Teledyne 9110T instruction manual Example GPT Calculation

Model 9110T NOx Analyzer				EPA Protocol Calibration
	Equation 10-7
	PR = [NO ]STD ×	FNO		VRC
			×		≥ 2.75
		FO + FNO		FO + FNO
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 cell volume (VRC), or both will

have to be made, and TR and PR will have to be recalculated.

9.After Equation 10-5 and Equation 10-6 are satisfied, calculate the diluent air flow (FD):

Equation 10-8

FD = FT − FO − FNO

10.5.2.1. Example GPT Calculation

The 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 cell, 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 8-5 and 8-6 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 cell 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 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:

FT = 500 cm3/min (110/100) = 550 cm3/min

Because low flows are difficult to control and measure, it is often advantageous to set a higher total flow than needed. In this example, we will set FT to 2750 cm3/min.

2. Determine the highest NO concentration, [NO]OUT, required at the output manifold,:

[NO]OUT = 0.5 ppm (90/100) = 0.45 ppm

3. Calculate the NO flow (FNO) required to generate the NO concentration [NO]OUT:

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