Development of a multiple gas analyzer using cavity ringdown spectroscopy for use in advanced fire detection.

Area of Science:

• Combustion Science
• Analytical Chemistry
• Sensor Technology

Background:

• Traditional fire detection methods have limitations in sensitivity and speed.
• Cavity Ringdown Spectroscopy (CRDS) offers high sensitivity for gas detection.
• The need for advanced fire detection systems in various environments is growing.

Purpose of the Study:

• To evaluate the feasibility of using a portable Cavity Ringdown Spectroscopy (CRDS) apparatus as a fire detector.
• To demonstrate the capability of CRDS in detecting combustion gases from small-scale fires.
• To assess CRDS performance in different fire testing environments.

Main Methods:

• A portable CRDS apparatus utilizing two lasers was employed.
• CRDS was used to detect carbon monoxide (CO), carbon dioxide (CO2), hydrogen cyanide (HCN), and acetylene (C2H2).
• Measurements were taken from effluents of test fires in the Fire Emulator/Detector Evaluator (FE/DE) and a small room at NIST.

Main Results:

• CRDS successfully detected CO, CO2, HCN, and C2H2 from smoldering paper fires and other small fires.
• Peak concentrations detected included 420 ppm CO, 1600 ppm CO2, 530 ppb HCN, and 440 ppb C2H2 in the FE/DE test.
• In a small room test, peak concentrations reached 270 ppm CO, 2100 ppm CO2, and 310 ppb C2H2.

Conclusions:

• The study demonstrates the feasibility of employing CRDS technology for fire detection.
• CRDS offers near-simultaneous detection of multiple key combustion gases.
• This research supports the development of next-generation, highly sensitive fire detection systems.