Dwyer AQS-1 AQStick ambient VOC monitor

The AQS-1 AQStick ambient volatile organic compound (VOC) monitor is used to monitor ambient air quality by detecting the VOC content in the air. Some common sources of VOC contamination are carpets, building materials, paints, cleaners and tobacco smoke. Even low concentrations of these compounds can affect building occupants’ comfort. A computer’s USB port provides power for the sensor and the LED lights which change colour in accordance with the ambient air quality.

In order to correspond with ASHRAE’s standards for air quality, the VOC reading from the monitor is converted from a percentage contaminated to an equivalent PPM reading of CO₂. The percentage contaminated multiplied by 2000 PPM of CO₂ gives the equivalent concentration of CO₂. From the factory, the LED is green under 1000 PPM CO₂, yellow for 1000 to 1500 PPM CO₂ and red above 1500 PPM CO₂. These factory values can be changed using the free online software. When using the software, the monitor can log and graph how building conditions change over time.