TUNABLE DIODE LASER
FAST IN-SITU CROSS-STACK MEASUREMENTS
Tunable Diode Laser ( TDL ) sensors use a single-line “ monochromatic ” spectroscopy technique that offers highly stable calibration , a continuous , fast , in-situ measurement , and the avoidance of crossinterference from other gases .
The TDL system consists of a laser light source , transmitting optics , an optically accessible absorbing medium , receiving optics and detector ( s ). The signal information is held in the gas absorption line shape , which is obtained by scanning the laser wavelength over the specific absorption line . This causes a reduction of the measured signal intensity , which is detected by a photodiode and used to determine the gas concentration and other properties .
Our TDL analyzers use a second harmonic detection ( 2f ) modulation technique that delivers greater accuracy , sensitivity , and reliability of measurement , especially in low ppm-level measurements .
FIG . 1 : CLOSE-UP OF THE LINE LOCK SYSTEM SHOWING THE CUVETTE AND BEAM SPLITTER
FIG . 2 : THE LASER 3 PLUS INSTALLED ACROSS A STACK , WITH LINE LOCK SYSTEM ( CIRCLED )
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