IoT Aroma Sensor Module to Determine Beverage Alcohol Grade

Industry 4.0 is the technology of the future, which is based, among other things, on the Internet of Things (IoT) and sensors that provide online information about the production processes. Electronic noses (E-noses) are gas sensor technologies expanding IoT, contributing to better alcohol production performance and providing important information about production process parameters. In this work, we have developed a low-cost, wireless, and compactness aroma sensor module applied to the alcohol industry. We use four metal oxide sensors, MQ-2, MQ-3, MQ-4, and MQ-135, embedded in the E-nose headspace and controlled by a 32-bit ESP32 WROOM microcontroller. The alcohol grade measurements were performed on beer and wine samples. MQ-3 sensor was stable till 20% alcohol grade, and MQ-2, MQ-4, and MQ-135 sensors were regular only until 5% alcohol. Our experiments let us determined alcohol grade with precision above 92%.