1、Designation: D 5149 02 (Reapproved 2008)Standard Test Method forOzone in the Atmosphere: Continuous Measurement byEthylene Chemiluminescence1This standard is issued under the fixed designation D 5149; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes the sampling and continuousanalysis of the ozone content of t
3、he atmosphere at concentra-tions of 20 to 2000 g of ozone/m3(10 ppb (v) to 1 ppm (v).1.2 This test method is limited in application by its sensi-tivity to interferences as described below. This test method isnot suitable for personal sampling because of instrument sizeand sensitivity to vibration an
4、d ambient temperature.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior
5、to use. Some specificprecautionary statements are presented in Section 8.2. Referenced Documents2.1 ASTM Standards:2D 1356 Terminology Relating to Sampling and Analysis ofAtmospheresD 1357 Practice for Planning the Sampling of the AmbientAtmosphereD 1914 Practice for Conversion Units and Factors Rel
6、atingto Sampling and Analysis of AtmospheresD 3249 Practice for General Ambient Air Analyzer Proce-duresD 3670 Guide for Determination of Precision and Bias ofMethods of Committee D22D 5011 Practices for Calibration of Ozone Monitors UsingTransfer StandardsD5110 Practice for Calibration of Ozone Mon
7、itors andCertification of Ozone Transfer Standards Using Ultravio-let PhotometryIEEE/ASTM SI-10 Practice for Use of the InternationalSystem of Units (SI) (the Modernized Metric System)2.2 U.S. Environmental Protection Agency Standards:3EPA-600/4-79-056 Transfer Standards for Calibration ofAirMonitor
8、ing Analyzers for Ozone (NTIS: PB80146871)EPA-600/4-79-057 Technical Assistance Document for theCalibration of Ozone Monitors (NTIS: PB80149552)EPA-600/4-80-050 Evaluation of Ozone Calibration Tech-niques (NTIS: PB81118911)EPA-600/4-83-003 Performance Test Results and Compara-tive Data for Designate
9、d Reference and Equivalent Meth-ods for Ozone (NTIS: PB83166686)2.3 Code of Federal Regulations:340-CFR-Part 53.203. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D 1356 and Practice D 1914.Anexplanation of units, symbols and conversion factors may
10、befound in Practice E 380.3.2 Definitions of Terms Specific to This Standard:3.2.1 absolute ultra-violet photometera photometerwhose design, construction and maintenance is such that it canmeasure the absorbance caused by ozone mixtures withoutreference to external absorption standards. Given a valu
11、e forthe absorption coefficient of ozone at 253.7 nm and a readingfrom the absolute ultraviolet photometer, ozone concentrationscan be calculated with accuracy. Measurements by an absoluteultraviolet photometer should be made on prepared ozonemixtures free from interferences.3.2.2 primary standarda
12、standard directly defined andestablished by some authority, against which all secondarystandards are compared.3.2.3 secondary standarda standard used as a means ofcomparison, but checked against a primary standard.3.2.4 standardan accepted reference sample or deviceused for establishing measurement
13、of a physical quantity.3.2.5 transfer standarda type of secondary standard. It isa transportable device or apparatus which, together withoperational procedures, is capable of reproducing a sampleconcentration or producing acceptable assays of sample con-centrations.1This test method is under the jur
14、isdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved April 1, 2008. Published July 2008. Originallyapproved in 1990. Last previous edition approved in 2002 as D 5149 - 02.2For referen
15、ced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from National Technical Information Service (NTIS), 5285 PortR
16、oyal Rd., Springfield, VA 22161, http:/www.ntis.gov.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Significance and Use4.1 Air quality standards for ozone have been promulgatedby government authorities to protect the health and w
17、elfare ofthe public. Though ozone itself is a toxic material, it is oftencomplex organic compounds that cause the symptoms of smogsuch as tearing and burning eyes. However, ozone is thepredominant oxidant and is much more easily monitored thanorganic species. Since ozone concentrations are also corr
18、elatedwith other photochemical oxidant levels, it is the substance thatis specified in air quality standards and regulations.5. Interferences5.1 Any aerosol that scatters light or that may deposit on thephotomultiplier window constitutes a negative interference tothis test method. Particulate matter
19、 can be removed with apoly-tetrafluoroethylene (PTFE) membrane filter; however,this filter may become contaminated and scrub ozone. It isimportant to check the ozone-inertness of these filters periodi-cally. (See Practice D5110.)5.2 Atmospheric humidity constitutes a positive interfer-ence to this t
20、est method when calibrations are conducted withdry span gas mixtures. The range of interference reported istabulated in Annex A2 of this test method.45.3 Reduced sulfur compounds have not been found toconstitute positive interferences to this test method.56. Measurement Principle6.1 This measurement
21、 principle is based on the photometricdetection of the chemiluminescence (light produced by achemical reaction) resulting from the flameless gas phasereaction of ethylene (C2H4) with ozone (O3). The sample gascontaining ozone is mixed with excess ethylene (bottle gas,C.P. or better, supplied to the
22、instrument) to generate excitedformaldehyde (HCHO*) molecules. The excited formaldehydemolecules decay immediately to the ground energy state,releasing energy in the form of light in the 300 to 600 nmregion, with maximum intensity at 430 nm. The light energy ismeasured by a photosensor (frequently a
23、 photomultiplier tube)that produces an output current proportional to the lightintensity. The current, converted to voltage and conditioned asnecessary by the electronic circuits, becomes the analyzersoutput signal.7. Apparatus7.1 A schematic of the instrument is given in Fig. 1. Thechemiluminescent
24、 reaction cell is constructed of materials inertto ozone, for example, PTFE-coated metal, borosilicate glass,fused silica.7.2 The input filter is installed in front of the sample line toprevent aerosols or particulate matter from entering the mea-suring system. PTFE filters with pore sizes between 0
25、.5 and 5.0m should be used. The filter should be kept clean sinceaccumulated material on the filter may catalyze the breakdownof ozone into oxygen. Depressed ozone responses have beenobserved immediately after filter changes for periods up to onehour.7.3 Internal lines and fittings in the sample str
26、eam prior tothe reaction call are made of PTFE or other ozone-inertmaterial.7.4 Due to the flammability of ethylene, some manufactur-ers suggest the use of ethylene-carbon dioxide blends insteadof 100 % ethylene when the monitoring device is to be used ina public facility. This blend is a liquefied,
27、 nonflammablemixture of approximately 9 % ethylene and 91 % CO2. Thechemiluminescent reaction is the same; however, gas consump-tion is considerably higher as a result of the reduced ethyleneconcentration. The proportions of ethylene and CO2suppliedby the blend change as the mixture is consumed from
28、 thecylinder. Since this changes the sensitivity of the analyzer, theanalyzer should be recalibrated periodically. The concentrationof ethylene supplied by the blend is also changed by thetemperature of the cylinder, which must be maintained constantduring use.8. Safety Hazards8.1 Beyond the normal
29、precautions necessary when workingwith any instrument that contains high voltages and flammablegases, this test method raises the need for some specialconsiderations. When calibrating the instrument, vent theexcess gas mixture, especially if it contains high concentrationsof ozone, through a charcoa
30、l filter. This will avoid contamina-tion of the work area around the instrument with ozone, whichat the concentrations likely to be encountered in this testmethod, can induce headaches and occasionally nausea.9. Sampling9.1 Sampling the atmosphere should be done in accordancewith the guidelines in P
31、ractices D 1357 and D 3249. Thesepractices point out the need to avoid sites which are closer than50 m distance from traffic which could give rise to transienthydrocarbon and nitrogen oxides effects on ambient ozonelevels.4Kleindienst, T. E., Hudgens, E. E., Smith, D. F., McElroy, F. F., and Bufalin
32、i,J. J., “Comparison of Chemiluminescence and Ultraviolet Ozone Monitor Re-sponses in the Presence of Humidity and Photochemical Pollutants,” Journal of Airand Waste Management Assoc., Vol 43, 1993, p 213.5Kleindienst, T.C., McIver, C.D., Ollison, W. M., “A Study of Interferences inAmbient Ozone Mon
33、itors,” VIP-74, Measurement of Toxic and Related AirPollutants, Air the initial response may exceed the high spanconcentration by up to 10 %. An overshoot, which relaxes tothe high span level over a few hours, may appear when theanalyzer samples dry span gas for extended periods and seemsto predomin
34、ate in instruments operating on ethylene/CO2mixtures. (See 2.2 and 7.4.)10.3 The response of the chemiluminescent analyzer isaffected by the oxygen content of the sample gas. Thus, ifsynthetic zero air is used, its oxygen content shall closelymatch the normal atmospheric concentrations. (See 2.2.)11
35、. Procedures11.1 Site the monitor with consideration of Practice D 1357.11.2 Sample the atmosphere with a probe having nonreac-tive inside walls, PTFE or glass for example. The probe shallbe kept clean and shall be leak-tested. The sample flow into theinstrument shall be free of particulate matter a
36、nd the PTFEfilter, which is used to achieve this, shall be kept clean. Thedegree to which the concentration of ozone in the sampleatmosphere is changed by the probe and filter shall be checkedby passing calibration gases to the monitor directly and thenvia the probe and filter and observing the diff
37、erence inresponse.11.3 Avoid situations where the analyzer will be exposed torapid and frequent changes of ambient temperature. Where, forexample, the monitor is operated in a small sampling stationwhich is cooled or heated by a high-capacity system, it shall beshielded from direct air flow from the
38、 system. Many instru-ments are well compensated for slow changes in ambienttemperature, but do not respond well to the rapid changes oftenfound in small air monitoring stations, which may exceed1C/min.11.4 Choose a data recording system that matches the outputof the monitor. In the case of a data lo
39、gger or telemetry system,the sampling interval and data analysis method shall detect andreport instrument malfunctions such as excessive variability inthe output, spikes and so forth, and shall not merely averagethem away. The dynamic range and precision of the recorder ordata logger shall be wide e
40、nough to accommodate the range ofconcentrations anticipated. In the case of ozone in the ambientatmosphere, the peak levels can be ten times higher thantypical summer day levels. Automatic multi-ranging may helpto retain accuracy at low levels while allowing for occasionalhigh levels to be measured
41、and recorded.11.4.1 All recording or data logging devices shall positivelyidentify calibration values. This can be achieved as simply asusing a chart recording and writing the information on thechart. An automatic data logger shall include a status signalrecorded along with the instrument output inf
42、ormation whichlabels calibration points as different from ambient measure-ments.11.5 See Practice D 3249 for general guidelines on operat-ing ambient air analyzers.12. Precision and Bias12.1 The median precision at 20 % and 80 % of the upperrange limit for six instruments is reported as 60.001 ppm (
43、v)O3in Annex A1. Interferent bias reported in Annex A2 rangesup to +18 % at high absolute humidity for some instrumentscalibrated with dry span gases. Calibrations with wet span gasat typical ambient humidities may be used to reduce this bias.5,713. Keywords13.1 chemiluminescent; continuous analyzer
44、; ethylene;ozone6Butcher, S., and Ruff, R., “Effect of Residence Time on Analysis of Atmo-spheric Nitrogen Oxides and Ozone,” Anal. Chem. , Vol 43, p. 1890, 1971.7Parrish, D.D., Fehsenfeld, F.C., “Methods for Gas-Phase Measurements ofOzone, Ozone Precursors, and Aerosol Precursors,” Atmospheric Envi
45、ronment 34:1921 (2000).D 5149 02 (2008)3ANNEXES(Mandatory Information)ANNEXESA1. PERFORMANCE SPECIFICATIONSTABLE A1 Performance Specifications for Ethylene Chemiluminescent Ozone Monitor (40 CFR Part 53.20)AParameters EPA SpecificationManufacturers TestBEPA RetestCInstrumentNumberRange MedianInstrum
46、entNumberDRange MedianNoise 0 % URLE0.005 ppm 6 0.0010.001 0.000 5 0.0000.001 0.00080 % URL 0.005 ppm 6 0.0010.002 0.002 5 0.0010.003 0.002LDLE0.01 ppm 6 0.0090.011 0.010 5 0.0110.013 0.012H2O InterferenceF+0.02 ppm 6 0.0010.002 0.001 5 0.0010.001 0.000H2S InterferenceF+0.02 ppm 6 0.0010.001 0.000 5
47、 0.0010.001 0.000CO2Interference +0.02 ppm 6 0.0010.006 0.000 5 0.0000.001 0.000Total interferenceA0.06 ppm 6 0.0010.007 0.002 5 0.0010.002 0.001Zero driftA12 h24 h+0.02 ppm+0.02 ppm660.0010.0040.0010.0030.0010.001550.0010.0040.0010.0010.001Span driftA20 % URL80 % URL+20 %+5 %660.483.411.212.872.361
48、.33552.36.961.623.362.82.17Lag time 20 min 6 0.11.0 0.2 5 0.10.2 0.2Rise time 15 min 6 0.22.0 1.0 5 0.81.2 1.1Fall time 15 min 6 0.32.0 1.0 5 1.32.0 1.5Precision 20 % URL 0.01 ppm 6 0.0010.002 0.001 5 0.0000.001 0.00180 % URL 0.01 ppm 6 0.0010.002 0.001 5 0.0010.006 0.001AAverage of absolute values.
49、BAverage values for each instrument model from manufacturers application for equivalency determination.CAverage values for each instrument model from EPA post designation tests.DIndividual instrument testing is recommended; four of the five instruments purchased through normal procurement procedures required component replacement beforeretest program could be completed.EUpper Range Limit; Lower Detection Limit.FTested in the absence of ozone; see Annex A2 for the effects of water vapor in the presence of ozone.A2. HUMIDITY INTERFERENCETABLE
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