Advancement of LED-Based Hazardous Gas Sensors for Space Applications

摘要

Hazardous gas detection is essential for ensuring safety and functionality before, during, and after a space mission. Gas detection protocols will become increasingly necessary as the range of human activities in space moves further from the Earth-moon system; this advancement brings with it, a need for such sensors to function in a variety of environments. Any sensor implemented would need to selectively discriminate between a variety of gases in across ranges of pressure and temperature while maintaining accuracy and is not affected by bath gas' spectral features. For this purpose, a sensor has been developed that relies on a light-emitting diode (LED) and principles of absorption spectroscopy to detect various gases that are either harmful to humans or indicative of harmful situations such as fire, smoldering, or gas leaks. Such a sensor is the focus of this paper. Described herein is a bench-top prototype sensor capable of detecting both carbon dioxide (CO_2) and nitrous oxide (N_2O) using a single pulse-modulated LED. These gases in particular were chosen because of their prevalence in space environments and the potential cognitive dangers associated below lethal limits.