Investigation of SO3absorption line for in situ gas detection inside combustion plants using a 4-μm-band laser source.
We have investigated 4-μm-band SO3absorption lines for in situSO3detection using a mid-infrared laser source based on difference frequency generation in a quasi-phase-matched LiNbO3waveguide. In the wavelength range of 4.09400-4.10600 μm, there were strong SO3absorption lines. The maximum absorption coefficient at a concentration of 170 ppmv was estimated to be about 3.2×10-5cm-1at a gas temperature of 190°C. In coexistence with H2O, the reduction of the SO3absorption peak height was observed, which was caused by sulfuric acid formation. We discuss a method of using an SO3equilibrium curve to derive the total SO3molecule concentration.
A
A
Tokura
O
O
Tadanaga
T
T
Nishimiya
K
K
Muta
N
N
Kamiyama
M
M
Yonemura
S
S
Fujii
Y
Y
Tsumura
M
M
Abe
H
H
Takenouchi
K
K
Kenmotsu
Y
Y
Sakai