BME680 is a metal-oxide based chemical sensor. The sensor output is created by interaction of volatile organic compounds (VOCs) with the sensitive layer of BME680. Unlike a physical sensor (e.g. pressure sensor like BMP), chemical sensors are thus influenced by a plethora of parameters and their response is very complex. On the one hand, this implies that quantification of VOCs is not possible in a random VOC mixture like the one the sensor faces in a real world environment.