Teledyne T201 manual Theory of Operation, Outlined in the following equations

T201 Ammonia Analyzer Teledyne API Model T201 NH3 Analyzer Operator Manual

1.1THEORY OF OPERATION

The Teledyne-API Model T201 analyzer measures ammonia by oxidizing it to nitric oxide by the following reaction:

4NH3 + 5O2  4NO + 6H2O

	The resulting nitric oxide is then measured by the chemiluminescent
	reaction with ozone. Consult Section 10.1 in the T200 manual (provided
	with this instrument) for more details on the nitric oxide measurement.
	The analyzer uses two converters to oxidize the different sample gases. A
	high temperature catalytic converter, the M501 NH3, converts NH3 and
	NOx into NO creating the TNx channel. A second converter, housed inside
	the T201 analyzer and consisting of heated molybdenum, converts all of
	the NOx in the sample to NO producing the NOx channel. The nitric oxide
	channel is measured while bypassing both the M501 NH3 and
	molybdenum converter. A Nafion® drier operated in reflux mode, is
	installed prior to the molybdenum converter and the AutoZero valve. The
	drier removes ammonia and water from the switched stream. The
	ammonia would have otherwise been converted by the molybdenum and
	registered as NOx. This location provides the drier with continuous flow,
	thereby allowing it to stabilize faster.
Note	Due to the Nafion® drier, the analyzer has a maximum ammonia range of
	2.0 PPM.
	The calculated gas concentrations, ammonia and nitrogen dioxide, are
	computed from the differences between the measured channels, as
	outlined in the following equations:
	NO (Nitric Oxide) Concentration = Measured
	TNx (Total Nitrogen) Concentration = Measured (NH3 + NO2 + NO)
	NOx (Total Nitrogen – Ammonia) Concentration =	Measured
	(NO2 + NO)
	NH3 (Ammonia) Concentration = Calculated as follows:
	[(TNx - NOx) / (NH3_CE_FACTOR1)]
	NO2 (Nitrogen Dioxide) Concentration = Calculated as follows:
	[(NOx – NO) / (NO2_CE_FACTOR1)]
Note	The nitrogen dioxide efficiency factor (NO2_CE_FACTOR1) must be
	calculated by conducting a GPT (gas phase titration) as described in Section

8.3.3 of the T200 manual and Section 6.0 of this manual. This value gives a good indication of how well the molybdenum is converting nitrogen dioxide into nitric oxide. In a properly functioning analyzer the value should be close to 1.0. It is recommended that the molybdenum efficiency be checked every three months.

10 07271B DCN6646