Multi-Sector Air Pollutants Regulations — 84
Reading for CO and NO interference responses 84 (1) When a reading of an electrochemical cell’s response to a span gas for NO or NO 2 is taken under subsection 83 (1), a reading must also be taken — for the purpose of determining the CO and NO interference responses — of the response of the following other cells of the analyzer to that span gas: (a) for a span gas for NO, the CO cell; and (b) for a span gas for NO 2 , the CO and NO cells. CO interference response (2) The CO interference response — namely, the response of the CO cell to the presence of NO and NO 2 in the introduced span gas — is the percentage determined by the formula [(R CO−NO /C NOG × C NOS /C COS ) + (R CO−NO2 /C NO2G × C NO2S /C COS )] × 100 where R CO−NO is the CO response to span gas for NO, expressed in ppm of CO; C NOG is the certified concentration of NO in the span gas for NO, expressed in ppm of NO; C NOS is the concentration of NO in the exhaust gas of the engine, as determined in accordance with section 89 for the most recent emissions check that was conducted by means of the analyzer referred to in subsection (1), expressed in ppm of NO; C COS is the concentration of CO in the exhaust gas of the engine, as determined in accordance with section 89 for that most recent emissions check, expressed in ppm of CO; R CO−NO2 is the CO response to span gas for NO 2 , expressed in ppm of CO; C NO2G is the certified concentration of NO 2 in the span gas for NO 2 , expressed in ppm of NO 2 ; and C NO2S is the concentration of NO 2 in the exhaust gas of the engine, as determined in accordance with section 89 for that most recent emissions check, expressed in ppm of NO 2 . NO interference response (3) The NO interference response — namely, the response of the NO cell to the presence of NO 2 in the introduced span gas — is the percentage determined by the formula R NO−NO2 /C NO2G × C NO2S /C NOxS × 100 where R NO−NO2 is the NO response to span gas for NO 2 , expressed in ppm of NO; C NO2G is the certified concentration of NO 2 in the span gas for NO 2 , expressed in ppm of NO 2 ; C NO2S is the concentration of NO 2 in the exhaust gas of the engine, as determined in accordance with section 89 for the most recent emissions check that was conducted by means of the analyzer referred to in subsection (1), expressed in ppm of NO 2 ; and C NOxS is the concentration of NO x in the exhaust gas of the engine, as determined in accordance with section 89 for that most recent emissions check, expressed in ppm of NO x . No prior emissions check (4) If there is no prior emissions check conducted by means of the analyzer referred to in subsection (1), (a) the value of C NOS , C COS and C NO2S referred to in subsection (2) or (3) is the certified concentration of NO, CO and NO 2 , respectively, in the span gas for that gas, expressed in ppm of that gas; and (b) the value of C NOxS referred to in subsection (3) is the total of the certified concentrations of NO and NO 2 in the span gas for NO and NO 2 , respectively, expressed in ppm of NO x . Interference response ≤ 5% (5) The CO interference response and the NO interference response must each be at most 5%.