4.0THE M200EU-NOYCONVERTER
4.1Principle of Operation
The T-API Model M200EU with NOy Option is designed to measure the concentration of NO, NO2, and other compounds that are too unstable to be measured when taken in through the normal ambient air sample inlet system. Please refer to the M200EU manual supplied with this system for a general discussion of the operation of a NOx analyzer. The suite of compounds known collectively as NOy is composed of roughly 30 compounds. There is some disagreement over whether certain compounds should be on the list. The NOy measurement is generally done in conjunction with a standard NOx measurement, with the difference between the two being the concentration of the unstable compounds, sometimes referred to as NOz. The analyzer measures two independent gas streams. One bypasses the external converter and measures NO in the sample. The other pulls the sample through the external converter and is displayed as NOy. Under normal calibration conditions the NOy measurement is equivalent to the delivered NOx calibration gases.
The system is composed of 3 modules:
The M200EU analyzer, without a Moly converter.
This is the location of the optional Zero/Span Valves.
A Bypass Pump Module containing:
bypass pump
flow control
sample filtration
moly temperature control
pneumatic provisions for calibration
optional sample Dryers to remove moisture
Externally mounted molybdenum converter
The M200EU w/NOy Option system allows the converter to be mounted at the sample inlet point. This configuration provides minimal time delay between the sample inlet port and the remotely mounted molybdenum converter. Minimizing the transit time between the sample inlet and converter enables the conversion of labile components of NOy. The equation for the conversion is:
315oC
3 NOY + Mo ---> 3 NO + MoO3