2, with the note that at high

stack gas temperatures (greater than 250 °C (480 °F)), water-cooled probes may be required to control the probe exit temperature to 42°±10 °C (108±18 °F). 2.1.3 Precollector Cyclone. Borosilicate glass following the construction details shown in Air Pollution Technical Document- 0581, "Construction Details of Isokinetic Source-Sampling Equipment". NOTE: The tester shall use the cyclone when the stack gas moisture is greater than 10 percent. The tester shall not use the precollector cyclone under other. less severe conditions. 2.1.4 Filter Heating System. Any heating (or cooling) system capable of maintaining a sample gas temperature at the exit end of the filter holder during sampling at 42 °±10° C (108°±18° F). Install a temperature gauge capable of measuring temperature within 3° C (5.4° F) at the exit side of the filter holder so that the sensing tip of the temperature METHOD 9 40 CFR PART 60 APPENDIXA Environmental Protection Agency, EPA Pt. 60, App. A, Meth. 9 EC16NO91.248 Where: K4=0.003464 mm Hg-m 3/ml-°K for metric units. =0.002676 in. Hg-ft ³/ml-°R for English units. 6.7.2 Calculation from Intermediate Values. EC01JN92.153 where: Ks=4.320 for metric units. =0.09450 for English units 6.8 Acceptable Results. If 90 percent < I <110 percent, the results are acceptable. If the results are low in comparison to the standards and I is beyond the acceptable range, the Administrator may opt to accept the results. Use Citation 4 in the Bibliography of Method 5 to make judgments. Otherwise, reject the results and repeat the test. 6.9 Stack Gas Velocity and Volumetric Flow Rate. Calculate the average stack gas velocity and volumetric flow rate, if needed, using data obtained in this method and equations in Sections 5.2 and 5.3 of Method 2. 6.10 Relative Error (RE) for QA Audit Samples. Same as in Method 6, Section 6.4. 7. Bibliography 1. Atmospheric Emissions from Sulfuric Acid Manufacturing Processes. U.S. DHEW. PHS, Division of Air Pollution. Public Health Service Publication No. 999-AP-13. Cincinnati, OH. 1965. 2. Corbett, P. F. The Determination of SO₂ and SO₃ in Flue Gases. Journal of the Institute of Fuel. 24:237-243. 1961. 3. Martin, Robert M. Construction Details of Isokinetic Source Sampling Equipment. Environmental Protection Agency. Research Triangle Park, NC. Air Pollution Control Office Publication No. APTD-0581. April, 1971. 4. Patton, W. F. and J. A. Brink, Jr. New Equipment and Techniques for Sampling Chemical Process Gases. Journal of Air Pollution Control Association. 13:162. 1963. 5. Rom, J. J. Maintenance, Calibration, and Operation of Isokinetic Source-Sampling Equipment. Office of Air Programs. Environmental Protection Agency. Research Triangle Park, NC. APTD-0576. March, 1972. 6. Hamil. H. F. and D. E. Camann. Collaborative Study of Method for Determination of Sulfur Dioxide Emissions from Stationary Sources (Fossil Fuel-Fired Steam Generators). Environmental Protection Agency. Research Triangle Park. NC. EPA-650/4-74-024. December, 1973. 7. Annual Book of ASTM Standards. Part 31: Water. Atmospheric Analysis. pp. 40-42. American Society for Testing and Materials. Philadelphia, Pa. 1974. METHOD 9-VISUAL DETERMINATION OF THE OPACITY OF EMISSIONS FROM STATIONARY SOURCES Many stationary sources discharge visible emissions into the atmosphere; these emissions are usually in the shape of a plume. This method involves the determination of plume opacity by qualified observers. The method includes procedures for the training and certification of observers, and procedures to be used in the field for determination of plume opacity. The appearance of a plume as viewed by an observer depends upon a number of variables, some of which may be controllable and some of which may not be controllable in the field. Variables which can be controlled to an extent to which they no longer exert a significant influence upon plume appearance include: Angle of the observer with respect to the plume: angle of the observer with respect to the sun; point of observation of attached and detached steam plume: and angle of the observer with respect to a plume emitted from a rectangular stack with a large length to width ratio. The method includes specific criteria applicable to these variables. Other variables which may not be controllable in the field are luminescence and color contrast between the plume and the background against which the plume is viewed. These variables exert an influence upon the appearance of a plume as viewed by an observer, and can affect the ability of the observer to accurately assign opacity values to the observed plume. Studies of the theory of plume opacity and field studies have demonstrated that a plume is most visible and presents the greatest apparent opacity when viewed against a contrasting background. It follows from this, and is confirmed by field trials, that the opacity of a plume, viewed under conditions where a contrasting background is present can be assigned with the greatest degree of accuracy. However, the potential for a positive error is also the greatest when a plume is viewed under such contrasting conditions. Under conditions presenting a less contrasting background, the apparent opacity of a plume is less and approaches zero as the color and luminescence contrast decrease toward zero. As a result, significant negative bias and negative errors can be made when a plume is viewed under less contrasting conditions. A negative bias decreases rather than Increases the possibility that a plant operator will be cited for a violation of opacity standards due to observer error. Studies have been undertaken to determine the magnitude of positive errors which can be made by qualified observers while reading plumes under contrasting conditions and using the procedures set forth in this method. The results of these studies (field trials) which Involve a total of 769 sets of 25 readings each are as follows: (1) For black plumes (133 sets at a smoke generator). 100 percent of the sets were read with a positive error I of less than 7.5 percent opacity: 99 percent were read with a positive error of less than 5 percent opacity. (2) For white plumes (170 sets at a smoke generator, 168 sets at a coal-fired power plant. 298 sets at a sulfuric acid plant), 99 percent of the sets were read with a positive error of less than 7.5 percent opacity: 95 percent were read with a positive error of less than 5 percent opacity. The positive observational error associated with an average of twenty-five readings is therefore established. The accuracy of the method must be taken into account when determining possible violations of applicable opacity standards. 1. Principle and Applicability 1.1 Principle. The opacity of emissions from stationary sources is determined visually by a qualified observer. 1.2 Applicability. This method Is applicable for the determination of the opacity of emissions from stationary sources pursuant to $60.11(b) and for qualifying observers for visually determining opacity of emissions. 2. Procedures The observer qualified in accordance with section 3 of this method shall use the following procedures for visually determining the opacity of emissions: 2.1 Position. The qualified observer shall stand at a distance sufficient to provide a clear view of the emissions with the sun ortented in the 140° sector to his back. Consistent with maintaining the above requirement, the observer shall, as much as possible, make his observations from a position such that his line of vision is approximately perpendicular to the plume direction, and when observing opacity of emissions from rectangular outlets (e.g., roof monitors, open I For a set, positive error = average opacity determined by observers' 25 observations-average opacity determined from transmissometer's 25 recordings. baghouses, noncircular stacks), approximately perpendicular to the longer axis of the outlet. The observer's line of sight should not include more than one plume at a time when multiple stacks are involved, and in any case the observer should make his observations with his line of sight perpendicular to the longer axis of such a set of multiple stacks (e.g., stub stacks on baghouses). 2.2 Field Records. The observer shall record the name of the plant. emission location. type facility. observer's name and affillation, a sketch of the observer's position relative to the source, and the date on a field data sheet (Figure 9-1). The time, estimated distance to the emission location, approximate wind direction, estimated wind speed, description of the sky condition (presence and color of clouds). and plume background are recorded on a field data sheet at the time opacity readings are initiated and completed. 2.3 Observations. Opacity observations shall be made at the point of greatest opacity in that portion of the plume where condensed water vapor is not present. The observer shall not look continuously at the plume, but Instead shall observe the plume momentarily at 15-second Intervals. 2.3.1 Attached Steam Plumes. When condensed water vapor is present within the plume as it emerges from the emission outlet. opacity observations shall be made beyond the point in the plume at which condensed water vapor is no longer visible. The observer shall record the approximate distance from the emission outlet to the point In the plume at which the observations are made. 2.3.2 Detached Steam Plume. When water vapor in the plume condenses and becomes visible at a distinct distance from the emission outlet, the opacity of emissions should be evaluated at the emission outlet prior to the condensation of water vapor and the formation of the steam plume. 2.4 Recording Observations. Opacity observations shall be recorded to the nearest 5 percent at 15-second intervals on an observational record sheet. (See Figure B-2 for an example.) A minimum of 24 observations shall be recorded. Each momentary observation recorded shall be deemed to represent the average opacity of emissions for a 15-second period. 2.5 Data Reduction. Opacity shall be determined as an average of 24 consecutive observations recorded at 15-second intervals. Divide the observations recorded on the record sheet into sets of 24 consecutive observations. A set is composed of any 24 consecutive observations. Sets need not be consecutive in time and In no case shall two sets overlap. For each set of 24 observations. calculate the average by summing the opacity of the 24 observations and dividing this sum Environmental Protection Agency, EPA by 24. If an applicable standard specifies an averaging time requiring more than 24 observations, calculate the average for all observations made during the specified time perlod. Record the average opacity on a record sheet. (See Figure 9-1 for an example.) 3. Qualifications and Testing 3.1 Certification Requirements. To receive certification as a qualified observer, a candidate must be tested and demonstrate the ability to assign opacity readings in 5 percent increments to 25 different black plumes and 25 different white plumes, with an error not to exceed 15 percent opacity on any one reading and an average error not to exceed 7.5 percent opacity in each category. Candidates shall be tested according to the procedures described in section 3.2. Smoke generators used pursuant to section 3.2 shall be equipped with a smoke meter which meets the requirements of section 3.3. The certification shall be valid for a period of 6 months, at which time the qualification procedure must be repeated by any observer in order to retain certification. 3.2 Certification Procedure. The certification test consists of showing the candidate a complete run of 50 plumes-25 black plumes and 25 white plumes-generated by a smoke generator. Plumes within each set of 25 black and 25 white runs shall be presented in random order. The candidate assigns an opacity value to each plume and records his observation on a suitable form. At the completion of each run of 50 readings. the score of the candidate is determined. If a candidate fails to qualify. the complete run of 50 readings must be repeated in any retest. The smoke test may be administered as part of a smoke school or training program. and may be preceded by training or familiarization runs of the smoke generator during which candidates are shown black and white plumes of known opacity. 3.3 Smoke Generator Specifications. Any smoke generator used for the purposes of section 3.2 shall be equipped with a smoke meter installed to measure opacity across the diameter of the smoke generator stack. The smoke meter output shall display Instack opacity based upon a pathlength equal to the stack exit diameter, on a full 0 to 100 percent chart recorder scale. The smoke meter optical design and performance shall meet the specifications shown in Table 9-1. The smoke meter shall be callbrated as prescribed in section 3.3.1 prior to the conduct of each smoke reading test. At the completion of each test, the zero and span drift shall be checked and if the drift exceeds ±1 percent opacity, the condition shall be corrected prior to conducting any subsequent test runs. The smoke meter shall be demonstrated, at the time of installation, to meet the specifications listed in Table 9-1. This demonstration shall be repeated following any subsequent repair or replacement of the photocell or associated electronic circuitry including the chart recorder or output meter, or every 6 months, whichever occurs first. TABLE 9-1-SMOKE METER DESIGN AND PERFORMANCE SPECIFICATIONS Parameter Specification a. Light source Incandescent lamp operated at nominal rated voltage. b. Spectral response of Photopic (daylight spectral rephotocell. sponse of the human eye-Citation 3). c. Angle of view 15 maximum total angle. d. Angle of projection 18 maximum total angle. B. Calibration error +3% opacity, maximum. f. Zero and span drift +1% opacity, 30 minutes g. Response time 5 seconds. 3.3.1 Calibration. The smoke meter is callbrated after allowing a minimum of 30 minutes warmup by alternately producing simulated opacity of 0 percent and 100 percent. When stable response at 0 percent or 100 percent is noted, the smoke meter is adjusted to produce an output of 0 percent or 100 percent. as appropriate. This calibration shall be repeated until stable 0 percent and 100 percent readings are produced without ad- Justment. Simulated 0 percent and 100 percent opacity values may be produced by alternately switching the power to the light source on and off while the smoke generator Is not producing smoke. 3.3.2 Smoke Meter Evaluation. The smoke meter design and performance are to be evaluated as follows: 3.3.2.1 Light Source. Verify from manufacturer's data and from voltage measurements made at the lamp. as installed, that the lamp is operated within +5 percent of the nominal rated voltage. 3.3.2.2 Spectral Response of Photocell. Verify from manufacturer's data that the photocell has a photopic response; i.e., the spectral sensitivity of the cell shall closely approximate the standard spectral-luminosity curve for photopic vision which is referenced in (b) of Table 9-1. EC01JN92.154 FIGURE 9-2-OBSERVATION RECORD Page of Company Location Test Number Date. Observer Type facility Point of emissions 280 Environmental Protection Agency, EPA Pt. 60, App. A, Meth. 9 Seconds Steam plume (check if applicable) Hr. Min. Comments 0 15 30 45 Attached Detached 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 16 16 17 18 19 20 21 22 23 24 25 26 27 28 29 FIGURE 9-2-OBSERVATION RECORD-(CONTINUED) Page of Company Observer Location Type facility Test Number Point of emissions Date Seconds Steam plume (check if applicable) Hr. Min. Comments 0 15 30 45 Attached Detached 30 Pt. 60, App. A, Meth. 9 40 CFR Ch. I (7-1-99 Edition) Seconds Steam plume (check if applicable) Hr. Min. Comments 0 15 30 45 Attached Detached 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 3.3.2.3 Angle of View. Check construction geometry to ensure that the total angle of view of the smoke plume. as seen by the photocell, does not exceed 15°. The total angle of view may be calculated from: 0=2 tan- 'd/2L, where 0=total angle of view: d=the sum of the photocell diameter+the diameter of the limiting aperture; and L=the distance from the photocell to the limiting apercure. The limiting aperture is the point In the path between the photocell and the smoke plume where the angle of view is most restricted. In smoke generator smoke meters this is normally an orifice plate. 3.3.2.4 Angle of Projection. Check construction geometry to ensure that the total angle of projection of the lamp on the smoke plume does not exceed 15 °. The total angle of projection may be calculated from: 0=2 tan- 'd/2L. where B= total angle of projection; de the sum of the length of the lamp Pt. 60, App. A, Alt. Meth. filament + the diameter of the limiting aperture; and L= the distance from the lamp to the limiting aperture. 3.3.2.5 Calibration Error. Using neutraldensity filters of known opacity, check the error between the actual response and the theoretical linear response of the smoke meter. This check is accomplished by first calibrating the smoke meter according to 3.3.1 and then Inserting a series of three neutral-density filters of nominal opacity of 20, 50. and 75 percent in the smoke meter pathlength. Filters calibrated within +2 percent shall be used. Care should be taken when inserting the filters to prevent stray light from affecting the meter. Make a total of five nonconsecutive readings for each filter. The maximum error on any one reading shall be 3 percent opacity. 3.3.2.6 Zero and Span Drift. Determine the zero and span drift by calibrating and operating the smoke generator in a normal manner over a 1-hour period. The drift is measured by checking the zero and span at the end of this period. 3.3.2.7 Response Time. Determine the response time by producing the series of five simulated 0 percent and 100 percent opacity values and observing the time required to reach stable response. Opacity values of 0 percent and 100 percent may be simulated by alternately switching the power to the light source off and on while the smoke generator is not operating. 4. Bibliography. 1. Air Pollution Control District Rules and Regulations, Los Angeles County Air Pollution Control District, Regulation IV, Prohibitions. Rule 50. 2. Weisburd. Melvin I., Field Operations and Enforcement Manual for Air, U.S. Environmental Protection Agency, Research Triangle Park, NC. APTD-1100. August 1972. pp. 4.1-4.36. 3. Condon, E.U., and Odishaw, H., Handbook of Physics, McGraw-Hill Co., New York, NY, 1958, Table 3.1, p. 6-52. ALTERNATE METHOD 1-DETERMINATION OF THE OPACITY OF EMISSIONS FROM STA- TIONARY SOURCES REMOTELY BY LIDAR This alternate method provides the quantitative determination of the opacity of an emissions plume remotely by a mobile lidar system (laser radar; Light Detection and Ranging). The method includes procedures for the calibration of the lidar and procedures to be used in the field for the lidar determination of plume opacity. The lidar is used to measure plume opacity during either day or nighttime hours because It contains its own pulsed light source or transmitter. The operation of the lidar is not dependent upon ambient lighting conditions (light, dark. sunny or cloudy). The lidar mechanism or technique is applicable to measuring plume opacity at numerous wavelengths of laser radiation. However, the performance evaluation and calibration test results given in support of this method apply only to a lidar that employs a ruby (red light) laser [Reference 5.1]. 1. Principle and Applicability 1.1 Principle. The opacity of visible emissions from stationary sources (stacks, roof vents, etc.) is measured remotely by a mobile lidar (laser radar). 1.2 Applicability. This method is applicable for the remote measurement of the opacity of visible emissions from stationary sources during both nighttime and daylight conditions, pursuant to 40 CFR 60.11(b). It is also applicable for the calibration and performance verification of the mobile lidar for the measurement of the opacity of emissions. A performance/design specification for a basic lidar system is also incorporated into this method. 1.3 Definitions. Azimuth angle: The angle in the horizontal plane that designates where the laser beam is pointed. It is measured from an arbitrary fixed reference line in that plane. Backscatter: The scattering of laser light in a direction opposite to that of the incldent laser beam due to reflection from particulates along the beam's atmospheric path which may include a smoke plume. Backscatter signal: The general term for the lidar return signal which results from laser light being backscattered by atmospheric and smoke plume particulates. Convergence distance: The distance from the lidar to the point of overlap of the lidar receiver's fleld-of-view and the laser beam. Elevation angle: The angle of inclination of the laser beam referenced to the horizontal plane. Far region: The region of the atmosphere's path along the lidar line-of-sight beyond or behind the plume being measured. Lidar: Acronym for Light Detection and Ranging. Lidar range: The range or distance from the lidar to a point of interest along the lidar line-of-sight. Near region: The region of the atmospheric path along the lidar line-of-sight between the lidar's convergence distance and the plume being measured. Opacity: One minus the optical transmittance of a smoke plume, screen target, etc. Pick Interval: The time or range intervals in the lidar backscatter signal whose minimum average amplitude is used to calculate opacity. Two pick intervals are required, one In the near region and one in the far region. Plume: The plume being measured by lidar. Plume signal: The backscatter signal resulting from the laser light pulse passing through a plume. METHOD 10 40 CFR PART 60 APPENDIXA Environmental Protection Agency, EPA Pt. 60, App. A, Meth. 10 runs and the results of each should be recorded. The requirements of Section 3.3.1 must be fulfilled for each of the three runs. Once the conditions of the annual callbration are fulfilled the lidar shall be subjected to the routine verification for three separate complete runs. The requirements of Section 3.3.2 must be fulfilled for each of the three runs and the results should be recorded. The Administrator may request that the results of the performance evaluation be submitted for review. 5. References 5.1 The Use of Lidar for Emissions Source Opacity Determination, U.S. Environmental Protection Agency. National Enforcement Investigations Center, Denver, CO. EPA-330/ 1-79-003-R. Arthur W. Dybdahl, current edition INTIS No. PB81-246662]. 5.2 Field Evaluation of Mobile Lidar for the Measurement of Smoke Plume Opacity. U.S. Environmental Protection Agency, National Enforcement Investigations Center, Denver, CO. EPA/NEIC-TS-128, February 1976. 5.3 Remote Measurement of Smoke Plume Transmittance Using Lidar, C. S. Cook, G. W. Bethke, W. D. Conner (EPA/RTP). Applied Optics 11, pg 1742. August 1972. 5.4 Lidar Studies of Stack Plumes in Rural and Urban Environments, EPA-650/4- 73-002. October 1973. 5.5 American National Standard for the Safe Use of Lasers ANSI Z 136.1-176. March 8, 1976. 5.6 U.S. Army Technical Manual TB MED 279. Control of Hazards to Health from Laser Radiation, February 1969. 5.7 Laser Institute of America Laser Safety Manual, 4th Edition. 5.8 U.S. Department of Health, Education and Welfare, Regulations for the Administration and Enforcement of the Radiation Control for Health and Safety Act of 1968, January 1976. 5.9 Laser Safety Handbook, Alex Mallow. Leon Chabot, Van Nostrand Reinhold Co., 1978. METHOD 10-DETERMINATION OF CARBON MON- OXIDE EMISSIONS FROM STATIONARY SOURCES 1. Principle and Applicability 1.1 Principle. An integrated or continuous gas sample is extracted from a sampling point and analyzed for carbon monoxide (CO) content using a Luft-type nondispersive infrared analyzer (NDIR) or equivalent. 1.2 Applicability. This method is applicable for the determination of carbon monoxide emissions from stationary sources only when specified by the test procedures for determining compliance with new source performance standards. The test procedure will indicate whether a continuous or an integrated sample is to be used. 2. Range and Sensitivity 2.1 Range. 0 to 1,000 ppm. 2.2 Sensitivity. Minimum detectable concentration is 20 ppm for a 0 to 1,000 ppm span. 3. Interferences Any substance having a strong absorption of infrared energy will interfere to some extent. For example, discrimination ratios for water (H2O) and carbon dioxide (CO₂ ) are 3.5 percent H2O per 7 ppm CO and 10 percent CO2 per 10 ppm CO. respectively, for devices measuring in the 1,500 to 3,000 ppm range. For devices measuring in the 0 to 100 ppm range, interference ratios can be as high as 3.5 percent H2O per 25 ppm CO and 10 percent CO₂ per 50 ppm CO. The use of silica gel and ascarite traps will alleviate the major Interference problems. The measured gas volume must be corrected if these traps are used. 4. Precision and Accuracy 4.1 Precision. The precision of most NDIR analyzers is approximately +2 percent of span. 4.2 Accuracy. The accuracy of most NDIR analyzers is approximately +5 percent of span after calibration. 5. Apparatus 5.1 Continuous Sample (Figure 10-1). 5.1.1 Probe. Stainless steel or sheathed Pyrex1 glass, equipped with a filter to remove particulate matter. 5.1.2 Air-Cooled Condenser or Equivalent. To remove any excess moisture. 5.2 Integrated Sample (Figure 10-2). 5.2.1 Probe. Stainless steel or sheathed Pyrex glass, equipped with a filter to remove particulate matter. 5.2.2 Air-Cooled Condenser or Equivalent. To remove any excess moisture. 5.2.3 Valve. Needle valve, or equivalent, to adjust flow rate. 5.2.4 Pump. Leak-free diaphragm type, or equivalent, to transport gas. 5.2.5 Rate Meter. Rotameter, or equivalent, to measure a flow range from 0 to 1.0 liter per min (0.035 cfm). 5.2.6 Flexible Bag. Tedlar, or equivalent, with a capacity of 60 to 90 liters (2 to 3 ft 3). Leak-test the bag in the laboratory before using by evacuating bag with a pump followed by a dry gas meter. When evacuation is complete, there should be no flow through the meter. 5.2.7 Pitot Tube. Type S, or equivalent, attached to the probe so that the sampling rate can be regulated proportional to the stack gas velocity when velocity is varying with the time or a sample traverse is conducted. 5.3 Analysis (Figure 10-3). I Mention of trade names or specific products does not constitute endorsement by the Environmental Protection Agency. Pt. 60, App. A, Meth. 10 5.3.1 Carbon Monoxide Analyzer. Nondispersive infrared spectrometer, or equivalent. This instrument should be demonstrated, preferably by the manufacturer, to meet or exceed manufacturer's specifications and those described in this method. 5.3.2 Drying Tube. To contain approximately 200 g of silica gel. 5.3.3 Calibration Gas. Refer to section 6.1. 5.3.4 Filter. As recommended by NDIR manufacturer. 40 CFR Ch. I (7-1-99 Edition) EC01JN92.179 EC01JN92.177 6.2 Silica Gel. Indicating type, 6 to 16 mesh, dried at 175 °C (347 °F) for 2 hours. 6.3 Ascarite. Commercially available. EC01JN92.178 5.3.5 CO₂ Removal Tube. To contain approximately 500 g of ascarite. 5.3.6 Ice Water Bath. For ascarite and silica gel tubes. 5.3.7 Valve. Needle valve. or equivalent, to adjust flow rate 5.3.8 Rate Meter. Rotameter or equivalent to measure gas flow rate of 0 to 1.0 liter per min (0.035 cfm) through NDIR. 5.3.9 Recorder (optional). To provide permanent record of NDIR readings. 6. Reagents 6.1 Calibration Gases. Known concentration of CO in nitrogen (N₂) for instrument span, prepurified grade of N₂ for zero, and two additional concentrations corresponding approximately to 60 percent and 30 percent span. The span concentration shall not exceed 1.5 times the applicable source performance standard. The calibration gases shall be certified by the manufacturer to be within +2 percent of the specified concentration. 7. Procedure 7.1 Sampling. 7.1.1 Continuous Sampling. Set up the equipment as shown in Figure 10-1 making sure all connections are leak free. Place the probe in the stack at a sampling point and purge the sampling line. Connect the analyzer and begin drawing sample into the analyzer. Allow 5 minutes for the system to stabilize. then record the analyzer reading as required by the test procedure. (See section7.2 and 8). CO2 content of the gas may be determined by using the Method 3 integrated sample procedure, or by weighing the ascarite CO2 removal tube and computing CO₂ concentration from the gas volume sampled and the weight gain of the tube. 7.1.2 Integrated Sampling. Evacuate the flexible bag. Set up the equipment as shown In Figure 10-2 with the bag disconnected. Place the probe in the stack and purge the sampling line. Connect the bag. making sure that all connections are leak free. Sample at a rate proportional to the stack velocity. CO2 content of the gas may be determined by using the Method 3 integrated sample procedures, or by weighing the ascarite CO2 removal tube and computing CO2 concentration from the gas volume sampled and the weight gain of the tube. 7.2 CO Analysis. Assemble the apparatus as shown in Figure 10-3, calibrate the instrument, and perform other required operations as described In section B. Purge analyzer with N₂ prior to introduction of each sample. Direct the sample stream through the instrument for the test period, recording the readings. Check the zero and span again after the test to assure that any drift or malfunction is detected. Record the sample data on Table 10-1. 8. Calibration Assemble the apparatus according to Figure 10-3. Generally an instrument requires a warm-up period before stability is obtained. Follow the manufacturer's instructions for specific procedure. Allow a minimum time of 1 hour for warm-up. During this time check Environmental Protection Agency, EPA the sample conditioning apparatus, i.e., filter. condenser, drying tube, and CO₂ removal tube. to ensure that each component is in good operating condition. Zero and calibrate the instrument according to the manufacturer's procedures using, respectively, nitrogen and the calibration gases. TABLE 10-1-FIELD DATA Comments Location Test Date Operator Clock time Rotameter setting, liters per minute (cubic feet per minute) 9. Calculation Calculate the concentration of carbon monoxide in the stack using Equation 10-1. Eq. 10-1 Where: Coo stack=Concentration of CO in stack, ppm by volume (dry basis). Coo NDIR=Concentration of CO measured by NDIR analyzer, ppm by volume (dry basis). Fco₂=Volume fraction of CO₂ in sample. i.e., percent CO₂ from Orsat analysis divided by 100. 10. Alternative Procedures 10.1 Interference Trap. The sample conditioning system described In Method 10A, sections 2.1.2 and 4.2, may be used as an alternative to the silica gel and ascarite traps. 11. Bibliography 1. McElroy. Frank, The Intertech NDIR-CO Analyzer, Presented at 11th Methods Conference on Air Pollution, University of California, Berkeley. CA. April 1, 1970. 2. Jacobs, M. B., et al., Continuous Determination of Carbon Monoxide and Hydrocarbons in Air by a Modified Infrared Analyzer, J. Air Pollution Control Association, 9(2): 110-114. August 1959. 3. MSA LIRA Infrared Gas and Liquid Analyzer Instruction Book, Mine Safety Appliances Co., Technical Products Division, Pittsburgh, PA. 4. Models 215A, 315A, and 415A Infrared Analyzers, Beckman Instruments, Inc., Beckman Instructions 1635-B, Fullerton, CA. October 1967. 5. Continuous CO Monitoring System. Model A5611, Intertech Corp., Princeton. NJ. 6. UNOR Infrared Gas Analyzers, Bendix Corp., Ronceverte, WV Pt. 60, App. A, Meth. 10 ADDENDA A. PERFORMANCE SPECIFICATIONS FOR NDIR CARBON MONOXIDE ANALYZERS Range (minimum) 0-1000 ppm. Output (minimum) 0-10mV. Minimum detectable sensi- 20 ppm. tivity. Rise time, 90 percent (max- 30 seconds. imum). Fall time, 90 percent (max- 30 seconds. imum). Zero drift (maximum) 10% in 8 hours. Span drift (maximum) 10% in 8 hours. Precision (minimum) +2% of full scale. Noise (maximum) ±1% of full scale. Linearity (maximum deviation) 2% of full scale. Interference rejection ratio CO₂-1000 to 1, HO-500 to 1. B. Definitions of Performance Specifications. Range- The minimum and maximum measurement limits. Output- Electrical signal which is proportional to the measurement; Intended for connection to readout or data processing devices. Usually expressed as millivolts or milliamps full scale at a given impedance. Full scale- The maximum measuring limit for a given range. Minimum detectable sensitivity- The smallest amount of input concentration that can be detected as the concentration approaches zero. Accuracy- The degree of agreement between a measured value and the true value; usually expressed as + percent of full scale. Time to 90 percent response- The time interval from a step change in the input concentration at the instrument inlet to a reading of 90 percent of the ultimate recorded concentration. Rise Time (90 percent)-The interval between initial response time and time to 90 percent response after a step increase in the inlet concentration. Fall Time (90 percent)-The Interval between initial response time and time to 90 percent response after a step decrease in the inlet concentration. Zero Drift- The change in instrument output over a stated time period, usually 24 hours, of unadjusted continuous operation when the input concentration is zero; usually expressed as percent full scale. Span Drift- The change in instrument output over a stated time period. usually 24 hours, of unadjusted continuous operation when the input concentration is a stated upscale value: usually expressed as percent full scale. Precision- The degree of agreement between repeated measurements of the same concentration, expressed as the average deviation of the single results from the mean. Noise-Spontaneous deviations from a mean output not caused by input concentration changes. Pt. 60, App. A, Meth. 10A 40 CFR Ch. I (7-1-99 Edition) Linearity-The maximum deviation between an actual instrument reading and the reading predicted by a straight line drawn between upper and lower calibration points. METHOD 10A-DETERMINATION OF CARBON MONOXIDE EMISSIONS IN CERTIFYING CONTIN- UOUS EMISSION MONITORING SYSTEMS AT PE- TROLEUM REFINERIES 1. Applicability and Principle 1.1 Applicability. This method applies to the measurement of carbon monoxide (CO) at petroleum refineries. This method serves as the reference method in the relative accuracy test for nondispersive Infrared (NDIR) CO continuous emission monitoring systems (CEMS's) that are required to be installed in petroleum refineries on fluid catalytic cracking unit catalyst regenerators [40 CFR Part 60.105(a)(2)]. 1.2 Principle. An integrated gas sample is extracted from the stack. passed through an alkaline permanganate solution to remove sulfur and nitrogen oxides, and collected in a Tedlar bag. The CO concentration in the sample is measured spectrophotometrically using the reaction of CO with p-sulfaminobenzoic acid. 1.3 Range and Sensitivity. 1.3.1 Range. Approximately 3 to 1800 ppm CO. Samples having concentrations below 400 ppm are analyzed at 425 nm, and samples having concentrations above 400 ppm are analyzed at 600 nm. 1.3.2 Sensitivity. The detection limit is 3 ppm based on three times the standard deviation of the mean reagent blank values. 1.4 Interferences. Sulfur oxides, nitric oxide, and other acid gases Interfere with the colorimetric reaction. They are removed by passing the sampled gas through an alkaline potassium permanganate scrubbing solution. Carbon dioxide (CO2) does not interfere, but, because it Is removed by the scrubbing solution, its concentration must be measured independently and an appropriate volume correction made to the sampled gas. 1.5 Precision, Accuracy, and Stability. 1.5.1 Precision. The estimated intralaboratory standard deviation of the method is 3 percent of the mean for gas samples analyzed in duplicate in the concentration range of 39 to 412 ppm. The interlaboratory precision has not been established. 1.5.2 Accuracy. The method contains no significant blases when compared to an NDIR analyzer calibrated with National Bureau of Standards (NBS) standards. 1.5.3 Stability. The individual components of the colorimetric reagent are stable for at least 1 month. The colorimetric reagent must be used within 2 days after preparation to avoid excessive blank correction. The samples in the Tedlar 1 bag should be stable for at least 1 week If the bags are leak-free. 2. Apparatus 21 Sampling. The sampling train is shown in Figure 10A-1, and component parts are discussed below: Mention of trade names or commercial products in this publication does not constitute the endorsement or recommendation for use by the Environmental Protection Agency. EC01JN92.180 2.1.1 Probe. Stainless steel, sheathed Pyrex glass, or equivalent. equipped with a glass wool plug to remove particulate matter. 2.1.2 Sample Conditioning System. Three Greenburg-Smith impingers connected in series with leak-free connections. 2.1.3 Pump. Leak-free pump with stainless steel and Teflon parts to transport sample at a flow rate of 300 ml/min to the flexible bag. 2.1.4 Surge Tank. Installed between the pump and the rate meter to eliminate the pulsation effect of the pump on the rate meter. 2.1.5 Rate Meter. Rotameter, or equivalent, to measure flow rate at 300 ml/min. Callbrate according to Section 5.2. 2.1.6 Flexible Bag. Tedlar, or equivalent. with a capacity of 10 liters and equipped with a sealing quick-connect plug. The bag must be leak-free according to Section 4.1. For protection, it is recommened that the bag be enclosed with a rigid container. 2.1.7 Valves. Stainless-steel needle valve to adjust flow rate, and stainless-steel threeway valve, or equivalent. 2.1.8 CO2 Analyzer. Method 3 or its approved alternative to measure CO₂ concentration to within 0.5 percent. 2.1.9 Volume Meter. Dry gas meter, callbrated and capable of measuring the sample volume under rotameter calibration conditions of 300 ml/min for 10 minutes. 2.1.10 Pressure Gauge. A water filled U-tube manometer. or equivalent, of about 28 cm (12 in.) to leak-check the flexible bag. 2.2 Analysis. 2.2.1 Spectrophotometer. Single- or doublebeam to measure absorbance at 425 and 600 nm. Slit width should not exceed 20 nm. 2.2.2 Spectrophotometer Cells. 1-cm pathlength. 2.2.3 Vacuum Gauge. U-tube mercury manometer, 1 meter (39 in.), with 1-mm divisions, or other gauge capable of measuring pressure to within 1 mm Hg. 2.2.4 Pump. Capable of evacuating the gas reaction bulb to a pressure equal to or less than 40 mm Hg absolute, equipped with coarse and fine flow control valves. 2.2.5 Barometer. Mercury. aneroid. or other barometer capable of measuring atmospheric pressure to within 1 mm Hg. 2.2.6 Reaction Bulbs. Pyrex glass. 100.ml with Teflon stopcock (Figure 10A-2), leakfree at 40 mm Hg, designed so that 10 ml of the colorimetric reagent can be added and removed easily and accurately. Commercially available gas sample bulbs such as Supelco Catalog No. 2-2161 may also be used. EC01JN92.181 2.2.7 Manifold. Stainless steel, with connections for three reaction bulbs and the appropriate connections for the manometer and sampling bag as shown in Figure 10A-3. 2.2.8 Pipets. Class A, 10-ml size. 2.2.9 Shaker Table. Reciprocating-stroke type such as Eberbach Corporation, Model 6015. A rocking arm or rotary-motion type shaker may also be used. The shaker must be large enough to accommodate at least six gas sample bulbs simultaneously. It may be necessary to construct a table top extension for most commercial shakers to provide sufficient space for the needed bulbs (Figure 10A-4). 2.2.10 Valve. Stainless steel shut-off valve. EC01JN92.182 2.2.11 Analytical Balance. Capable of accurately weighing to 0.1 mg. 3. Reagents Unless otherwise Indicated, all reagents shall conform to the specifications established by the Committee on Analytical Reagents of the American Chemical Society. where such specifications are available, otherwise. the best available grade shall be used. 3.1 Sampling. 3.1.1 Water. Deionized distilled, as described in Method 6. Section 3.1.1. 3.1.2 Alkaline Permanganate Solution, 0.25 M KMn0J1.5 M NaOH. Dissolve 40 g KMn0 4 and 60 g NaOH in water, and dilute to 1 liter. 3.2 Analysis. 3.2.1 Water. Same as in Section'3.1.1. 3.2.2 1 M Sodium Hydroxide (NaOH) Solution. Dissolve 40 g NaOH in approximately 900 ml of water, cool, and dilute to 1 liter. 3.2.3 0.1 M Silver Nitrate (AgNO₃) Solution. Dissolve 8.5 8 AgNO₃ In water, and dilute to 500 ml. 3.2.4 0.1 M Para-Sulfaminobenzoic Acid (p- SABA) Solution. Dissolve 10.0 g p-SABA in 0.1 M NaOH (prepared by diluting 50 ml of I M NaOH to 500 ml), and dilute to 500 ml with 0.1 M NaOH. EC01JN92.183 3.2.5 Colorimetric Solution. To a flask, add 100 ml of p-SABA solution and 100 ml of AgNO₃ solution. Mix, and add 50 ml of 1 M NaOH with shaking. The resultant solution should be clear and colorless. This solution is acceptable for use for a period of 2 days. 3.2.6 Standard Gas Mixtures. Traceable to NBS standards and containing between 50 and 1000 ppm CO in nitrogen. At least two concentrations are needed to span each callbration range used (Section 5.3). The calibration gases shall be certified by the manufacturer to be within 2 percent of the specified concentrations. 4. Procedure 4.1 Sample Bag Leak-checks. While a bag leak-check is required after bag use, it should also be done before the bag is used for sample collection. The bag should be leakchecked in the inflated and deflated condition according to the following procedures. Connect the hag to a water manometer, and pressurize the bag to 5 to 10 cm H2O (2 to 4 in. H₂O). Allow the bag to stand for 60 minutes. Any displacement in the water manometer Indicates a leak. Now. evacuate the bag with a leakless pump that is connected on the downstream side of a flow-indicating device such as a 0-to 100-ml/min rotameter or an impinger containing water. When the bag is completely evacuated. no flow should be evident if the bag is leak-free. 4.2 Sampling. Evacuate the Tedlar bag completely using a vacuum pump. Assemble the apparatus as shown in Figure 10A-1. Loosely pack glass wool in the tip of the probe. Place 400 ml of alkaline permanganate solution in the first two impingers and 250 ml in the third. Connect the pump to the third impinger, and follow this with the surge tank, rate meter, and three-way valve. Do not connect the Tedlar bag to the system at this time. Leak-check the sampling system by placing a vacuum gauge at or near the probe inlet, plugging the probe Inlet, opening the three-way valve, and pulling a vacuum of approximately 250 mm Hg on the system while observing the rate meter for flow. If flow is indicated on the rate meter, do not proceed further until the leak is found and corrected. Purge the system with sample gas by inserting the probe into the stack and drawing sample through the system at 300 ml/min +10 percent for 5 minutes. Connect the evacuated Tedlar bag to the system. record the starting time, and sample at a rate of 300 ml/min for 30 minutes, or until the Tedlar bag is nearly full. Record the sampling time, the barometric pressure, and the ambient temperature. Purge the system as described above immediately before each sample. The scrubbing solution is adequate for removing sulfur and nitrogen oxides from 50 Iiters of stack gas when the concentration of each is less than 1,000 ppm and the CO 2 concentration is less than 15 percent. Replace the scrubber solution after every fifth sample. 4.3 Carbon Dioxide Measurement. Measure the CO₂ content in the stack to the nearest 0.5 percent each time a CO sample is collected. A simultaneous grab sample analyzed by the Fyrite analyzer is acceptable. 4.4 Analysis. Assemble the system shown in Figure 10A-3, and record the information required in Table 10A-1 as it is obtained. Pipet 10.0 ml of the colorimetric reagent into each gas reaction bulb, and attach the bulbs to the system. Open the stopcocks to the reaction bulbs, but leave the valve to the Tedlar bag closed. Turn on the pump, fully open the coarse-adjust flow valve, and slowly open the fine-adjust valve until the pressure is reduced to at least 40 mm Hg. Now close the coarse adjust valve, and observe the manometer to be certain that the system is leak-free. Walt a minimum of 2 minutes. If the pressure has increased less than 1 mm, proceed as described below. If a leak is present. find and correct It before proceeding further. EC01JN92.184 Record the vacuum pressure (P ) to the nearest 1 mm Hg. and close the reaction bulb stopcocks. Open the Tedlar bag valve, and allow the system to come to atmospheric pressure. Close the bag valve, open the pump coarse adjust valve, and evacuate the system again. Repeat this fill/evacuation procedure at least twice to flush the manifold completely. Close the pump coarse adjust valve. open the Tedlar bag valve, and let the system fill to atmospheric pressure. Open the stopcocks to the reaction bulbs, and let the entire system come to atmospheric pressure. Close the bulb stopcocks, remove the bulbs, record the room temperature and barametric pressure (Phar. to nearest mm Hg). and place the bulbs on the shaker table with their main axis either parallel to or perpendicular to the plane of the table top. Purge the bulbfilling system with ambient air for several minutes between samples. Shake the samples for exactly 2 hours. Immediately after shaking, measure the absorbance (A) of each bulb sample at 425 nm If the concentration is less than or equal to 400 ppm CO or at 600 nm If the concentration Environmental Protection Agency, EPA is above 400 ppm. This may be accomplished with multiple bulb sets by sequentially collecting sets and adding to the shaker at staggered intervals, followed by sequentially removing sets from the shaker for absorbance measurement after the two-hour designated Intervals have elapsed. Use a small portion of the sample to rinse a spectrophotometer cell several times before taking an aliquot for analysis. If one cell is used to analyze multiple samples, rinse the cell several times between samples with water. Prepare and analyze standards and a reagent blank as described in Section 5.3. Use water as the reference. Reject the analysis if the blank absorbance is greater than 0.1. All conditions should be the same for analysis of samples and standards. Measure the absorbances as soon as possible after shaking is completed. Determine the CO concentration of each bag sample using the calibration curve for the appropriate concentration range as discussed in Section 5.3. 5. Calibration 5.1 Bulb Calibration. Weigh the empty bulb to the nearest 0.1 g. Fill the bulb to the stopcock with water, and again weigh to the nearest 0.1 g. Subtract the tare weight, and calculate the volume in liters to three significant figures using the density of water (at the measurement temperature). Record the volume on the bulb; alternatively. mark an identification number on the bulb, and record the volume in a notebook. 5.2 Rate Meter Calibration. Assemble the system as shown in Figure 10A-1 (the impingers may be removed). and attach a volume meter to the probe inlet. Set the rotameter at 300 ml/min, record the volume meter reading, start the pump, and pull gas through the system for 10 minutes. Record the final volume meter reading. Repeat the procedure and average the results to determine the volume of gas that passed through the system. 5.3 Spectrophotometer Calibration Curve. The calibration curve is established by taking at least two sets of three bulbs of known CO collected from Tedlar bags through the analysis procedure. Reject the standard set where any of the individual bulb absorbances differ from the set mean by more than 10 percent. Collect the standards as described in