VOCs are ubiquitous in the environment, serving many vital roles as fuels, solvents, cleaners, feedstocks and sterilants. Some of these chemicals are also harmful, leading to eye, nose and throat irritation; loss of coordination; and even liver, kidney and central nervous system damage with long term exposure. This is why monitoring is so important.
What is the difference between a VOC sensor and a co2 sensor?
Voc sensor are able to achieve impressive sensitivities and very low detection limits, but a range of factors affect sensor performance. These factors include sensor drift, sensor cross-sensitivity to other gases and a range of environmental conditions. In addition, the complexity of ambient VOC concentrations and mixtures means quantification is a significant challenge for these sensors compared to gas-phase or criteria pollutants.
Temperature and humidity are two of the key environmental factors that impact voc sensor performance. Humidity is particularly important because it can interfere with the interaction between the VOCs and the sensor material, leading to lower sensitivity and slower response times. To address this, VOC sensors often incorporate temperature and humidity compensation mechanisms to improve their accuracy.
During the FRAPPE-DISCOVER-AQ campaign, our team deployed two low-cost sensor systems at the Platteville Atmospheric Observatory (PAO) in Colorado. These sensor systems were co-located with a proton transfer reaction quadrupole mass spectrometer, providing speciated VOC data. Located to the northeast of a city, with proximity to oil and gas operations, this site offered a unique opportunity to test these sensors in dynamic environmental conditions.