Data-Driven Analysis of Voltage Tolerance Effects on MOS Sensors: Ethanol Detection and Stability

Metal oxide semiconductor (MOS) based gas sensors are widely used for volatile organic compound (VOC) detection in advanced research experiments and applications. However, their performance, particularly in terms of response time and detection accuracy, may be influenced by variations in supply voltage. According to datasheets of the most commercial MOS sensors, the sensors tolerate a supply voltage of 5±0.2 volts. This study investigates the voltage error tolerance of MQ-series gas sensors under ethanol exposure—a common VOC—focusing on its impact on response time at 90% of full response. Given their non-selective nature, these sensors are employed in diverse gas detection scenarios, yet their heating resistor's stability is directly affected by voltage fluctuations due to Joule's law. In practical applications, an adjustable detection threshold is often set, but inconsistent supply voltages may lead to variations in VOC detection timing. This research examines how deviations from the nominal 5V±0.2 supply influence sensor response, providing insights into the importance of voltage precision in gas detection systems. The findings aim to guide optimal sensor implementation in both hobbyist and research-oriented projects where reliable VOC detection is critical.