Teledyne API Model 200A NOX Analyzer Instruction Manual, 02246, Rev. G, DCN 5247
NOTE
If tr is >2 minutes or if PR is <2.75 ppm-min, changes in flow conditions
(FT, FO, FNO) or in the reaction chamber volume (VRC), or both will
have to be made, and tr and PR will have to be re-calculated.
9. After equations 7-5 and 7-6 are satisfied, calculate the diluent air flow (FD) using
Equation
7-7:
NOO Equation 7-7 TD FFFF
7.8.4.3 Example GPT Calculation
Following is an example calculation that can be used to determine whether an existing GPT
calibrator will meet the required conditions for a specific calibration. For this example, it is
assumed that only the volume of the reaction chamber, VRC, and the concentration of the NO
standard, [NO]STD, are known. All flow settings (FNO, FO, FT, and FD) will be calculated. In many
uses, these flow settings are known and need only to be substituted in Equations 7-5 and 7-6 to
verify the required conditions. Before doing any calculations, the URL and flow demand of the
analyzer being calibrated must be known. Operating parameters are determined from the
operations manual:
Upper range limit = 0.5 ppm, and
Flow demand = 500 cm3/min.
Volume of calibrator reaction chamber is determined by physical measurement:
VRC = 180 cm3
The concentration of the NO standard gas to be used is determined by reference against an
NIST-SRM (Section 2.0.7, Q.A. Handbook):
[NO]STD = 50.5 ppm
1. Determine the minimum total flow (FT) required at the output manifold using Equation 7-
1:
FT = 500 cm3/min (110/100) = 550 cm3/min
7-18
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