Document g3qd0NxMvEe22668G72RG8q3

375-- Fodoral RogiEtof / Vc a. No. 161 / Thursday, August 16, 196.' Rules and Regulations could ba either rimilly inspected, or filled altcmutive to the pressure source deacrilwd with water to delect any liquid leakage.) above. Likewise, the draining of water out of 5.1.S Attach the teet cap to the end of the vapor recovery hose. 5.1.4 Connect the presaure-vacuum lupply hoae and the preeaure-vacuum relief valve to the shut-off valve. Attach a manometer to the pressure tap. 5.1.5 Connect compartments of the tank internally to each other if poeeible. If not possible, each compartment muat be tealed separately, aa if it were an individual delivery tank. 5.2 Pressure test. the bottom of a delivery tank may be substituted Tor the vacuum source. Note that some of the specific step-by-step procedures in the method must be eltered slightly to accommodate these different pressure and vacuum sources. 6.2 Techniques other than specified above may be used for purging and pressurizing a delivery lank, if prior approval ia obtained from the Administrator. Such approval will be based upon demonstrated equivalency with the above method. 5.2.1 Connect the pressure source to the |FR Due SS-Z2WI Filed S-17 -Sk sat ,m| pressure-vacuum supply hose. 5.2.2 Open the shut-off valve in the vapor smjjmq coot ssae se-n recovery hose cap. Applying air pressure slowly, pressurize the tank to P,, the initial pressure specified in the regulation. 40 CFR Part 60 5.2.3 Close the shut-off valve and allow [AD-FRL-2241-6a] Xthe pressure in the tank to stabilize, adjusting the pressure if necessary to maintain dditton of Reference Method 21 to pressure of P,. When the pressure stabilizes, record the time and initial pressure. Appmdli A 5.2.4 At the end of t minutes, record the AGENCY: Environmental Protection time and final pressure. Agency (EPA). 5.Z5 Repeat steps 5.2.2 through 5.2.4 until the change in pressure for two consecutive ACTION: Final rule. runs agrees within 12.5 mm H0. Calculate the arithmetic average of Ihe two results. 5.2.8 Compere (he average measured change in pressure to the allowable pressure change, Ap, as specified in the regulation. If Ihe delivery tank does not satisfy the vapor SUMMARY: This action establishes a new reference method lo be added to Appendix A of 40 CFR Part 80. standards of performance for new stationary sources. Reference Method 21 lightness criterion specified in Ihe regulauon, will be used to determine volatile repair the sources of leakage, and repeat the organic compound (VOC) leaks from pressure test until the criterion is met. process equipment such as valves, 5.2.7 Disconnect the pressure source from the pressure-vacuum supply hose, and slowly open the shut-off valve to bring the tank to atmospheric pressure. 5 3 Vacuum test. 5.3.1 Connect the vacuum source to the flanges and other connections, pump and compressor seals, pressure relief devices, process drains, open-ended valves, pump and compressor seal system degassing vents, accumulator pressure-vacuum supply hose. vessel vents, agitator seals, and accesa 5.3 2 Open the shut-ofT valve in the vapor door seals. This reference method will recovery hose cap. Slowly evacuate the tank to V,, the initial vacuum specified in the regulation. 5.3.3 Close the stiui-off valve and allow the pressure in the lank to stabilise, adjusting the pressure if necessary to maintain a be used in several air pollution regulations for the limitation of fugitive VOC emissions which are being developed for proposal and promulgation. vacuum of V,. When the pressure stabilizes, EFFECTIVE GATE: August 18, 1963. record the time and initial vacuum. 5.3.4 At the and of I minutes, record the tune and final vacuum. 5.3.5 Repeat steps 5-3.2 through 5.3.4 until the change in vacuum for two consecutive rune egress within Q1JL5 mm HaO. Calculate AOONEESEA: Docket. A docket, number A-79-32, containing information considered by EPA in development of standards of performance for fugitive emission sources in the synthetic the arithmetic average of the two results. organic chemical manufacturing 5.3.8 Compare this average measured industry, and which also contains change in vacuum to the allowable vacuum information considered in development change, Ap, as specified in the regulation. U the delivery tank docs not satisfy the vapor tightness criterion specified in the regulation, repair the sources of leakage, and repeal the vacuum test until the criterion ia met. 5.37 Disconnect the vacuum source from the pressure-vacuum aupply hose, and slowly of the promulgated reference method, is available for public inspection and copying between 6:00 a.m. and 4:00 p.m., Monday through Friday, at EPA's Central Docket Section (A-130). West Tower Lobby. Gallery 1. 401, M Street, open the shut-off valve to bring the tank to SW.. Washington. D C. 2046a A atmospheric pressure. reasonable fee may be charged for 5.4 Poet-test clean-up. Disconnect all test equipment and return the delivery tank to its pretest condition. 6 Alternative Procedures. 8.1 The pumping at water into the bottom copying. FOR FURTHER INFORMATION CONTACT: Mr. Winton Kelly. Emission Measurement Branch. Emission of a delivery teak la aa acceptable Standards and Engineering Division (MD-13), U.S. Environmental Protection Agency. Research Triangle Park. North Carolina 27711, telephone (919) 5415543. SUPPLEMENTARY INFORMATION: Summary of the Reference Method Reference Method 21, "Determination of Volatile Organic Compound Leaks" is used to detect VOC leaks from individual sources of fugitive emissions. This procedure is used lo identify and classify leaks only, and is not to be used as a direct measure of mass emission rates from individual sources. A portable instrument is used to measure the local organics concentration at the surface of a potential leak source. If a meter reading equal to or greater than a limit specified in an applicable regulation ia obtained, a VOC emission (leak) exists. The procedure can also be used to confirm that "no detectable emissions" are present. If the measured difference between the local ambient concentration and the concentration present at the surface of the potential leak source is less than a concentration specified in an applicable regulation, then there are no detectable emissions. Background On January 5,1961. as an appendix to the proposed standards of performance for fugitive emission sources in the synthetic organic chemical manufacturing industry. EPA proposed Reference Method 21. This method would normally be promulgated with those standards. However, the method is being promulgated earlier because several additional regulations are baing developed for promulgation in the near future that specify thet Reference Method 21 be used. This early promulgation will ensure that the reference procedure will be promulgated prior to being specified in promulgated standards of performance. Under Executive Order 12291. EPA must judge whether a regulation ia "major" and, therefore, subject to the requirement of a regulatory impact analysis. This regulation is not major because it will not have an annual effect on the economy of $100 million or more: it will not result in a major increase in costs or prices: and there will be no significant adverse effects on competition, employment, investment, productivity, innovation, or on the ability of U.S.-based enterprise to compete with foreign-based enterprises in domestic or export marketB. Pursuant to tha provisions of 5 U.S.C. 606(b). 1 hereby certify that tha attached rule will not have a significant economic DTH 000029646 Federal Register / V^1 48, No. 161 / Thursday, August 18. 198" I Rules and Regulations 37599 impact on a substantial number of small entities. Pufattc Participation During the development of the test method, trade and professional associations and individual companies supplied comments on the methods. After proposal on January 5,1981. comments were received from various sources. A public hearing was held on March 3,1981. to receive additional formal comments. The formal comment period was extended from April 8. 1981. to July 31.1981. Public Comments and Changes Made to the Proposed Reference Method Numerous comments were received in response to proposal of the standards of performance for fugitive emissions from synthetic organic chemical industry. Most of the comments concerning the test method were specifically related to the selection of the definition of a leak, and not to the procedure alone. These comments have been carefully considered and. where determined to be appropriate, changes have been made in the proposed test method. A detailed discussion of the comments and full responses will be included in Docket No. A-79-32. The following discussion summarizes the changes made to the reference method based on additional review and in response to public comment. The promulgated reference method has been reorganized to improve the clarity of the description of the procedures. A "Definitions" section has been added to place all the definitions in one section. A change in the requirements for instrument performance evaluation was also made to improve the quality control of the procedure. Instead of requiring a calibration precision test consisting of nine repetitions at 8-month intervals, the new requirements specify a test consisting of three repetitions at 3month intervals. This change will provide a quality control result every quarter and will require leas effort. The definition of "no detectable emissions'' has been changed to be consistent with the instrument specification of scale readability. The proposed procedure defined "no detectable emissions" as 2 percent of the leak definition concentration, with a minimum scale readability of 5 percent of the leak definition. The definition of no detectable emissions" has been changed to correspond to the minimum readability specification and will be specified in applicable regulations. Several commenters noted that the instruments used during screening studies responded differently for different chemicals. One commenter stated that the actual response factor was poorly related to the theoretical response factor and cited inconsistent responses for nonane and decane, as well us no response for some chemicals, to support his claims. Another commenter suggested that the leak concentration for the standards should vary according to the process unit since a wide variability (0 to 571) in response factors has been determined for ihe industry And. another commenter stated that aromatic compounds such us benzene, toluene, and xylene demonstrate a nonlinear response close to 10.000 ppinv. In response to these comments. Reference Method 21 gives specifications for ihe instrument to be used in monitoring fugitive VOC emission sources. The technique is intended to classify leaks only, not to provide a rigorous analytical concentration or mass emission rate of VOC. A specific statement has been added to Method 21 to clarify the intention to classify leaks only. The variation ui response factor due to compound or instrument is not expected to affect significantly the number of leaks determined through screening because screening values are usually much greater than the leak definition for leaks and much less than the leak definition for nonleaks. Two industry commenters concur with EPA in this position. However, to remove some of the wide variability, a definition, specification, and test procedure for response factors have been added to Method 21. This specification will assure that the analyzer used will respond to the compounds to be measured. Another commenter suggested that the gas specification section be amended to include a turnover of calibration gas standards every 3 months since calibration gases can deteriorate significantly over time. A provision has been added to the promulgated Reference Method 21 to require a shelf- life specification on calibration gases and procedures to follow to ensure that calibration gas concentrations are accurate. Two comments concerned the instrumentation requirements of Reference Method 21. The commenter stated that only two instruments on the market today could be considered, and neither one would meet the specifications of the reference method entirely: the first instrument fails the calibration accuracy, and the section instrument does not meet the response time requirement. In response, although there are only two instruments which have been used to any great extent, the technical literature and product information suggest that there are others which could be used for detecting leaks. The specifications included in the proposed reference method are achievaLle based on performance during EPA studies. One comment letter expressed concern that no provision was made for the use of new instruments or calibration procedures which would provide equivalent or mure accurate results. They asked that equivalency provisions tie added for lest methods and procedures. In response. Reference Method 21 gives specifications for the monitoring instrument that are general enough so us nol to preclude new analytical developments. In addition, the Ceneral Provisions (40 CFR Part 60, Subpart A) allow for equivalent methods and procedures to be used for performance testing and monitoring when the results of the equivalent method have been demonstrated to be at least as accurate as results obtained by the required methods. One commenter suggested that use of a windscreen upwind of the component being screened would prevent meteorological effects on the instrument readings. During EPA studies, the selection of a measurement location at the surface of the source was made to minimize meteorological effucts. During the data collection efforts, no further provisions were found necessary to obtain repeatable screening values. Therefore, all of the field data were collected without a windscreen. In view of these facts, it seems unnecessary to require that a windscreen be used. An alternative screening procedure has been added for those sources that can be tested with a soap solution. These sources are restricted to those with non-moving seals, moderate surface temperatures, without large openings to atmosphere, and without evidence of liquid leakage. The soap solution is sprayed on all applicable sources and the potential leak sites are observed to determine if bubbles are formed. If no bubbles are formed, then no detectable emissions or leaks exist, if any bubbles are formed, then the instrument measurement techniques must be used to determine if a leak exists, or if no detectable emissions exist, as applicable. The alternative soap solution procedure does not apply to pump seals, sources with surface temperatures greater than the boiling point or less than the freezing point of the soap solution, sources such as open-ended lines or valves, pressure relief value DTH O O O O 2 a S i 37800 Federal Register / Vol. 48, ions horns, vents with large openings to atmosphere, and any source where liquid leakage is present. The instrument technique in the method must be used for these sources. The alternative of establishing a soap scoring leak definition equivalent to a concentration-based leak definition is not included in the method and is not recommended for inclusion in an applicable regulation because of the difficulty of calibrating and normalizing a scoring technique based on bubble formation rates. A scoring technique would be based on estimated ranges of volumetric leak rates. These estimates depend on the bubble size and formation rute. which are subjective judgments of an observer. These subjective judgments could only be calibrated or normalized by requiring that the observers correctly identify and score a standard series of test bubbles. It has been reported Ihut truinud observers can correctly and repeHtably classify ranges of volumetric leak rates. However, because soap scoring requires subjective observations and since an objective concentration measurement procedure is available, a soap scoring equivalent leak definition is not recommended for the applicable regulation. The alternate procedure that has been included will allow more rapid identification of potential leaks for more rigorous instrumental concentration measurement. Miscellaneous This final rulemaking is issued under the authority of Sections 111, 114, and 301(a) of the Clean Air Act. as amended [42 U.S.C. 7411, 7414, and 7891(a)). List of Subjects in 40 CFR Part 60 Air pollution control. Aluminum, Ammonium sulfate plants. Asphalt. Cement industry, Coal copper. Electric power plants, Class and glass products, Grains, Intergovernmental relations. Iron, Lead, Metals, Metallic minerals. Motor vehicles, Nitric acid plants, Paper and paper products industry, Petroleum, Phosphate. Sewage disposal, Steel. Sulfuric acid plants. Waste treatment and disposal. Zinc, Tires. Dated: August 4, 1S83. William D. Ruckelshaus, Administrator. Appendix A of 40 CFR Part 80 is amended by adding Reference Method 21 as follows. Appendix A--Reference Methods ***** Method 21. Determination of Volatile Organic Compounds I talri 1. Applicability and Principle. 1.1 Applicability. This method applies to the determination of volatile organic compound (VOC) leaks from process equipment. These sources include, but are not limited to. valves, flanges and other connections, pumps and compressors, pressure relief devices, process drums, openended valves, pump and compressor seal system degassing vents, accumulator vessel vents, agitator seals, and access door seals. 1.2 Principle. A portable instrument is used to detect VOC leaks from individual sources. The instrument detector type is not specified, but it must meet the specifications and performance criteria contained in Section 3. A leak definition concentration bused on a reference compound is specified in each applicable regulation. This procedure is ' intended to locate and classify leaks only, and is mil lo be used ss a direct measure of muss emission rules from individual sources. 2. Definitions. 2.1 Leak Definition Concentration. The local VOC i.oiicenlrution ul the surface of a leak source tlial liidicules (hut a VOC emission |leuk) is present. Thu leak definition is ui! lusli uiiunil meler reading bused on u reference compound. 2.2 Reference Compound. The VOC species selected us an inslrumenl calibration basis for specification of the leak definition concentration. (For example: If a leak definition concentration is 10,000 ppmv as methane, then any source emission that results in a local concentration that yields a meter reading of 10,000 on an instrument calibrated with methune would be classified as a leak. In this example, the leak definition is 10.000 ppmv, and the reference compound is methane.) 2.3 Calibration Gas. The VOC compound used to adjust the instrument meter reading to a known value. The calibration gus is usually the reference compound at a concentration approximately equal to the leak definition concentration. 2.4 No Detectable Emission. The local VOC concentration at the surface of a leak source that indicates that a VOC emission (leak) is not present. Since background VOC concentrations may exist, and to account for instrument drift and imperfect reproducibility, a difference between the source surface concentration and the local ambient concentration is determined. A difference based on meter readings uf less than a concentration corresponding tu the minimum readability specification indicates that a VOC emission (leak) is not present. (For example, if the leak definition in u regulation is 10.000 ppmv, then the allowable increase in surface conceniralion versus local ambient concentration would be SIX) ppmv baaed on the instrument meter readings.) 2.5 Response Factor. The ratio of the known conceniralion of a VOC compound to the observed meter reading when meusured using an instrument calibrated with the reference compound specified in the application regulation. 2.6 Calibration Precision. The degree of agreement between measurements of the same known value, expressed as ihe relative percentage of the average difference between the meter readings and the known concentration to the known concentration. 2.7 Response Time. The time interval from a step change in VOC conceniralion al ihe input of ihe sampling system to ihe lime al which SO percent of the corresponding final value is reached as displayed on (he instrument readout meter. 3. Apparatus. 3.1 Monitoring instrument. 3.1.1 Speci ficutions. a. The VOC instrument detector shall respond lo the compounds being processed Detector types which may meet Ihis requirement include, but are not limited lo. catalytic oxidation, flame ionization, infrared absorption, and pholoiomzation. b. The instrument shall be capable of measuring Ihe leak definition conceniralion specified in Ihe regulation. c. The scale of the inslrumenl meler shall be readable lo 5 percent of Ihe specified leak definition concentration. d. The inslrumenl shall be equipped wnh a pump so Ihut u continuous sample is provided lo Ihe detector I he noimnul sample flow rale ahull be W lo 3 liters per miruitu e The liialniimml shall be lulrinsu ally a.,!,, fur operubon in explosive atmospheres as defined by the applicable U.S.A. standards (e g.. National Kleclrioal Code by (he National Fire Prevention Association). 3.1.2 Performance Criteria a. The instrument response factors for the individal compounds lo be meusured must be less lhan 10. b. The inslrumenl response time must be equal to or less than 30 seconds. The response time must lie determined for the instrument configuration to be used duru , testing. c. The calibration precision must be equal lo or less than 10 percenl of the calibration gas value. d. Thu evaluation procedure for each parameter is given in Section 4.4. 3.1.3 Performance Evaluation Requirements. a. A response factor must be determined for each compound that is to be meusured. either by testing or from reference sources. The response factor tests are required before placing the analyzer inlo service, but do not have to be repeated as subsequent intervals. b. The calibration precision letl must be completed prior lo placing Ihe analyzer into service, and at subsequent 3-month intervals or ul the next use whichever is leler. c. The response lime test is required prior to placing Ihe instrument into service. If a modification lu ihe sample pumping system or flow configuration is made that would change the response time, a new lest ts required prior lo further use. 3.2 Calibration Cases. The monitoring instrument is calibrated in terms of parts per million by volume (ppmv) of the reference compound specified in the applicable regulation. The calibration gases required for monitoring and instrument performance evaluation are a zero gas (air, less than 10 ppmv VOC) and a calibration gas in air mixture approximately equal to the leak definition specified in the regulation. If cylinder calibration as mixture are used, they must be analyzed and certified by Ihe manufacturer to be within 2 percent DTH 000029B48 Federal Register / Vol. 48, No. 161 / Thursday, August 18, 1983 / Rules and Regulations 37601 accuracy, and a ahelf life must be apecified. Cylinder alandurda mual be either reanalyzed or replaced at the end of the apecified ahelf life. Alternately, calibration gaaea may be prepared by the user according to any accepted gaseous standards preparation procedure (hat will yield a mixture accurate to within 2 percent. Prepared standards must be replaced each day of use unless it can be demonstrated that degradation does not occur during storage. Calibrations may be performed using a compound other than the reference compound if a conversion factor is delermined for that alternative compound so thal the resulting meter readings during source surveys can be converted to reference compound results. 4 Procedures. 4.1 Pretest Preparations Perform the instrument evaluation procedures given in Section 4.4 if the evaluation requirements of Section 3.1.3 have not been met. 4.2 Calibration Procedures. Assemble and slart up the VOC analyzer according to the manufacturer s inslrui.lions. After the appropriate warmup period uud zero Internal calibration procedure, introduce the calibration gas into the instrument sample probe. Adjust the instrument meter readout to correspond tu (he calibration gus value Note.--If the meter readout cannot be adjusted to the proper value, a malfunction of the analyzer is indicated and corrective actions are necessary befure use. 4.3 Individual Source Surveys. 4.3.1 Type I--Leak Definition Based on Concentration. Place the probe inlet at the surface of the component interface where leakage could occur. Move the probe along the interface periphery while observing the instrument readout If an increased meter reading is observed, slowly sample the interface where leakage is indicated until the maximum meter reading is obtained. Leave ihe probe inlet at this maximum reading locution for approximately two times the instrument response time. If the maximum observed meter reading is greater than the leak definition in the applicable regulation, record and report the results as specified in Ihe regulation reporting requirements. Examples of the application of thia general technique to specific equipment types are: a. Valve*--'The moat common source of leaks from valves is at the seal between the stem and housing. Place the probe at the interface where the stem exist* the packing gland and sample the stem circumference. Also, place the probe at the interface of the packing gland take-up flange seat and sample the periphery, in addition, survey valve housing* of multipart assembly at the surface of all interface* where leak could occur. b. Flanges and Other Connection*--For welded flanges, place the probe at the outer edge of the flange-gasket interface and sample the circumference of the flange. Sample other types of nonpermanent joint* 'such as threaded connections) with a similar traverse. c. Pumps and Compressor*--Conduct a circumferential traverse at the outer surface of the pump or compressor shaft and seal interface. If the source ia a rotating shaft position the probe Inlet within 1 cm of Ihe shaft-aeal interface for the survey. If the housing configuration prevents a cumplele traverse of the shaft periphery, sample all accessible portions. Sample all other juints on the pump or compressor housing where leakage could occur d. Pressure Relief Devices--The configuration of most pressure relief devices prevents sampling at Ihe sealing seat interface. For those devices equipped with un enclosed extension, or horn, place the probe inlet at approximately the center of the exhaust area to the atmosphere. e. ihocess Drams--For open drains, place the probe inlet ut approximately Ihe center of the area open lo the atmosphere. For covered drums, place the probe at the surface of Ihe cover inlerfai e and conduct a peripheral truverse. f Open-Fruied Lines ur Valves--Place Ihe probe inlet at approximately the center of the opening to the atmosphere. g. Seal System Degassing Vents und Accumulator Vents--Place Ihe probe inlet at appioxmialely the center of the opcooig to the iitinosphei e li Access Door Seals - Place the prohe mlel ut the surface of tile door seal inleilace and cunduct a peripheral truverse. 4 3 2 Type II - "No Delertnble Emission". Determine the local unihlciil com.call alien around the source by moving the probe mlel randomly upwind and downwind at a distance of one to two meters from the source. If an interference exists with llns determination due lo a nearby emission or leak, the local ambient concentration may be determined at distances closer to the source, but in nu case shall the distance be less than 25 centimeters. Then move Ihe probe inlet lo the surface of the source and determine the concentration described in 4.3.1. The difference between ihese concentrations determines whether there are no detectable emissions. Record and icport Ihe results as specified by the regulation. For those cases where the regulation requires a specific device installation, or that specified vents be ducted or piped to a control device. Ihe existence of these conditions shall be visually confirmed. When Ihe regulation also requires that no detectable emissions exist, visual observations and sampling surveys are required. Examples of this technique are: (a) Pump or Compressor Seuls--If applicable, determine the type of shaft seal. Preform a survey of the local area ambient VOC concentration and determine if detectuble emissions exist as described above. (b) Seal System Degassing Vents. Accumulator Vessel Vents. Pressure Relief Devices--If applicable, observe whether or not the applicable ducting or piping exists. Also, determine if any sources exist in the ducting or piping where emissions could occur prior to the control device. If the required ducting or piping exiate and lliere are no sources where the emissions could be vented to the atmosphere prior to the control device, then it ie presumed that no detectable emiesion* are present. If there are sources in the ducting or piping where emission* could ba vented or source* where leeks could occur, the sampling surveys described in Ibis paragraph shall be used to determine if detectable emissions exist. 4.3.3 Alternative Screening Procedure A screening procedure based on the formation of bubbles in a soap solution that is sprayed on a potential leak aource may be used for those sourcee that do not have continuously moving purls, ihul do not have surface temperatures greater than Ihe boiling point or less than the freezing point of the soup solution, that do not have open ureas to the atmosphere (hut the soap solution cunnut bridge, or that do not exhibit evidence of liquid leakage. Sources that have these conditions present must be surveyed using Ihe instrument techniques of 4.3.1 or 4.3 2 Spray u soup soliilion over all polenliui leak sources. The soap solulum may be a commercially available leak'deleclion solution or muy be prepared using concentrated detergent and water A pressure sprayer or a squeeze Imttle muy lie uhiuI to dispense I lie solution. Observe the (mUmtiiil leak silos In iletoruuuc if any bubbles me formed. If no bobbins urn observed. Ihe source Is piosiimed In lluvn no ilelm table emissions ur Icuks us applicable. II any bubbles are observed. Ihe instrument loi.liiiiqiies of 4 3.1 or 4 3 2 shall bn used In determine if a leak exists, ur il tfie source has detectable emissions, as applicable. 4.4 Instrument Evaluation Procedures At ihe beginning of ihe instrument performance evaluation test, assemble und start up the instrument according to the manufacturer s instructions (or recommended warmup period and preliminary adjustments. 4.4.1 Response Factor. Calibrate ihe instrument with the reference compound as specified in the applicable regulation. For each organic species dial is to be measured during individual source surveys, obtain ur prepare a known standard in air at a concentration of approximately (Ml percent of Ihe applicable leak definition unless limited by volulility or explosiVity In Ihese cases, prepare a standard ut 90 percent of the saturation concentration, or 70 percent of ihe lower explosive bind, respectively Introduce (his mixture to the analyzer and record the observed meter reading. Introduce zero air until a stable reading ia obtained. Make a total of three measurements by alternating between the known mixture and zero air. Calculate the response factor for each repetition and the average response factor. Alternatively, if response factor* have been published for die compounds of interest for the instrument or detector type, the response factor determination ia not required, and existing results may be referenced. Examples of published response factors for flame ionization and catalytic oxidation detectors are included in Section 5. 4.4.2 Calibration Precision. Make a total of three measurements by alternately using zero gas and the specified calibration gat. Record the meter readings. Calculate the average algebraic difference between Ihe meter readings and the known value. Divide this average difference by the known calibration value and mutiply by 100 to express the resulting calibration precision as a percentage. DTH 000029849 37602 Federal Register / Vo i. No. 161 / Thursday. Augual 18, 198: Rules and Regulations 4.4.3 Response Time. Introduce zero gas into the instrument sample probe. When the meter reading has stabilized, switch quickly to the specified calibration gas. Measure the time from switching to when 90 percent of the final stable reading is attained. Perform this test sequence three times and record the results. Calculate the average response time 5. Bibliography. 5.1 DuBose. DA.. and G.E. Harris. Response Factors of VOC Analyzers at a Meter Reading of 10.000 ppmv for Selected Organic Compounds. U.S. Environmental Protection Agency. Research Triungle Park, N.C. Publication No. EPA 600/2-81-051. September 1981. 5.2 Brown. G.E. el al Response Factors of VOC Analyzers Calibrated with Methane for Selected Organic Compounds. U.S. Environmental Protection Agency, Research Triangle Park. N.C Publication No. EPA 600/ 2-81-022. May 1981. 5.3 DuBose. D.A., et a/. Response of Portable VOC Analyzers to Chemical Mixtures. U.S. Environmental Protection Agency, Research Triangle Park, N.C. Publication No. EPA 000/2-81-110. September 1981. |FK Due 8S-224SV Filed S-17-S3; a 45 m| BUXUM COM SSSO S S DTH 000029