Multi-Hazard Sensor for Miners

DESCRIPTION (provided by applicant): The National Institute for Occupational Safety and Health conducts activities to assure safe and healthful conditions for American workers. The mining industry presents particularly challenging safety and health needs. In particular, miners are continuously exposed to methane, carbon monoxide, diesel fumes and particulate matter, and dust. At low concentrations, chronic exposure to these airborne hazards can cause miner health problems, but at high concentrations the haz ards are immediately life threatening due to their toxicity and potential for explosion. Thus, there is a need for technology able to measure the exposure of miners to these hazards as well as to warn miners of immediately dangerous conditions prior to ent ering a potentially hazardous area. To this end, Physical Sciences Inc. (PSI) proposes a Research and Development project intended to result, after Phases I - III, in a novel product or suite of products that provide quantitative standoff sensing of the ai rborne mining hazards. The product(s) resulting from this research and development will function like and will supplement the flashlight illumination source mounted on a miner's helmet. Two technologies that PSI has previously developed into robust compact industrial sensor products form the foundation for the proposed miner safety sensor suite. These underlying technologies are standoff Tunable Diode Laser Absorption Spectroscopy (TDLAS) and angle-resolved laser scattering. The sensor suite combining these techniques will project from the helmet eye-safe laser beams that illuminate mine walls and structures, as well as airborne particles. Additional helmet-mounted optical components collect some of the laser light scattered from the walls and particles. A s ignal processor, comprising a single battery-powered circuit board, analyzes the collected laser light and determines the concentrations of each hazard along the path of the laser beam. Concentration data is stored for recording exposure to health hazards, and real-time audible alarms warn of immediate or imminent danger. The Phase I research and development project objective is to demonstrate the feasibility of developing the envisioned sensor suite. To this end, PSI will design, build a bench top prototyp e, and test a novel helmet mountable TDLAS configuration that senses both methane and carbon monoxide with the sensitivity and standoff distance appropriate for miner health and safety. PSI will also design, build, and evaluate a sensor that receives and r esolves the angular distribution of light backscattered towards the helmet from dust and diesel particulate matter illuminated by the TDLAS laser beam or a supplemental laser. Data acquired will indicate the feasibility of using this light scattering infor mation to deduce the concentration of each particle class. The Phase I research will provide a solid foundation for advanced development of the sensor suite in Phase II. The health and safety of miners may be compromised by airborne contaminants including methane, carbon monoxide, diesel fumes and particulate matter, and dust. This research will lead to the development of a helmet-mounted integrated standoff sensor product that will sense and measure these hazards from a distance. The sensors will warn the miner prior to entry into a potentially explosive or toxic atmosphere, as well as record total exposure to inhalation hazards.