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Enforcement Section
SOP for Using Portable Analyzers in Performance Tests

(Version 1.6 – 04/25/97-RS)

If the Air Quality Bureau (Bureau) approves the use of a portable analyzer to measure pollutant concentrations in stack gases, the following is required:

Unless otherwise approved by the Bureau, the Portable Analyzer must be certified the first time it is used. The certification requires running a field test in parallel with an emissions testing firm, utilizing the Reference Method procedures of 40 CFR 60 Appendix A. Following the test, a report must be submitted conforming to the Bureau’s SOP for Stack Test Reports. The portable analyzer test report must include a table comparing the pollutant concentrations, mass emission rates, volumetric stack flow, stack gas moisture content, stack gas oxygen content, and stack temperature for both sets of measurements. The percent error from the Reference Method results must be calculated for each run.

The tester must submit a test protocol for the Bureau’s approval.  The protocol must comply with the Bureau’s SOP  for Stack Test Protocols.  The protocol must include all pertinent information regarding the portable analyzer. For quarterly testing, a protocol will be required the first time a test is performed.  If there are no changes in procedure for subsequent testing, a new protocol will not be required.  Portable Analyzers shall be used to determine concentrations for CO, NOx, VOC’s, SO2, and O2 only.  The analyzer is not to be used during any test required by federal New Source Performance Standards ("NSPS").

Sample Conditioning:

A.    The portable analyzer shall be calibrated and maintained in accordancewith manufacturer’s specifications. If moisture removal is not required,the manufacturer’s data which demonstrates this must be included with the protocol.

B.    If the response time as defined by section 6.B below exceeds 3 minutes, a small portable pump in series with the analyzer may be used to reduce the response time. Care must be taken to prevent the auxiliary pump from contaminating the sample with oil or dirt. If an auxiliary pump is used, the pump must be in place during any calibration procedures described in section 7 below.

C.    If moisture removal is required:

            1.    The stack gas shall be passed through a moisture removal system which conforms to 40 CFR 60,  Appendix A, Reference Method 6C (Method 6C), section 5.1.5. An equivalent system that will  continually remove water vapor, without removing a significant amount of pollutants to be measured,  maybe approved by the Bureau.

                      2.   The sample line which transports the stack gas to the moisture removal system shall be sufficiently  heated to prevent condensation.

Analyzer Range/Sensitivity:

           A.    The analyzer’s range and sensitivity shall conform to Method 6c, section 2.1 and 2.2.

           B.    The system response time is defined in Method 6C, Section 6.4.1. The results of the response time test  must be included in the final test report.

Analyzer Calibration:

           A.    For CO, NOx, and SO2 measurements, the Portable Analyzer must meet the performance specifications of Method 6c, Section 4, modified as follows:

                       1.    Analyzer calibration error: less that ± 4% of the span for the zero, mid-range, and high-range calibration gases. Use the procedure of Method 6C, Section 6.3.

                       2.    Sampling system bias: less that ± 10% of the span for the zero, mid-range, and high-range calibration gases.  Use the procedure of Method 6C, Section 6.4.

                       3.    Zero drift: less than ± 6% of the span over the period of each run. Use the procedure of Method 6C, Section 7.4.

                       4.    Calibration drift: less than ± 6% of the span over the period of each run. Use the procedure of Method 6C, Section 7.4.

            B.    For engines fueled by natural gas, the analyzer need not be calibrated for NO2 provided that in all emission calculations the tester agrees to use an NO2 concentration of either 10% of the measured NO concentration, or the measured NO2 concentration, whichever is greater.

            C.    Three calibration gases, as specified in Method 6C, Sections 5.3.1 through 5.3.2, shall be used. Ambient air may be used as the zero gas.

            D.    The calibration gases for NO, CO, SO2, O2, and VOC shall be certified to ± 3% accuracy. All calibration gases shall be used from their original containers.

            E.    If excess combustion air is determined using the oxygen sensor of the Portable Analyzer, the analyzer’s oxygen sensor must meet the calibration specifications of Conditions 7.A.1 through 7.A.4 above.

Stack Gas Volumetric Flow and Moisture Content:

            The stack gas volumetric flow and moisture content may be determined using 40 CFR 60 Appendix A, Methods 1-4, or by knowledge of fuel gas composition and combustion stoichiometry. Combustion stoichiometry may be used to determine stack gas flow provided the following requirements are meet:

            A.    A certified analysis of the fuel gas must be conducted within ± 24 hours of the test. If the company can demonstrate that the fuel gas is of pipeline quality, and the fuel BTU content does not fluctuate, then no analysis is necessary. The analysis or documentation regarding the quality of the fuel must be included with the final test report.

            B.    The fuel flow meter is calibrated before the test and the calibration data included in the final test report

           Sampling Requirements:

                 A.    The sample shall be drawn from location in the stack as required by 40 CFR 60, Methods 1-4.

                 B.    The test shall consist of a minimum of three runs.

                 C.    Each run shall consist of a total sampling time of at least twice the amount of time it takes for the analyzer to stabilize, but no less than 20 minutes. The Bureau may require a specific sampling time in some cases.

The purpose of this SOP is not to replace the reference methods of 40 CFR 60 Appendix A, but rather to facilitate the measurement of emissions from sources that require periodic emission tests as part of their monitoring schedules.

Performance tests using a portable analyzer will not be accepted, unless all of the above conditions are met, and a protocol is approved by the Bureau prior to testing.

The Bureau reserves the right to withdraw or modify this SOP without advance notice.

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