The GS-AQD, Indoor Air Quality Sensor uses an advanced MEMS metal oxide semiconductor sensor to detect poor air quality. The sensor reacts quickly to detect a broad range of VOCs such as smoke, cooking odors, bio-effluence, outdoor pollutants and from human activities. The sensor captures all VOC emissions that are completely invisible to CO2 sensors. The GS-AQD provides a linear analog signal output of 0-5 or 0-10 Vdc for connection to a build¬ing automation system, as an analog stepped output of 0-10 Vdc as well as an adjustable relay output. Optional temperature output is available.