Unitronic has launched a sensor module designed to enable quick, accurate detection of volatile organic compounds (VOCs) in the air. The Unitronic Sensor Module VOC (USM VOC) is based the TGS 2201 semiconductor sensor from Figaro. Instead of the usual resistance-based operating principle, the module monitors electrical charge shifts in the sensor element. This enables both very fast response to changes and shorter recovery times.


The sensor, which reacts to various volatile substances including carbon monoxide (CO), toluene and ethanol, also features detection resolution nearly twice as good as conventional resistance measurement methods, especially at low concentration levels.


A special digital sampling process developed by Unitronic for the USM VOC, enables the module to take advantage of the very short response time and measurement cycle of the gas sensor without any restrictions while also achieving very high accuracy. The USM-VOC responds to releases of harmful gasses up to 20% faster than conventional resistive gas sensors, and it can detect the actual gas concentration in the air much faster. For example, a concentration of just 30 parts per billion (ppb) is sufficient for the precise detection of toluene.


The module measures 30x30 mm and operates from a 5 V supply voltage. It features both analogue and digital (UART) outputs to enable easy integration into user circuits.


Image: Unitronic