1、Designation: D6216 12Standard Practice forOpacity Monitor Manufacturers to Certify Conformance withDesign and Performance Specifications1This standard is issued under the fixed designation D6216; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、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. Scope*1.1 This practice covers the procedure for certifying con-tinuous opacity monitors. In the main
3、part of this practice, itincludes design and performance specifications, testprocedures, and quality assurance requirements to ensure thatcontinuous opacity monitors meet minimum design and cali-bration requirements, necessary in part, for accurate opacitymonitoring measurements in regulatory enviro
4、nmental opacitymonitoring applications subject to 10 % or higher opacitystandards. In Annex A1, additional or alternative specificationsare provided for certifying opacity monitors intended for use inapplications where the opacity standard is less than 10 %, orwhere the user expects the opacity to b
5、e less than 10 % andelects to use the more restrictive criteria in Annex A1. In bothcases, the error budgets for the opacity measurements are givenin X1.1.2 This practice applies specifically to the originalmanufacturer, or to those involved in the repair, remanufacture,or resale of opacity monitors
6、.1.3 Test procedures that specifically apply to the variousequipment configurations of component equipment that com-prise either a transmissometer, an opacity monitor, or completeopacity monitoring system are detailed in this practice.1.4 The specifications and test procedures contained in themain p
7、art of this practice have been adopted by reference bythe United States Environmental Protection Agency (USEPA).For each opacity monitor or monitoring system that themanufacturer demonstrates conformance to this practice, themanufacturer may issue a certificate that states that opacitymonitor or mon
8、itoring system conforms with all of the appli-cable design and performance requirements of 40 CFR 60,Appendix B, Performance Specification 1 except those forwhich tests are required after installation.2. Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis ofAt
9、mospheres2.2 U.S. Environmental Protection Agency Document:340 CFR 60 Appendix B, Performance Specification 12.3 Other Documents:ISO/DIS 9004 Quality Management and Quality SystemElements-Guidelines4ANSI/NCSL Z 540-1-1994 Calibration Laboratories andMeasuring Equipment - General Requirements4NIST 26
10、0-116 - Filter calibration procedures53. Terminology3.1 For terminology relevant to this practice, see Terminol-ogy D1356.3.2 Definitions of Terms Specific to This Standard:Analyzer Equipment3.2.1 opacity, nmeasurement of the degree to whichparticulate emissions reduce (due to absorption, reflection
11、, andscattering) the intensity of transmitted photopic light andobscure the view of an object through ambient air, an effluentgas stream, or an optical medium, of a given pathlength.3.2.1.1 DiscussionOpacity (Op), expressed as a percent, isrelated to transmitted light, (T) through the equation:Op 5
12、1 2 T!100!. (1)3.2.2 opacity monitor, nan instrument that continuouslydetermines the opacity of emissions released to the atmo-sphere.3.2.2.1 DiscussionAn opacity monitor includes a trans-missometer that determines the in-situ opacity, a means to1This practice is under the jurisdiction of ASTM Commi
13、ttee D22 on Air Qualityand is the direct responsibility of Subcommittee D22.03 on Ambient Atmospheresand Source Emissions.Current edition approved Oct. 1, 2012. Published November 2012. Originallyapproved in 1998. Last previous edition approved in 2007 as D6216 - 07.DOI:10.1520/D6216-12.2For referen
14、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 U.S. Government Printing Office Superintendent of Documen
15、ts,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.5Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 3460, Gaithersburg, MD 20899-3460.*A S
16、ummary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1correct opacity measurements to equivalent single-pass opacityvalues that would be observed at the pathlength of the emission
17、outlet, and all other interface and peripheral equipment neces-sary for continuous operation.3.2.2.2 DiscussionAn opacity monitor may include thefollowing: (1) sample interface equipment such as filters andpurge air blowers to protect the instrument and minimizecontamination of exposed optical surfa
18、ces, (2) shutters or otherdevices to provide protection during power outages or failureof the sample interface, and (3) a remote control unit tofacilitate monitoring the output of the instrument, initiation ofzero and upscale calibration checks, or control of other opacitymonitor functions.3.2.3 opa
19、city monitor model, na specific transmissometeror opacity monitor configuration identified by the specificmeasurement system design, including: (1) the use of specificlight source, detector(s), lenses, mirrors, and other opticalcomponents, (2) the physical arrangement of optical and otherprincipal c
20、omponents, (3) the specific electronics configurationand signal processing approach, (4) the specific calibrationcheck mechanisms and drift/dust compensation devices andapproaches, and (5) the specific software version and dataprocessing algorithms, as implemented in a particular manu-facturing proc
21、ess, at a particular facility and subject to anidentifiable quality assurance system.3.2.3.1 DiscussionChanging the retro-reflector material orthe size of the retro-reflector aperture is not considered to be amodel change unless it changes the basic attributes of theoptical system.3.2.3.2 Discussion
22、Minor changes to software or dataoutputs may not be considered as a model change provided thatthe manufacturer documents all such changes and provides asatisfactory explanation in a report.3.2.4 opacity monitoring system, nthe entire set of equip-ment necessary to monitor continuously the in-stack o
23、pacity,average the emission measurement data, and permanentlyrecord monitoring results.3.2.4.1 DiscussionAn opacity monitoring system includesat least one opacity monitor with all of its associated interfaceand peripheral equipment and the specific data recordingsystem (including software) employed
24、by the end user. Anopacity monitoring system may include multiple opacity moni-tors and a common data acquisition and recording system.3.2.5 optical density (OD), na logarithmic measure of theamount of incident light attenuated.3.2.5.1 DiscussionOD is related to transmittance andopacity as follows:O
25、D 5 log101/T! 52log10T! 52log101 2 Op!, (2)where Op is expressed as a fraction.3.2.6 transmittance, nthe fraction of incident light withina specified optical region that passes through an opticalmedium.3.2.7 transmissometer, nan instrument that passes lightthrough a particulate-laden effluent stream
26、 and measures in situthe optical transmittance of that light within a specifiedwavelength region.3.2.7.1 DiscussionSingle-pass transmissometers consistof a light source and detector components mounted on oppositeends of the measurement path. Double-pass instruments consistof a transceiver (including
27、 both light source and detectorcomponents) and a reflector mounted on opposite ends of themeasurement path.3.2.7.2 DiscussionFor the purposes of this practice, thetransmissometer includes the following mechanisms (1) meansto verify the optical alignment of the components and (2)simulated zero and up
28、scale calibration devices to check cali-bration drifts when the instrument is installed on a stack orduct.3.2.7.3 DiscussionTransmissometers are sometimes re-ferred to as opacity analyzers when they are configured tomeasure opacity.Analyzer Zero Adjustments and Devices3.2.8 dust compensation, na met
29、hod or procedure forsystematically adjusting the output of a transmissometer toaccount for reduction in transmitted light reaching the detector(apparent increase in opacity) that is specifically due to theaccumulation of dust (that is, particulate matter) on theexposed optical surfaces of the transm
30、issometer.3.2.8.1 DiscussionDust compensation may be included asan optional feature but is not required.3.2.8.2 DiscussionThe dust compensation is determinedrelative to the previous occasion when the exposed optics werecleaned and the dust compensation was reset to zero. Thedetermination of dust acc
31、umulation on surfaces exposed to theeffluent must be limited to only those surfaces through whichthe light beam passes under normal opacity measurement andthe simulated zero device or equivalent mechanism necessaryfor the dust compensation measurement. The determination ofdust compensation is not re
32、quired to include all surfacesexposed to the effluent or dust accumulation.3.2.8.3 DiscussionThe dust accumulation for all of theoptical surfaces included in the dust compensation methodmust actually be measured. Unlike zero drift, which may beeither positive or negative, dust compensation can only
33、reducethe apparent opacity. A dust compensation procedure cancorrect for specific bias and provide measurement resultsequivalent to the clean window condition.3.2.8.4 DiscussionIn those cases where dust compensa-tion is used, the opacity monitor must provide a means todisplay the level of dust compe
34、nsation. Regulatory require-ments may impose a limit on the amount of dust compensationthat can be applied and require that an alarm be activated whenthe limit is reached.3.2.9 external zero device, nan external device for check-ing the zero alignment of the transmissometer by simulatingthe zero opa
35、city condition for a specific installed opacitymonitor.3.2.10 simulated zero device, nan automated mechanismwithin the transmissometer that produces a simulated clear pathcondition or low level opacity condition.3.2.10.1 DiscussionThe simulated zero device is used tocheck zero drift daily or more fr
36、equently and whenevernecessary (for example, after corrective actions or repairs) toD6216 122assess opacity monitor performance while the instrument isinstalled on the stack or duct.3.2.10.2 DiscussionThe proper response to the simulatedzero device is established under clear path conditions while th
37、etransmissometer is optically aligned at the installation path-length and accurately calibrated. The simulated zero device isthen the surrogate, clear path calibration value, while theopacity monitor is in service.3.2.10.3 DiscussionSimulated zero checks do not neces-sarily assess the optical alignm
38、ent, the reflector status (fordouble-pass systems), or the dust contamination level on alloptical surfaces. (See also 6.9.1.)3.2.11 zero alignment, nthe process of establishing thequantitative relationship between the simulated zero device andthe actual clear path opacity responses of a transmissome
39、ter.3.2.12 zero compensation, nan automatic adjustment ofthe transmissometer to achieve the correct response to thesimulated zero device.3.2.12.1 DiscussionThe zero compensation adjustment isfundamental to the transmissometer design and may be inher-ent to its operation (for example, continuous adju
40、stment basedon comparison to reference values/conditions, use of automaticcontrol mechanisms, rapid comparisons with simulated zeroand upscale calibration drift check values, and so forth) or itmay occur each time a calibration check cycle (zero andupscale calibration drift check) is performed by ap
41、plying eitheranalog or digital adjustments within the transmissometer.3.2.12.2 DiscussionFor opacity monitors that do not dis-tinguish between zero compensation and dust compensation,the accumulated zero compensation may be designated as thedust compensation. Regulatory requirements may impose alimi
42、t on the amount of dust compensation that can be appliedand require that an alarm be activated when the limit isreached.3.2.13 zero drift, nthe difference between the opacitymonitor response to the simulated zero device and its nominalvalue (reported as percent opacity) after a period of normalconti
43、nuous operation during which no maintenance, repairs, orexternal adjustments to the opacity monitor took place.3.2.13.1 DiscussionZero drift may occur due to changesin the light source, changes in the detector, variations due tointernal scattering, changes in electronic components, or vary-ing envir
44、onmental conditions such as temperature, voltage orother external factors. Depending on the design of thetransmissometer, particulate matter (that is, dust) deposited onoptical surfaces may contribute to zero drift. Zero drift may bepositive or negative.Calibrations and Adjustments3.2.14 attenuator,
45、 na glass or grid filter that reduces thetransmittance of light.3.2.15 calibration drift, nthe difference between the opac-ity monitor response to the upscale calibration device and itsnominal value after a period of normal continuous operationduring which no maintenance, repairs, or external adjust
46、mentsto the opacity monitor took place.3.2.15.1 DiscussionCalibration drift may be determinedafter determining and correcting for zero drift. For opacitymonitors that include automatic zero compensation or dustcompensation features, calibration drift may be determinedafter zero drift or dust compens
47、ation, or both, are applied.3.2.16 calibration error, nthe sum of the absolute value ofthe mean difference and confidence coefficient for the opacityvalues indicated by an optically aligned opacity monitor(laboratory test) or opacity monitoring system (field test) ascompared to the known values of t
48、hree calibration attenuatorsunder clear path conditions.3.2.16.1 DiscussionThe calibration error indicates thefundamental calibration status of the opacity.3.2.17 external adjustment, neither (1) a physical adjust-ment to a component of the opacity monitoring system thataffects its response or its p
49、erformance, or (2) an adjustmentapplied by the data acquisition system (for example, math-ematical adjustment to compensate for drift) which is externalto the transmissometer and control unit, if applicable.3.2.17.1 DiscussionExternal adjustments are made at theelection of the end user but may be subject to variousregulatory requirements.3.2.18 intrinsic adjustment, nan automatic and essentialfeature of an opacity monitor that provides for the internalcontrol of specific components or adjustment of the opacitymonitor response in a manner c
