Development of a Novel Low-Cost Automated Flux Chamber for Real-Time Monitoring of VOCs Emissions at Contaminated Sites

This study introduces
an innovative, low-cost static
flux chamber
for real-time monitoring of volatile organic compound (VOC) emissions
at contaminated sites. Compared to traditional static flux chambers,
the developed system is fully automated, eliminating the need for
continuous operator intervention in the field. The cylindrical stainless-steel
chamber (6.28 L) is equipped with internal sensors for temperature,
pressure, and humidity, and a low-cost PID sensor for VOC detection
(0.001–40 ppm). VOC flux is determined over 10 min measurement
cycles, with two micro diaphragm pumps purging the chamber to reset
concentrations. An Arduino Uno microcontroller manages the system,
enabling local data storage (SD card) and a LoRa module to send real-time
data to the cloud using IoT systems. Powered by a 12 V battery, rechargeable
via a photovoltaic panel, the system ensures continuous operation.
The prototype costs less than 1.5 k€, significantly cheaper
than commercial devices. Accuracy and repeatability were assessed
through lab-scale emission tests under dynamic conditions using various
aliphatic and aromatic VOCs. Results closely matched those from a
commercial gas analyzer and a Comsol Multiphysics numerical model,
confirming the system reliability. These findings support its potential
as a cost-effective alternative for continuous VOC monitoring at contaminated
sites.