An Experimental Evaluation of Low-Cost MQ-Series LPG Sensors under Varying Temperature Conditions

This study presents a comparative experimental evaluation of four low-cost MQ-series Liquefied Petroleum Gas (LPG) sensors (MQ2, MQ4, MQ5, and MQ6) under controlled temperature variations to assess their accuracy and reliability for practical gas detection applications. Although MQ sensors are widely employed in low-cost gas monitoring systems, comprehensive comparative analyses utilizing industry-grade reference instruments remain limited, particularly under varying thermal conditions. Experiments were conducted within a temperature range of 15–31 °C, and the results were validated against the Bosean BTY-S100 reference instrument. Among the tested sensors, the MQ2 exhibited the best overall performance, achieving a high coefficient of determination (R² = 0.96), low Root Mean Square Error (RMSE) of 7–12, Relative Root Mean Square Error (RRMSE) of 2–7%, and deviation below 10%. These findings demonstrate that the MQ2 sensor offers superior accuracy, stability, and consistency across different temperature ranges, underscoring its potential as a reliable and cost-effective solution for practical LPG detection applications.