampling point. Avoid contact between the probe and any deposits in the duct or
sampling port. Seal the opening of the access port to minimize air in-leakage.
7.6 Sampling
If the sampling is to be carried out isokinetically, this shall be done according to the relevant requirements of
ISO 9096.
If sampling is to be carried out at multiple sampling positions, this shall be done according to the relevant
requirements of ISO 9096.
Otherwise, record the time and the current gas meter reading, then start the pump. Set the sampling flow rate
to the desired level using the suction control valve and the flow rate meter. The sampling rate shall be
sufficient to allow vigorous bubbling within the first two impingers of the sampling train but not so vigorous that
the solution is carried over into the third empty impinger. A constant sampling flow rate shall be maintained at
each point (to within ± 10 % of the chosen rate). Meter temperature and pressure should be recorded
periodically. If more than one sampling point is employed on a sampling line, then move the sampling probe
directly to the next point once the sampling period at that point is complete — do not switch off the pump. In
this way, complete the sampling operations at all points on one line. If another line is to be employed, the
suction control valve shall be closed at the end of sampling on the first line and the sampling pump switched
off. The gas meter should be read and sampling operations carried out on the second line as before.
At the end of the final sampling period, the suction control valve shall be closed and the sampling pump
switched off. The gas meter shall be read. A leak test of the equipment should then be carried out.
NOTE A sample rate of between 2 l/min and 6 l/min may be sufficient to allow vigorous bubbling.
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Key
1 heated probe
2 filter and housing
3 0,1 molar NaOH impingers
4 catchpot
5 drying tube or silica gel dreschel
6 pump
7 temperature and pressure gauges
8 gas meter
9 rotameter
Figure 1 — Schematic diagram of a sampling train
7.7 Leak-check procedure
A pre-test leak-check is required before and after all sampling and also if any of the sampling train
components are replaced during a test. The leak rate shall not exceed 2 % of the nominal sample gas flow
rate to be used.
7.8 Leak-checks during sample run
If, during the sampling run, a component (e.g. filter assembly or impinger) change becomes necessary, a leak
check shall be conducted immediately before the change is made. The leak-check shall be carried out as the
initial leak check, except that it shall be done at a vacuum equal to or greater to the maximum value recorded
up to that point in the test. If the leakage rate is found to be no greater than 2 % of the average sampling rate,
the results are acceptable. If a higher leakage rate is measured, the sample is void.
7.9 Post-test leak-check
A leak-check is mandatory at the conclusion of each sampling run. The leak-check shall be carried out as the
initial leak check, except that it shall be conducted at a vacuum equal to or greater than the maximum value
reached during the sampling run. If the leakage rate is found to be no greater than 2 % of the average
sampling rate, the results are acceptable. If a higher leakage rate is measured, the sample is void.
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7.10 Quality assurance
Prior to sampling make a note of the time and the current gas meter reading. During sampling, the flow rate of
the sample gas shall be noted periodically, together with the temperature and pressure at the gas meter to
allow the calculation of the average temperature and pressure during the sampling period.
During sampling, operatives shall periodically check and correct the following:
⎯ that the flow rate has not drifted by more than ± 10 % of the chosen flow rate;
⎯ that the silica gel has not been exhausted. If the colour of the silica gel indicates that it is nearly
exhausted, then the pump shall be switched off and the sampler withdrawn from the duct to be leak
tested while a new bottle of silica gel is fitted into the system.
If any of the components are replaced, then the leak test shall be performed again.
The leak rate measured during any leak test shall not be greater than 4 % of the nominal flow rate. If the leak
rate is greater than this, then the concentration measured will be an underestimate of the true value. If the
measured concentrations are above the appropriate limit value then the result can be used as a lower
estimate of the true concentration in the flue gas. However, in other circumstances, the result is invalid.
7.11 Sample recovery
Analysis of the particulate bound fluorides on the filter is not required by this International Standard and so it
may be discarded.
The fluorides contained in the impingers shall be carefully recovered as soon as possible.
Withdraw the probe from the stack and allow it to cool so that it can be handled.
Wipe off all external particulate matter near the tip of the probe.
If a filter following the probe was used, then disconnect the probe from the sampling train and check to see if
there is any condensation present within the probe. If there is evidence of condensation, the test shall be
rejected. The contents of the three impingers shall be carefully poured into a sample container, each impinger
shall be rinsed with approximately 20 ml of deionized distilled water, and these washings shall be added to a
sample container. Repeat the process for each impinger. If the adsorption efficiency of the sampler is being
determined, the impinger solutions should be kept
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