1、Designation: D5149 02 (Reapproved 2016)Standard Test Method forOzone in the Atmosphere: Continuous Measurement byEthylene Chemiluminescence1This standard is issued under the fixed designation D5149; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se 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 the
3、 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 and
4、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 to
5、 use. Some specificprecautionary statements are presented in Section 8.2. Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis ofAtmospheresD1357 Practice for Planning the Sampling of the AmbientAtmosphereD1914 Practice for Conversion Units and Factors Relating
6、 toSampling and Analysis of AtmospheresD3249 Practice for General Ambient Air Analyzer Proce-duresD3670 Guide for Determination of Precision and Bias ofMethods of Committee D22D5011 Practices for Calibration of Ozone Monitors UsingTransfer StandardsD5110 Practice for Calibration of Ozone Monitors an
7、dCertification 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 of AirMonitoring Ana
8、lyzers 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 Designated Refer
9、ence 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 D1356 and Practice D1914.Anexplanation of units, symbols and conversion factors may befound i
10、n Practice IEEE/ASTM SI-10.3.2 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 val
11、ue 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.1This test method is under the jurisdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.03 on AmbientAtmospheres and Source Emissions.Current edition approved Oct. 1, 2016. Published October 2016. Originallyapproved in 1990. Last p
14、revious edition approved in 2008 as D5149 02 (2008).DOI: 10.1520/D5149-02R16.2For referenced 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 ont
15、he ASTM website.3Available from National Technical Information Service (NTIS), 5285 PortRoyal Rd., Springfield, VA 22161, http:/www.ntis.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.5 transfer standarda type of secondary st
16、andard. It isa transportable device or apparatus which, together withoperational procedures, is capable of reproducing a sampleconcentration or producing acceptable assays of sample con-centrations.4. Significance and Use4.1 Air quality standards for ozone have been promulgatedby government authorit
17、ies to protect the health and welfare 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 ozo
18、ne concentrations are also correlatedwith 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
19、test method. Particulate matter 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 p
20、ositive interfer-ence to this test 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. Measuremen
21、t Principle6.1 This measurement 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
22、P. or better, supplied to the 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
23、 by a photosensor (frequently a 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
24、 in Fig. 1. Thechemiluminescent 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 fi
25、lters with pore sizes between 0.5 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
26、 and fittings in the sample stream 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 facil
27、ity. This blend is a liquefied, 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
28、as the mixture is consumed from 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. Safet
29、y Hazards8.1 Beyond the normal 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 concentrat
30、ions4Kleindienst, T. E., Hudgens, E. E., Smith, D. F., McElroy, F. F., and Bufalini,J. J., “Comparison of Chemiluminescence and Ultraviolet Ozone Monitor Re-sponses in the Presence of Humidity and Photochemical Pollutants,” Journal of theAir and Waste Management Assoc., Vol. 43, 1993, p 213.5Kleindi
31、enst, T.C., McIver, C.D., Ollison, W. M., “A Study of Interferences inAmbient Ozone Monitors,” 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
32、 appear when theanalyzer samples dry span gas for extended periods and seemsto predominate 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, it
33、s oxygen content shall closelymatch the normal atmospheric concentrations. (See 2.2.)11. Procedures11.1 Site the monitor with consideration of Practice D1357.11.2 Sample the atmosphere with a probe having nonreac-tive inside walls, PTFE or glass for example. The probe shallbe kept clean and shall be
34、 leak-tested. The sample flow into theinstrument shall be free of particulate matter and 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
35、 gases to the monitor directly and thenvia the probe and filter and observing the difference 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
36、or heated by a high-capacity system, it shall beshielded from direct air flow from the 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
37、 data recording system that matches the outputof the monitor. In the case of a data logger 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 averageth
38、em away. The dynamic range and precision of the recorder ordata logger shall be wide enough 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
39、retain accuracy at low levels while allowing for occasionalhigh levels to be measured 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
40、data logger shall include a status signalrecorded along with the instrument output information whichlabels calibration points as different from ambient measure-ments.11.5 See Practice D3249 for general guidelines on operatingambient air analyzers.12. Precision and Bias12.1 The median precision at 20
41、 % and 80 % of the upperrange limit for six instruments is reported as 60.001 ppm (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
42、 used to reduce thisbias.5,76Butcher, 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,” At
43、mospheric Environment, Vol.34, 2000, pp. 19211957.D5149 02 (2016)313. Keywords13.1 chemiluminescent; continuous analyzer; ethylene;ozoneANNEXES(Mandatory Information)A1. PERFORMANCE SPECIFICATIONSTABLE A1.1 Performance Specifications for Ethylene Chemiluminescent Ozone Monitor (40 CFR Part 53.20)APa
44、rameters EPA SpecificationManufacturers TestBEPA RetestCInstrumentNumberRange MedianInstrumentNumberDRange 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.
45、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 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 ppm660.0010.0040.0010.0030.001
46、0.001550.0010.0040.0010.0010.001Span driftA20 % URL80 % URL+20 %+5 %660.483.411.212.872.361.33552.36.961.623.362.82.17Lag 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 0.0000.0
47、01 0.00180 % URL 0.01 ppm 6 0.0010.002 0.001 5 0.0010.006 0.001AAverage of absolute values.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 i
48、s 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
49、 ozone.A2. HUMIDITY INTERFERENCETABLE A2.1 Reported Humidity InterferenceApproximateAbsoluteHumidity (ppm)EquivalentTemperature at50 % RH (C)Wet/Dry RatioAof ChemiluminescentResponseNumber ofInstrumentsRange ofRatiosMedianRatio5 000 7 7 1.011.04 1.0310 000 18 7 1.031.07 1.0415 000 24 9 1.071.12 1.0820 000 29 7 1.061.12 1.0825 000 33 5 1.071.15 1.1230 000 37 4 1.101.18 1.11ALinear Regression of all data: Ratio (Wet/Dry) = 1.0105 + 3.975 106ppm H2O r2= 0.71. Source: “Water Vapor Effect on Ozone Reference Methods,” 29 December19
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