Multi-Sector Air Pollutants Regulations — 83
Sequence of calibration error checks 83 (1) A sequence of calibration error checks consists of two calibration error checks on each of the electrochemical cells of an analyzer, one involving the introduction of a zero gas and the other involving the introduction of a span gas. Calibration error checks (2) A calibration error check on an electrochemical cell of an analyzer is conducted by introducing into the analyzer, at a constant flow rate, a calibration gas — namely, a zero gas or a span gas — for each of the gases referred to in subsection (3) to which that cell is designed to respond in order to determine the difference between (a) the concentration of that gas in that calibration gas, as indicated by the reading of that cell’s response to it taken after the stabilization period for the calibration error check for that cell, and (b) the certified concentration of that gas in that calibration gas. Calibration gases (3) The zero gas and the span gas for the following gases to which a cell is designed to respond are (a) for O 2 , (i) a zero gas that consists of (A) O 2 in nitrogen, with a certified concentration of O 2 of less than 0.25% of the concentration of O 2 in its corresponding span gas, (B) CO in nitrogen, or in air, with a certified concentration of O 2 of less than 0.05%, or (C) NO in nitrogen, with a certified concentration of O 2 of less than 0.05%, and (ii) a span gas that consists of (A) ambient air in a well-ventilated area, with a presumed certified concentration of 20.9% O 2 , or (B) O 2 in nitrogen that has a certified concentration of O 2 that is (I) within the measuring range, specified by the analyzer’s manufacturer, for the O 2 cell, and (II) at least 5% and at most 20.9%; (b) for CO, (i) a zero gas that consists of (A) ambient air in a well-ventilated area, with a presumed certified concentration of 0 ppm CO, or (B) CO in nitrogen, or in air, with a certified concentration of CO of less than 0.25% of the concentration of CO in its corresponding span gas, and (ii) a span gas that consists of CO in nitrogen, or in air, with a certified concentration of CO that is (A) within the measuring range, specified by the analyzer’s manufacturer, for the CO cell, and (B) at least 200 ppm and at most 400 ppm; (c) for NO, (i) a zero gas that consists of (A) ambient air in a well-ventilated area, with a presumed certified concentration of 0 ppm NO, or (B) NO in nitrogen, with a certified concentration of NO of less than 0.25% of the concentration of NO in its corresponding span gas, and (ii) a span gas that consists of NO in nitrogen, with a certified concentration of NO that is (A) within the measuring range, specified by the analyzer’s manufacturer, for the NO cell, and (B) at least 100 ppm and at most 200 ppm; and (d) for NO 2 , (i) a zero gas that consists of (A) ambient air in a well-ventilated area, with a presumed certified concentration of 0 ppm NO 2 , or (B) NO 2 in air with a certified concentration of NO 2 of less than 0.25% of the concentration of NO 2 in its corresponding span gas, and (ii) a span gas that consists of NO 2 in air, with a certified concentration of NO 2 that is (A) within the measuring range, specified by the analyzer’s manufacturer, for the NO 2 cell, and (B) at least 50 ppm and at most 100 ppm. Certified concentration (4) A concentration of O 2 , CO, NO or NO 2 in a calibration gas is certified if the manufacturer of the gas certifies that (a) the concentration of that gas in the calibration gas is accurate within ± 2%; and (b) the calibration gas was prepared and analyzed (i) in accordance with section 2 of method entitled EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards , published in May 2012 and bearing the designation EPA/600/R-12/531, or (ii) by means of a process for measuring that concentration and for verifying its accuracy in accordance with specifications and standards of the National Institute of Standards and Technology of the United St