SIST EN 1911:2011

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Emissionen aus stationären Quellen - Bestimmung der Massenkonzentration von gasförmigen Chloriden, angegeben als HCl - StandardreferenzverfahrenEmissions de sources fixes - Détermination de la concentration massique en chlorures gazeux, exprimée en HCl - Méthode de référence normaliséeStationary source emissions - Determination of mass concentration of gaseous chlorides expressed as HCl - Standard reference method13.040.40Stationary source emissionsICS:Ta slovenski standard je istoveten z:EN 1911:2010SIST EN 1911:2011en,fr,de01-februar-2011SIST EN 1911:2011SLOVENSKI
STANDARDSIST EN 1911-3:1999SIST EN 1911-2:1999SIST EN 1911-1:19991DGRPHãþD

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 1911
August 2010 ICS 13.040.40 Supersedes EN 1911-1:1998, EN 1911-2:1998, EN 1911-3:1998English Version
Stationary source emissions - Determination of mass concentration of gaseous chlorides expressed as HCl - Standard reference method
Emissions de sources fixes - Détermination de la concentration massique en chlorures gazeux, exprimée en HCl - Méthode de référence normalisée
Emissionen aus stationären Quellen - Bestimmung der Massenkonzentration von gasförmigen Chloriden, angegeben als HCl - Standardreferenzverfahren This European Standard was approved by CEN on 26 June 2010.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions.
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Examples of absorbers . 32Annex B (informative)
Comparison between mercuric-thiocyanate spectrophotometry and ion exchange chromatography method (methods B and C) . 34Annex C (informative)
Example of assessment of compliance of the reference method for chlorides . 35C.1General . 35C.2Process of uncertainty estimation . 35C.3Specific conditions in the field . 36C.4Performance characteristics of the method . 37C.5Calculation of standard uncertainty of concentration measured. 38C.6Calculation of the overall (or expanded) uncertainty . 41C.7Uncertainty associated to the mass concentration of gaseous chlorides at O2 reference concentration . 41Annex D (informative)
Performance characteristics of the whole measurement method . 43D.1Analytical detection limit of the method . 43D.2Repeatability and reproducibility of the method in the field . 43Annex E (informative)
Significant technical changes . 45Bibliography . 46 SIST EN 1911:2011

NOTE 2 The required uncertainty results from the capacity of the method tested in the field (Annex D) and in the laboratory (see performance characteristics in Tables 1 and 2 and Annex C). 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. EN 13284-1:2001, Stationary source emissions — Determination of low range mass concentration of dust — Part 1: Manual gravimetric method ENV 13005, Guide to the expression of uncertainly in measurement EN 15259:2007, Air quality — Measurement of stationary source emissions — Requirements for measurement sections and sites and for the measurement objective, plan and report EN ISO 3696:1995, Water for analytical laboratory use — Specification and test methods (ISO 3696:1987) EN ISO 10304-1, Water quality — Determination of dissolved anions by liquid chromatography of ions — Part 1: Determination of bromide, chloride, fluoride, nitrate, nitrite, phosphate and sulfate (ISO 10304-1:2007) EN ISO 14956, Air quality — Evaluation of the suitability of a measurement procedure by comparison with a required measurement uncertainty (ISO 14956:2002) 3 Terms, definitions and abbreviations 3.1 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1.1 absorber device in which gaseous chloride is absorbed into an absorption solution 3.1.2 chemical blank chloride ion content of an unexposed sample of the absorption solution, plus reagents that are added to the solution before analysis if necessary SIST EN 1911:2011

DL concentration value of the measurand below which there is at least 95 % level of confidence that the measured value corresponds to a sample free of that measurand 3.1.4 field blank value determined by a specific procedure used to ensure that no significant contamination has occurred during all steps of the measurement and to check that the operator can achieve a quantification level adapted to the task 3.1.5 isokinetic sampling sampling at a rate 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 [EN 13284-1:2001] 3.1.6 measurand particular quantity subject to measurement [ISO/IEC Guide 99:2007, 2.6] 3.1.7 measurement series several successive measurements carried out on the same sampling plane and at the same process operating conditions [EN 13284-1:2001] 3.1.8 performance characteristic one of the quantities (described by values, tolerances, range, etc.) assigned to equipment in order to define its performance 3.1.9 analytical repeatability closeness of the agreement between the results of successive measurements of the same measurand carried out under the same conditions of measurement NOTE 1 Analytical repeatability conditions include:  the same measurement procedure;  the same laboratory;  the same sampling equipment, used under the same conditions and at the same location;  repetition over a short period of time. NOTE 2 Analytical repeatability may be expressed quantitatively in terms of the dispersion characteristics of the results.
[ISO/IEC Guide 99:2007, 3.6] NOTE 3 In this European Standard the analytical repeatability is expressed as a value with a level of confidence of 95 %. SIST EN 1911:2011

SRM measurement method recognised by experts and taken as a reference by convention, which gives, or is presumed to give, the accepted reference value of the concentration of the measurand to be measured 3.1.16 uncertainty parameter associated with the result of a measurement, that characterises the dispersion of the values that could reasonably be attributed to the measurand 3.1.17 standard uncertainty
u uncertainty of the result of a measurement expressed as a standard deviation
3.1.18 expanded uncertainty
U quantity defining a level of confidence about the result of a measurement that may be expected to encompass a specific fraction of the distribution of values that could reasonably be attributed to a measurand NOTE 1 ukU.= NOTE 2 In this European Standard, the expanded uncertainty is calculated with a coverage factor of k = 2, and with a level of confidence of 95 %. 3.1.19 combined uncertainty
uc standard uncertainty uattached to the measurement result calculated by combination of several standard uncertainties according to GUM
NOTE ∑==Niicuu12 3.1.20 overall uncertainty
cU expanded combined standard uncertainty attached to the measurement result calculated according to GUM NOTE ccukU×= 3.2 Abbreviations AgC
concentration of silver nitrate solution, in moles per litre (mol/l) rCI repeatability confidence interval RCI reproducibility confidence interval SIST EN 1911:2011

A known volume of flue gas is extracted representatively from a duct or a chimney during a certain period of time at a controlled flow rate with a heated probe. A heated filter removes the dust in the sampled volume, thereafter the gas stream containing gaseous chlorides is passed through a series of absorbers containing an absorption solution (chloride-free water). All compounds which are volatile at the temperature of filtration and produce chloride ions upon dissolution during sampling are measured by this method, which gives therefore the volatile inorganic chlorides content of the waste gas. The results shall be expressed as HCI. After sampling the solutions are analysed by one of the following methods:  silver titration: potentiometric method (Method A);  mercuric-thiocyanate spectrophotometry (Method B);  ion-exchange chromatography (Method C). 5 Sampling 5.1 Sampling strategy 5.1.1 General The test programme shall be established following the advice and requirements described in EN 15259:2007 (5.4, Clauses 6, 7 and 8). a) Quantification of several compounds simultaneously, if relevant. NOTE 1 Compounds such as gaseous chlorides, HF, SO2, NH3 and water vapour, can be sampled simultaneously in parallel side stream lines. NOTE 2 When performing isokinetic sampling the presence of water droplets means water vapour cannot be measured simultaneously in the same equipment. SIST EN 1911:2011

Key 1 heated sampling probe
5 cartridge with desiccant (optional) 2 heated particle filter (alternatives)
6 pump 3 absorber(s)
7 flow meter behind the filter (e.g. diaphragm) or before the gas meter 4 guard bottle (optional)
8 gas meter Figure 1 — Example of non-isokinetic sampling equipment SIST EN 1911:2011

Key 1 heated sampling probe
5 cartridge with desiccant (optional) 2 heated particle filter (alternatives)
6 pump 3 absorber(s)
7 flow meter behind the filter (e.g. diaphragm) or before the gas meter 4 guard bottle (optional)
8 gas meter Figure 2 — Example of isokinetic sampling equipment with a side stream For practical reasons it is difficult to adjust the secondary line volume flow rate quickly at each sampling point. Therefore, in the cases where the concentration is homogeneous in the sampling section, the flow rate can be kept constant. However, if the concentrations across the sampling section are not homogeneous, then the laboratory shall decide, depending on the measuring quality objectives to be reached, to fulfil or not the requirement EN 15259 of a flow rate proportional to the local velocity at each sampling point. The respect of EN 15259 is much easier using an isokinetic sampling system without any side stream (see 5.1.3.2). 5.1.3.2 Isokinetic sampling without any side stream A sampling system without any secondary line (side stream) can be used provided that the absorption efficiency requirements in 5.2.1.2.2 are fulfilled. NOTE An advantage of an isokinetic sampling without a side stream is that a flow rate proportional to the local velocity at each sampling point can be maintained more easily when a non homogeneity is detected in the sampling section. SIST EN 1911:2011

Key 1 heated sampling probe
5 cartridge with desiccant (optional) 2 heated particle filter (alternatives)
6 pump 3 absorber(s)
7 flow meter behind the filter (e.g. diaphragm) or before the gas meter 4 guard bottle (optional)
8 gas meter Figure 3 — Example of isokinetic sampling equipment without any side stream 5.1.4 Losses of gaseous chlorides and side reactions during sampling Attention is drawn to the risks of losses of gaseous chlorides in the sampling system, due to its high reactivity and solubility. All the parts of the sampling system upstream of the absorber shall be made of inert materials, and shall be heated in order to avoid cold points, which can lead to large losses of gaseous chlorides. Any parts that are not heated shall be rinsed. Some kinds of waste gases (e.g. incinerator plants, etc.) may contain chemical species (e.g. calcium salts or hydroxide, ammonium salts or free ammonia, etc.) which can react with gaseous chlorides. 5.2 Sampling equipment 5.2.1 Isokinetic sampling equipment. The items described hereafter assume that a side stream is used. If it is not the case, the absorbers and other components described in 5.2.1.2.2 to 5.2.1.2.5 are used. NOTE An example of the whole isokinetic sampling equipment is shown in Figures 2 and 3. 5.2.1.1 Main line. 5.2.1.1.1 Probe. The heated probe and entry nozzle shall be designed in accordance with EN 13284-1. However, since these parts are often made of borosilicate glass, which is difficult to manufacture to close tolerances, requirements may be less stringent concerning the edge of the entry nozzle. The length of the probe shall be enough to preheat the gas before entering the filter. In order to access the representative measurement point(s) of the sampling plane, probes of different lengths and inner diameters may be used, but the residence time of the sample gas in the probe shall be minimised.
The probe may be marked before sampling in order to reach more easily the representative measurement point(s) in the measurement plane. 5.2.1.1.2 Filter housing. The filter housing is located just before the probe (in-stack filtration) or directly behind the probe (out-stack filtration). SIST EN 1911:2011

NOTE 1
The filter housing may be jointed with the probe thereby avoiding leaks. NOTE 2
A stop valve after the filter housing can be useful to prevent back flush of absorption solution into the probe or into the filter when sampling in flue gases under unfavourable conditions (e.g. high depression in the duct). NOTE 3 In special cases where the sample gas temperature is > 200 °C, the heating jacket around the sampling probe, filter housing and connector line may be switched off. However the temperature in the sampled gas just after the filter housing should not fall below 20 °C above the dew point temperature. 5.2.1.1.3 Particle filter. The efficiency of the filter material shall be better than 99,5 % on a test aerosol of 0,3 µm mean diameter (or 99,9 % on a test aerosol of 0,6 µm mean diameter), for the maximal actual volume flow rate of the filter, to avoid measurement errors due to fine particles of chloride salts which could be collected in the absorbers and analysed as gaseous chlorides. Filters with the most suitable properties for this purpose are plane filters: convenient borosilicate glass and quartz fibres filters of different diameters and certified efficiency are commercially available. Diameters of about 40 mm to 160 mm are generally convenient. Filters of different designs may be used, but the residence time of the sample gas shall be minimised. For plants with dust concentration less than 5 mg/m3, a simplified filtration technique can be used (e.g. quartz wool plugs in a heated housing). 5.2.1.1.4 Temperature controller. A temperature controller is required for the probe and filter housing. It shall be capable of controlling temperature with an uncertainty of 2,5 K or better (uncertainty of calibration). 5.2.1.1.5 Suction and volume flow meter. The unit for suction and metering the volume flow rate in the main line shall have an adjustable volume flow rate and flow meter, in order to comply with isokinetic criteria. Various kinds of devices may be used, for instance:  volume flow rate measurement on wet basis using an heated orifice plate followed or not by a compressed air ejector acting as suction device;  water vapour removing device (condenser, dryer, etc.), leak tight pump, volume and flow meter. If the flow meter is placed just after the filter, it shall be calibrated and data corrected (temperature, pressure, humidity) to fulfil the isokinetic criterion. If the flow meter is placed just before the volume meter, the volume flow rate in the secondary line shall be taken into account in order to calculate the total volume flow rate in the main line. 5.2.1.2 Secondary line (optional for Isokinetic sampling without any side stream). 5.2.1.2.1 Connection to the main line. A tee piece ensures the division of the sample between the secondary line which allows a gas volume flow rate that fulfils the collection efficiency criteria and the main line. SIST EN 1911:2011

The absorption is tested as follows:  Carry out sampling in normal conditions.
 Remove the absorbers from the sampling train and transfer the sample solution from last absorber into a separate sample bottle. If a trap is used behind the absorbers to collect any solution carry-over, its contents shall be combined with the sample of downstream bottle. Rinse each absorber with the absorption solution (5.2.4) thoroughly and particularly the fritted glass dividers, if they are used to recover the absorption solution trapped in it and add the rinsing solutions to the appropriate absorber sample. Rinse all the unheated parts of the sampling system between the filter and the absorber 1 and add the rinsing to the content of the first bottle(s).  Analyse samples of the first(s) absorber(s) and of the last absorber separately as described in Clause 6 to determine the chloride content, qs1 and qs2. Check that the content in the last absorber is less than required. 5.2.1.2.3 Sampling pump. Leak-free pump capable of sampling gas at a set flow rate. NOTE
A rotameter (optional) facilitates the adjustment of the nominal sampling flow rate.
5.2.1.2.4 Gas volume meter. SIST EN 1911:2011

When using a dry gas volume meter, a condenser and/or a gas drying system shall be used which can lead to a residual water vapour content of less than 10 g⋅m-3 (equivalent to a dew point of 10,5 °C or a volume content χ(H2O) = 1,25 %). NOTE 1 For example a glass cartridge or absorption bottle packed with silica gel (1 mm to 3 mm particle size), which has been previously dried at least at 110 °C for at least 2 h. When using a wet gas volume meter, a correction shall be applied for water vapour, to obtain a dry gas sampled volume. For "dry" gas meter: 3,101273,respTstdppTVV−××= (1) For "wet" gas meter: 3,101)(2732,OHppTVVspTstd−××= (2) where stdV is the volume under standard conditions and dry basis, in cubic metres (m³); pTV, is the volume under actual conditions of temperature and pressure, on dry basis with "dry" gas meter or wet basis with "wet" gas meter, in cubic metres (m³); T
is the actual temperature, in Kelvins (K); p
is the total pressure in kilopascals (kPa) (i.e. atmospheric pressure + static pressure) at the gas meter; )(2OHpSis the saturated vapour pressure at the temperature of the gas meter, in kilopascals (kPa); resp
is the residual vapour pressure, in kilopascals (kPa). NOTE 2 The relative pressure can be neglected if the gas volume meter is the last equipment of the sampling chain. 5.2.1.2.5 Optional additional apparatus.  A shut-off device for the secondary line that allows isolation of the sampling line may be used. If such a device is used, it shall be capable of being rinsed completely after each sampling operation.  An additional bottle may be located just before the main absorber; this arrangement prevents liquid being sucked back in the event of mishandling, but condensation often occurs in it. If such a device is used, it shall be rinsed completely after each sampling operation, along with the tubes connecting it. In this case, the rinsing solution shall be incorporated with the solution contained in the main absorber. Such a device shall not be used for measuring concentrations lower than 30 mg⋅m-3.  Guard bottle, without sintered frit, that can be positioned after the secondary absorber to collect any reagent carry over. SIST EN 1911:2011

Requirements are of course less stringent for parts of sampling system which are downstream the absorbers (pumps, flow rate meters, etc.), but the use of corrosion resistant materials is recommended. 5.2.4 Absorption solution. Chloride-free water of at least grade 2 purity according to EN ISO 3696:1995 shall be used (conductivity less than 100 µS⋅m-1). 5.3 Sampling procedure 5.3.1 Preparation and installation of equipment 5.3.1.1 Sampling location The sampling location is chosen according to EN 15259. 5.3.1.2 Sampling point(s) The sampling point(s) shall be chosen according to EN 15259. SIST EN 1911:2011
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