SIST EN 1076:2010
(Main)Workplace exposure - Procedures for measuring gases and vapours using pumped samplers - Requirements and test methods
Workplace exposure - Procedures for measuring gases and vapours using pumped samplers - Requirements and test methods
This European Standard specifies performance requirements and test methods under prescribed laboratory conditions for the evaluation of pumped samplers used in conjunction with an air sampling pump and of procedures using these samplers for the determination of gases and vapours in workplace atmospheres. This European Standard is applicable to pumped samplers and measuring procedures using these samplers in which sampling and analysis are carried out in separate stages. This European Standard is not applicable to: - pumped samplers which are used for the direct determination of concentrations, for example, length-of- stain detector tubes; - samplers which rely on sorption into a liquid, and subsequent analysis of the solution (bubblers).
Exposition am Arbeitsplatz - Messung von Gasen und Dämpfen mit pumpenbetriebenen Probenahmeeinrichtungen - Anforderungen und Prüfverfahren
Diese Europäische Norm legt Anforderungen an die Leistungsfähigkeit und Prüfverfahren für die Evaluierung
von pumpenbetriebenen Probenehmern unter vorgegebenen Laborbedingungen fest, die in Verbindung mit
einer Luftsammelpumpe verwendet werden, sowie Verfahren, die diese Probenehmer zur Bestimmung von
Gasen und Dämpfen in der Arbeitsplatzatmosphäre verwenden.
Diese Europäische Norm gilt für pumpenbetriebene Probenehmer und Messverfahren, die diese
Probenehmer, bei denen Probenahme und Analyse in getrennten Schritten vorgenommen werden,
verwenden.
Diese Europäische Norm gilt nicht für:
- pumpenbetriebene Probenehmer, die zur direkten Konzentrationsbestimmung verwendet werden, z. B.
Prüfröhrchen mit Längenanzeige;
- Probenehmer, deren Funktionsweise auf Sorption in einer Flüssigkeit und anschließender Analyse der
Lösung beruht (Gaswaschflaschen).
Zusätzliche Prüfungen, um festzustellen, ob die Leistungsmerkmale der pumpenbetriebenen Probenehmer
durch irgend welche Umwelteinflüsse beeinträchtigt werden, die bei der Felderprobung angetroffen werden
können, werden in den Anhängen D und E beschrieben.
Exposition sur les lieux de travail - Procédures pour le mesurage des gaz et vapeurs à l'aide de dispositifs de prélèvement par pompage - Exigences et méthodes d'essai
La présente Norme européenne spécifie les exigences de performances et les méthodes d’essai, dans des conditions de laboratoires prescrites, pour l’évaluation des dispositifs de prélèvement par pompage employés conjointement à une pompe de prélèvement d’air, ainsi que pour l’évaluation des procédures utilisant ces dispositifs de prélèvement pour la détermination des gaz et des vapeurs dans les atmosphères des lieux de travail.
La présente Norme européenne est applicable aux dispositifs de prélèvement par pompage et aux procédures de mesurage utilisant ces dispositifs de prélèvement pour lesquels le prélèvement et l’analyse sont effectués au cours d’étapes séparées.
La présente Norme européenne ne s'applique pas :
aux dispositifs de prélèvement par pompage utilisés pour la détermination directe des concentrations, par exemple des tubes détecteurs à plage colorée ;
aux dispositifs de prélèvement basés sur l'adsorption dans un liquide suivie de l’analyse de la solution (barboteurs).
Des essais supplémentaires, destinés à vérifier si les caractéristiques de fonctionnement du dispositif de prélèvement par pompage sont affectées ou non par l'étendue plus grande des influences environnementales pouvant être rencontrées sur le terrain, sont décrits dans l’Annexe D et l’Annexe E.
Izpostavljenost na delovnem mestu - Postopki za merjenje plinov in par z vzorčevalniki s črpanjem - Zahteve in preskusne metode
Ta evropski standard določa zahteve za zmogljivost in preskusne metode pod predpisanimi laboratorijskimi pogoji za vrednotenje vzorčevalnikov s črpanjem, ki se uporabljajo v povezavi s črpalko za vzorčenje zraka, in postopkov, pri katerih se uporabljajo ti vzorčevalniki za določevanje plinov in par v ozračju na delovnem mestu. Ta evropski standard velja za vzorčevalnike s črpanjem in merilne postopke z uporabo teh vzorčevalnikov, v katerih vzorčevanje in analiza potekata v ločenih stopnjah. Ta evropski standard ne velja za: - vzorčevalnike s črpanjem, ki se uporabljajo za neposredno ugotavljanje koncentracij, na primer detektorske cevi z dolžino barvila; - vzorčevalnike, ki se opirajo na sorpcijo v tekočino in nadaljnjo analizo raztopine (s pripomočki za ustvarjanje mehurčkov).
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Exposition am Arbeitsplatz - Messung von Gasen und Dämpfen mit pumpenbetriebenen Probenahmeeinrichtungen - Anforderungen und PrüfverfahrenExposition sur les lieux de travail - Procédures pour le mesurage des gaz et vapeurs à l'aide de dispositifs de prélèvement par pompage - Exigences et méthodes d'essaiWorkplace exposure - Procedures for measuring gases and vapours using pumped samplers - Requirements and test methods13.040.30Kakovost zraka na delovnem mestuWorkplace atmospheresICS:Ta slovenski standard je istoveten z:EN 1076:2009SIST EN 1076:2010en,fr,de01-februar-2010SIST EN 1076:2010SLOVENSKI
STANDARDSIST EN 1076:1998/AC:1998SIST EN 1076:19981DGRPHãþD
SIST EN 1076:2010
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 1076
December 2009 ICS 13.040.30 Supersedes EN 1076:1997English Version
Workplace exposure - Procedures for measuring gases and vapours using pumped samplers - Requirements and test methods
Exposition sur les lieux de travail - Procédures pour le mesurage des gaz et vapeurs à l'aide de dispositifs de prélèvement par pompage - Exigences et méthodes d'essai Exposition am Arbeitsplatz - Messung von Gasen und Dämpfen mit pumpenbetriebenen Probenahmeeinrichtungen - Anforderungen und Prüfverfahren This European Standard was approved by CEN on 1 November 2009.
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.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1076:2009: ESIST EN 1076:2010
EN 1076:2009 (E) 2 Contents Page Foreword .3Introduction .41Scope .52Normative references .53Terms and definitions .54Symbols and abbreviated terms .55Types of samplers .76Requirements .76.1General .76.2Sampler requirements .76.3Measuring procedure requirements . 107General test conditions . 127.1Reagents . 127.2Apparatus . 127.3Independent method . 137.4Generation of the calibration gas mixture . 138Test methods . 148.1General . 148.2Sampler test methods . 148.3Measuring procedure test methods . 158.4Uncertainty of measurement . 229Test report . 23Annex A (informative)
Examples for the determination of the breakthrough volume . 24A.1Direct method . 24A.2Chromatographic method . 24Annex B (informative)
Estimation of uncertainty of measurement . 26B.1General . 26B.2Uncertainty associated with sampled air volume . 26B.3Uncertainty associated with sampling efficiency . 28B.4Uncertainty associated with sample storage and transportation . 28B.5Uncertainty associated with method recovery . 28B.6Uncertainty associated with method variability . 32B.7Calculation of combined standard uncertainty . 35Annex C (informative)
Example of estimation of expanded uncertainty . 37Bibliography . 41 SIST EN 1076:2010
EN 1076:2009 (E) 3 Foreword This document (EN 1076:2009) has been prepared by Technical Committee CEN/TC 137 “Assessment of workplace exposure to chemical and biological agents”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2010, and conflicting national standards shall be withdrawn at the latest by June 2010. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 1076:1997. The major technical changes between this European Standard and the previous edition are as follows: a) adaptation of the framework for assessing the performance of procedures for measuring gases and vapours against the general requirements for the performance of procedures for measuring chemical agents in workplace atmospheres as specified in EN 482; b) revision of the calculation model for the uncertainty of measurement to comply with EN 482 and ENV 13005; c) modification of the classification scheme for sampler types; d) deletion of the informative annexes on the evaluation of pumped samplers by means of field tests. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. SIST EN 1076:2010
EN 1076:2009 (E) 4 Introduction This European Standard provides a framework for assessing the performance of procedures for measuring gases and vapours against the general requirements for the performance of procedures for measuring chemical agents in workplace atmospheres as specified in EN 482. It enables manufacturers and users of pumped samplers and developers and users of procedures for measuring gases and vapours to adopt a consistent approach to method validation. SIST EN 1076:2010
EN 1076:2009 (E) 5 1 Scope This European Standard specifies performance requirements and test methods under prescribed laboratory conditions for the evaluation of pumped samplers used in conjunction with an air sampling pump and of procedures using these samplers for the determination of gases and vapours in workplace atmospheres. This European Standard is applicable to pumped samplers and measuring procedures using these samplers in which sampling and analysis are carried out in separate stages. This European Standard is not applicable to: pumped samplers which are used for the direct determination of concentrations, for example, length-of-stain detector tubes; samplers which rely on sorption into a liquid, and subsequent analysis of the solution (bubblers). 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 482:2006, Workplace atmospheres — General requirements for the performance of procedures for the measurement of chemical agents EN 838, Workplace atmospheres — Diffusive samplers for the determination of gases and vapours — Requirements and test methods EN 1232:1997, Workplace atmospheres — Pumps for personal sampling of chemical agents — Requirements and test methods EN 1540:1998, Workplace atmospheres — Terminology EN ISO 8655-2, Piston-operated volumetric apparatus — Part 2: Piston pipettes (ISO 8655-2:2002) EN ISO 8655-6, Piston-operated volumetric apparatus — Part 6: Gravimetric methods for the determination of measurement error (ISO 8655-6:2002) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 482:2006 and EN 1540:19981) apply. 4 Symbols and abbreviated terms For the purposes of this document, the following symbols and abbreviations apply. NOTE See 8.4 and Annex B for symbols used in conjunction with uncertainty of measurement only. CRM certified reference material
1) EN 1540:1998 is currently subject to revision. Until the revised EN is published the definitions given in EN 482:2006 take precedence. SIST EN 1076:2010
EN 1076:2009 (E) 6 LV limit value ma1 mass of analyte desorbed from tube blank, in micrograms (µg) ma2 mass of analyte desorbed from spiked tube, in micrograms (µg) ma,lt maximum mass uptake of analyte in a leak test performed on a sealed sampler used for making
measurements for comparison with a long-term limit value, in milligrams (mg) ma,st maximum mass uptake of analyte in a leak test performed on a sealed sampler used for making
measurements for comparison with a short-term limit value, in milligrams (mg) 1m& mass loss from permeation tube, in micrograms per minute (µg/min) Ma molar mass of analyte, in grams per mole (g/mol) n number of replicate samples pat actual pressure of the test atmosphere sampled, in kilopascals (kPa) R recovery Ran analytical recovery RH relative humidity of the test atmosphere sampled, in percent (%) tH hold-up time of the unretained substance, in minutes (min) ts sampling time, in minutes (min) Tat temperature of the test atmosphere sampled, in Kelvins (K) V0 volume of the test atmosphere sampled, in litres (l) VH gas hold-up volume (dead volume) VR uncorrected retention volume (VR)' corrected retention volume v& flow rate into the exposure chamber, for example, in litres per minute (l/min) va volumetric air flow rate, for example, in litres per minute (l/min) βa mass concentration of the analyte in the calibration gas mixture, in milligrams per cubic metre (mg/m³) βa,R mean mass concentration of the analyte recovered from the test gas atmosphere, in milligrams per
cubic metre (mg/m³) βcg mass concentration of the calibration gas mixture, in milligrams per cubic metre (mg/m³) ϑat temperature of the test atmosphere sampled, in degrees Celsius (°C) SIST EN 1076:2010
EN 1076:2009 (E) 7 Κv coefficient of variation (CV)2) ρ LV,lt long-term limit value given as volume concentration, in milligrams per cubic metre (mg/m³) ρ LV,st short-term limit value given as volume concentration, in milligrams per cubic metre (mg/m³) φa volume fraction of the analyte, in microlitres per litre (µl/l) 5 Types of samplers Samplers for gases and vapours can be divided into type A samplers and type B samplers: Type A samplers rely on sorption onto a solid or onto a support impregnated with a reagent, desorption with solvent, and subsequent analysis of the desorbate. They are usually made of glass, are thermally sealed, and consist of two beds of sorbent in series, i.e. with a back-up section, and contain an active sorbent (e.g. activated carbon) or a support impregnated with reagent. Type B samplers rely on sorption onto a solid or onto a support impregnated with a reagent, thermal desorption, and analysis of the desorbate. They are usually made of glass or metal, are sealed with removable fittings and consist of one or more beds of sorbent (e.g. porous polymer resin). 6 Requirements NOTE If there is no procedure for measuring a particular chemical agent which meets the requirements of this European Standard, a procedure whose performance is nearest to the specified requirements should be used. 6.1 General Some requirements (see 6.2) shall be verified once for each type of sampler. Other requirements (see 6.3) shall be verified for each combination sampler/chemical agent. It is the responsibility of the manufacturer to meet the requirements specified in 6.2. It is also the responsibility of the manufacturer or the developer of the measuring procedure to meet the requirements specified in 6.3 when use of a sampler for measurement of a particular gas or vapour is claimed. NOTE No useful performance requirements can be given for the effect of interferents (with the exception of water vapour). The effect of interferents is difficult to predict for a non-ideal sorbent without adsorption isotherm data on mixed systems which is normally unavailable. 6.2 Sampler requirements 6.2.1 Flow resistance When tested in accordance with 8.2.1, at least 95 % of samplers shall have a back pressure less than the appropriate maximum value indicated in Table 1. A minimum of 20 samplers shall be tested.
2) The predecessor term "relative standard deviation" is deprecated. See also ISO 3534-1:2006, 2.38, Note 2. SIST EN 1076:2010
EN 1076:2009 (E) 8 Table 1 — Maximum back pressures Type of sampler Maximum back pressure kPa Type A – sorbent tubes, solvent desorption ≤ 10 Type A – impregnated filters ≤ 10 Type B – sorbent tubes, thermal desorption ≤ 3,5 6.2.2 Sampler leak test (for Type B samplers) When tested in accordance with 8.2.2, for substances with a long-term limit value the maximum leakage, i.e. the maximum mass uptake of analyte above the blank value (see 6.3.2.3), shall be less than ma,lt calculated according to Equation (1), in milligrams (mg), as follows: )10 0,012401,0(313-lta,ltLV,×××=ρm (1) where ma,lt is the maximum mass uptake of analyte in a leak test performed on a sealed sampler used for making measurements for comparison with a long-term limit value; ρ LV,lt is the long-term limit value of the substance given as volume concentration, in milligrams per cubic metre (mg/m³); 240
is the reference period, in minutes (min); 0,01
is the nominal minimum flow rate for type B samplers, in litres per minute (l/min); 10-3 is a factor applied to convert the nominal minimum flow rate from litres per minute (l/min) to cubic metres per minute (m³/min); 1/3
is a factor applied to calculate the maximum permitted leakage. When tested in accordance with 8.2.2, for substances with a short-term limit value the maximum leakage, i.e. the maximum mass uptake of analyte above the blank value (see 6.3.2.3), shall be less than ma,st calculated according to Equation (2), in milligrams (mg), as follows: )100,01155,0(313-sta,stLV,×××=ρm (2) where ma,st is the maximum mass uptake of analyte in a leak test performed on a sealed sampler used for making measurements for comparison with a short-term limit value; ρ LV,st is the short-term limit value of the substance given as volume concentration, in milligrams per cubic metre (mg/m³); 15
is the reference period, in minutes (min); 0,01
is the nominal minimum flow rate for type B samplers, in litres per minute (l/min); SIST EN 1076:2010
EN 1076:2009 (E) 9 10-3
is a factor applied to convert the nominal minimum flow rate from litres per minute (l/min) to cubic metres per minute (m³/min); 1/3
is a factor applied to calculate the maximum permitted leakage. 6.2.3 Shelf life (for impregnated supports) The manufacturer shall specify the shelf life of the sampler when stored in its original package. During this period the sampler shall fulfil all requirements. 6.2.4 Sample identification (for commercially available sorbent tubes and impregnated filters) The sampler shall have a suitable area for sample identification by the user. 6.2.5 Marking Samplers shall be marked with at least the following: manufacturer’s name; product identification; indication of the direction of air flow, if necessary; batch identification; shelf life (if applicable); number of this European Standard. If required due to limited space, the marking may be placed on the packaging of the sampler. However, the manufacturer’s name, product identification and direction of air flow shall be indicated on the sampler. 6.2.6 Instructions for use The instructions for use supplied with the sampler shall be in the language(s) of the country where the sampler is to placed on the market. They shall contain at least the following information: a) designated use (general purpose for a number of gases and vapours or, specific, for a particular gas or vapour, see 6.1); b) blank value (only when used for a particular gas or vapour, see 6.1); c) directions for proper handling of the sampler, including opening and closing; d) general information on the principle of use, for example, sorbent type, reaction of the reagent impregnated solid, desorption method; e) information on storage and transport; f) information on health or environmental hazards and method of disposal. SIST EN 1076:2010
EN 1076:2009 (E) 10 6.3 Measuring procedure requirements 6.3.1 Sampling procedure requirements 6.3.1.1 General Sampling conditions (sample volume, flow rate and sampling time) shall be established according to the LV assigned to the compounds of interest, e.g. short-term limit value, long-term limit value or both. 6.3.1.2 Sample volume The recommended sample volume shall be less than two-third of the breakthrough volume measured in accordance with 8.3.1.3. 6.3.1.3 Air flow rate 6.3.1.3.1 Impregnated filters When tested according 8.3.1.4, the maximum air flow rate shall be 90 % of the flow rate at which the breakthrough volume drops by 5 %. 6.3.1.3.2 Thermal desorption samplers (Type B samplers) A minimum air flow rate shall be established according to the test in 8.3.1.5. 6.3.1.4 Storage conditions after sampling The storage conditions after sampling shall be specified. When tested in accordance with 8.3.1.6, the mean value of the recovery after storage shall not differ by more than 10 % from the value before storage. 6.3.2 Analytical procedure requirements 6.3.2.1 Analytical quantification limit The quantification limit shall be lower than or equal to the calculated mass of analyte that would be collected for the minimum air sample volume specified in the measuring procedure at the following concentrations: 0,1 LV for substances with long-term limit value; 0,5 LV for substances with short-term limit value only. 6.3.2.2 Analytical recovery When tested in accordance with 8.3.2.2, the analytical recovery Ran shall be: for Type A samplers: Ran ≥ 75 % with Κv ≤ 10 % at each loading; for Type B samplers: Ran ≥ 95 % with Κv ≤ 10 % at each loading. 6.3.2.3 Blank value When tested in accordance with 8.3.2.3 the blank value shall be less than one-tenth of the calculated mass collected by the sampler during the recommended sampling time at the recommended air flow rate and at concentrations of: SIST EN 1076:2010
EN 1076:2009 (E) 11 0,1 LV for substances with long-term limit value; 0,5 LV for substances with short-term limit value only. Where it is known that the blank value is significant and varies between batches of samplers, it shall be checked regularly. NOTE 1 In order to eliminate any contamination which could occur during storage before use, Type B samplers should be cleaned by taking them through the thermal desorption procedure. This cleaning process should be carried out as close as possible to the time when the samplers will be used. NOTE 2 In order to obtain acceptable values for the quantification limit of the method, the blank value of the sampling media should be as low as technically possible. 6.3.3 Expanded uncertainty When tested in accordance with 8.3 the expanded uncertainty, calculated in accordance with 8.4, shall meet the requirements given in EN 482. The expanded uncertainty requirement shall be met from 10 °C to 40 °C and at relative humidities from 20 % to 80 %. 6.3.4 Method description 6.3.4.1 Scope of the measuring procedure The scope of the measuring procedure shall give information about the following: a) principle of the method; b) chemical agents covered by the measuring procedure; c) analytical technique used; d) working ranges; e) chemical agents for which the measuring procedure is known to be adequate but not completely validated according to this European Standard, especially in case of compounds of the same chemical family or homologous series; f) chemical agents for which the measuring procedure is known to be inadequate; g) any known interferences. 6.3.4.2 Method performance The measuring procedure shall give information about method performance, including the following: a) the chemical agents for which measurement method has been shown to be effective; b) the range of concentrations of chemical agents in air, sample volume and range of environmental conditions over which the measurement method has been shown to meet the performance criteria for expanded uncertainty prescribed in EN 482; c) the quantification limit of the analytical method for chemical agents of interest; d) full details of any known interferences, including suitable and sufficient information on how to minimise their effects. SIST EN 1076:2010
EN 1076:2009 (E) 12 6.3.4.3 Apparatus and reagents The measuring procedure shall: a) specify that the sampler complies with the provisions of this European Standard; b) contain a requirement that the sampling pumps used comply with the provisions given in EN 1232 and specify any characteristics of the sampling pumps additionally required; c) define the required characteristics of analytical instruments to be used; d) specify the quality of the reagents to be used. 6.3.4.4 Safety information The measuring procedure shall provide suitable and sufficient information on the safety hazards associated with the reagents and equipment used in the procedure. 7 General test conditions 7.1 Reagents Use reagents of analytical grade, where possible. 7.2 Apparatus 7.2.1 Usual laboratory apparatus and the following: 7.2.2 A dynamic system for generating, pre-mixing and delivering a known concentration of a test gas or vapour in air (see EN ISO 6145-1, EN ISO 6145-4 and EN ISO 6145-6), including at least: an exposure chamber constructed of inert materials such as glass or polytetrafluorethylene (PTFE), through which the generated test atmosphere is passed, of sufficient capacity to accommodate simultaneously at least six test samplers and six samplers of one independent method (see 7.3) positioned in such a manner that there is no interference between each sampler; provisions for measuring, controlling and varying the air flow rate through the chamber and the concentration, temperature and relative humidity of the calibration gas mixture. NOTE It is also possible to use a smaller exposure chamber and to carry out repeat experiments to obtain at least six pairs of data. 7.2.3 Appropriate sampling pumps which meet the performance requirements of EN 1232. 7.2.4 Flowmeter(s), calibrated, suitable over the range from 10 ml/min to 2 000 ml/min, with a measurement uncertainty less than ± 2 %. 7.2.5 Micropipettes or syringes, for applying known volumes of standard solutions, complying with the requirements of EN ISO 8655-2 and with a calibration checked in accordance with EN ISO 8655-6. 7.2.6 Instruments for analysing the gas, vapour or a characteristic reaction product collected by either the test sampler or an independent sampling method. SIST EN 1076:2010
EN 1076:2009 (E) 13 7.3 Independent method The concentration of the generated calibration gas mixture in the exposure chamber shall be verified as follows: a) by an independent method, which has been validated using an established protocol, for example, a diffusive sampler method, bubbler method or a different sorbent tube method; or b) by using an independently calibrated on-line instrument, e.g. a flame ionization detector, or an infrared spectrometer. If a diffusive sampler procedure is used as the independent method, the method shall comply with all requirements of EN 838. 7.4 Generation of the calibration gas mixture 7.4.1 General Set up a calibration gas mixture at the concentration and values of temperature, relative humidity, etc. specified in the appropriate test methods in Clause 8. Ensure that the flow rate into the exposure chamber exceeds the combined sampling rate of all samplers by at least 25 %. 7.4.2 Calibration gas mixture Calculate the mass concentration of the calibration gas mixture, βcg, given in milligrams per cubic metre (mg/m³), from the test atmosphere generation parameters. For example, for a permeation cell system, the delivered mass concentration is:
vm&&1cg=β (3) where 1m& is the mass loss from permeation tube, in micrograms per minute (µg/min); v& is the flow rate into the exposure chamber, for example, in litres per minute (l/min). NOTE The example does not give a preference for permeation systems for generating calibration gas mixtures. Determine the mean mass concentration of the test atmosphere within the exposure chamber experimentally using the results of the independent method described in 7.3. A correction may be applied for any known bias in the independent method.
Compare the determined mean mass concentration with the calculated value. If the experimentally determined value is within ± 10 % of the calculated value of the mass concentration of the delivered test atmosphere, take the calculated value as the true value of the delivered mass concentration. If this requirement is not met, then adjustments shall be made or an alternative generation method shall be used or the independent method shall be verified. If it is not possible to calculate a mass concentration of the calibration gas, for example, for reactive gases, the value determined by the independent method shall be used as the true value. SIST EN 1076:2010
EN 1076:2009 (E) 14 8 Test methods 8.1 General If it is known in advance that a certain type of sampler is unaffected by an environmental influence then the relevant tests in 8.3.3.2 to 8.3.3.4 may be modified to examine only the factors likely to have an influence. There are different levels of evaluation. These levels are specified as follows: a) level 1: A measuring procedure evaluated for the analyte of interest in accordance with the normative part of this European Standard; b) level 2: A measuring procedure deemed to be compliant with the normative part of this European Standard on the basis that the analyte of interest is an analogue within a homologous s
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