Filter
Top Products
Teledyne API Model 201A NH
3
Analyzer Instruction Manual, 04689, Rev. B1
1.0 M201A AMMONIA ANALYZER
This manual is to be used in conjunction with the M200A NOx Analyzer manual p/n
02246 supplied with this instrument.
The M201A Ammonia Analyzer consists of a modified M200A Nitrogen Oxides Analyzer
and M501NH Ammonia Converter:
A functional block diagram of the system is shown in Figure 1.
The instrument comes in three pneumatic configurations:
• The basic system is shown in Figure 3;
• The M201A with Z/S valves is shown in Figure 4;
• The M201A with External Calibrator Option (ECO) is shown in Figure 5.
Figure 2 can be used to connect the M201A system for installation. Please note that for a
M201A with either a Zero/Span or ECO option, you must connect the umbilical cord,
02255, between the analyzer and the converter assembly.
1.1 Principle of Operation
The Teledyne API Model 201A Analyzer measures ammonia by converting NH
3
to nitric
oxide by the following reaction:
4NH
3
+ 5O
2
→ 4NO + 6H
2
O
The resulting NO is then measured by the chemiluminescent reaction of NO with ozone.
Consult Section 4.1 in the M200A manual (provided with this instrument) for more
details on NO measurement.
A molybdenum converter is continuously in the pneumatic pathway, providing the TN
channel signal. The
M501NH ammonia converter is periodically switched so both
converters are in series, creating the TNx signal.
The ammonia concentration is computed by the difference between the TNx and TN
channels, as shown in the following equation:
NH
3
→ TNx - TN
See the pneumatic diagram in Figure 1.
The actual formula for computation of ammonia concentration is more complicated than
the above equation, as it includes converter efficiencies, plus sample temperature and
pressure. The difficulty in ammonia measurement is that the molybdenum converter
6