Oxygen Sensor in Fires

The ability to perform in-situ measurements of oxygen concentration in fire environments at a fast rate (better than 1 sec ) is not fulfilled by available sensor systems in the marketplace. Current systems involve extraction of gas samples with the required removal of water, particulate, and interfering chemical species, which can take several seconds to complete, prior to passing the samples to a gas analyzer. To capture the flow dynamics and chemical processes in fires, oxygen concentration measurements with better temporal and spatial resolution are needed. Better understanding of fire phenomena are crucial to fire safety and abatement of fires. Southwest Sciences proposes to develop a diode laser-based sensor for the in-situ measurement of oxygen concentrations in fires. Using a newly developed vertical cavity surface-emitting laser (VCSEL) as the light source for optical absorption sensing has several advantages over other techniques such as electrochemical cells, solid-state and dye-based sensors. Phase 1 will establish the requirements for a measurement probe that is hardened for fires and evaluate the performance of the sensor design in a fire.