What are chemical species gas sensors and how do they work?
Dr. Gary Hunter: Simply speaking, chemical species gas sensors measure the chemical species in the atmosphere, rather than in the ground or water. There are a number of species in the atmosphere – nitrogen, oxygen (O2), carbon dioxide (CO2), carbon monoxide (CO), and others. So, some of the chemical sensors we work on are sensors that measure hydrogen, hydrocarbons, oxygen, carbon monoxide, carbon dioxide, nitrogen oxides (NOx), and other species, which have relevance to aerospace applications. How do they work? There are different ways of measuring chemical species, and each technique has its advantages and disadvantages. The technique that we use has to do with small microsensors, and they work by coming in contact with the gas in the environment and having a chemical reaction with it. That chemical reaction produces an electrical signal that we measure, so one can begin to understand what’s going on in the environment. What we try to measure depends on the application. For example,
