Teledyne 9110T instruction manual NOX and NO2 Determination, Tensit

Model 9110T NOx Analyzer Principles of Operation

Figure 13-1: Reaction Cell with PMT Tube and Optical Filter

The narrowness of this band of sensitivity allows the 9110T to ignore extraneous light and radiation that might interfere with the 9110T’s measurement. For instance, some oxides of sulfur can also be chemiluminescent emitters when in contact with O3 but give off light at much shorter wavelengths (usually around 260nm to 480nm).

	140
	Visible		Infrared 
	120	Spectrum
units)
	100
(arbitrary	80				NO + O3 Emission Spectrum
		PMT
		Response
y	60
tensit	40
In
	20					Optical Hi-Pass Filter Performance
	0
	0.5	0.7		0.9	1.1	1.3	1.5	1.7	1.9

Wavelength (micrometers)

Area of Sensitivity

Figure 13-2: 9110T Sensitivity Spectrum

13.1.3. NOX AND NO2 DETERMINATION

The only gas that is actually measured by the 9110T is NO. NO2, and therefore NOx (which is defined here as the sum of NO and NO2 in the sample gas), contained in the gas is not detected because NO2 does not react with O3 to create chemiluminescence.

Teledyne Analytical Instruments 321