Laser Stark spectrometer for the measurement of ammonia in flue gas.
The physical background of a laser Stark spectrometer dedicated to the measurement of ammonia slip through DeNo(x) reactors in power stations is treated. The dependence of the ammonia measurement on temperature and pressure variations is derived and verified experimentally. Selection of spectral lines with both a good absorption coefficient and a high sensitivity to the Stark effect, within the range of the CO(2) laser, has been carried out. If a (12)CO(2) laser is used at a temperature of 573 K and at atmospheric pressure, the 10R8 laser line is recommended for best results. The 10R18 line of the (13)CO(2) laser yields a still higher sensitivity (detection limit 0.4 ppm) for a moderate electric field. Theoretical predictions for the sensitivity of ammonia detection are compared with experimental data. Results of measurements in an industrial environment are presented.
Verhage
A J
AJ
Rooth
R A
RA
Wouters
L W
LW