There are many kinds of nitrogen oxide exhausted from vehicles using fuel, but most of them are changed into NO2 after a certain period of time in the natural world and a very small amount of them fatally affect the human body. The very good level of NO2 gas concentration for human body in the atmosphere is below 100μg/m3 and the bad level is over 400μg/m3.
Thus, accurate estimation of NO2 concentration is very important to protect human lives.
Kim Yong Hyok, a researcher at the Faculty of Electronics, designed the structure of a three electrodes system (3ES)-electrochemical NO2 gas sensor and analyzed the action principle based on Nafion membrane material by using qualitative analysis method. In addition, he established the manufacturing process of the sensor and experimentally analyzed the NO2 sensing property depending on the bias voltage properties.
He proved that the optimal bias voltage range is 0.9~1.2V and the sensitivity is 0.31μA/ppm, and that it can sense NO2 gas up to 100ppm linearly.
You can find more information in his paper “Design of Three Electrodes - Electrochemical Nitrogen Oxide Gas Sensors and its Bias Characteristics” in “Journal of Analog and Digital Devices” (EI).
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