Teledyne M201E manual 4NH3 + 5O2 → 4NO + 6H2O

M201E Ammonia Analyzer Teledyne API Model M201E NH3 Analyzer Operator Manual

Figure 1-3. M201E and M501 NH3, with Zero and Span Valve Options Pneumatic Flow

1.1THEORY OF OPERATION

The Teledyne-API Model M201E 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 M200E 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 M201E 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

10 05206H DCN5910