A Gravimetry-Based Fine Particle Concentration Measurement System for Humid Environment Using Graphene Oxide Layer

Abstract

Recent studies have developed fine particle measurement systems using many methods. However, most of them are high-cost and unsuitable for harsh conditions. This study introduces a portable fine particle concentration system based on a gravimetry principle for air quality measurement in a highly humid environment. This study used a bare QCM (Q1) and graphene oxide-coated QCM (Q2) as the fine particle sensors. All sensors were installed inside a sensor box and tested at two different humidity levels: 75% (normal humidity) and 95% (high humidity). The sensors were tested using fine particle emissions (diameter 0.01 - 2.5 µm) emitted from several combustion sources (three biomass samples). A handheld particle concentration measurement device was used as the comparator for the measurement system. The results show that the uncoated QCM has a lower frequency response than the GO-coated QCM. The bare QCM does not show significant accuracy and linearity. As expected, the coated QCM performs better than the uncoated QCM, where the peak accuracies of the coated QCM are 98% and 99% for normal and high humidities. The linearity and sensitivity levels of the coated QCM are 95-99% and 0.59 – 1.76 Hz m3 ug-1. These performances confirm the reliability and ability of the developed system using GO layer and QCM to be employed as a fine particle emission sensing device in a humid environment.