Preparation and Characterization of Affordable Experimental Setup for Particulate Matter Sensing

The interest in particulate matter (PM) sensors has significantly increased over the last decade. It is crucial to have a proper experimental setup to test these sensors. However, most devices used in PM test setups, both for generating and measuring PM, are bulky and expensive. This study aims to solve this issue by designing a cost-effective experimental setup. The setup includes a custom-made PM generator, small-sized laser and quartz crystal microbalance (QCM) sensors. The PM generator can produce PM from three different sources: dry powder, liquid suspension, and combustion. The QCM is used to overcome the limitations of laser sensors for sensing ultra-fine particles. Moreover, the performance of the QCM sensor has been investigated with various PM sources and ambient conditions. The study reveals that the QCM response can be influenced by the PM source and ambient conditions. Changes in PM composition and size significantly impact the QCM response. Additionally, relative humidity (RH) can alter the sensor response by up to 22%. While the temperature change in the flow has an insignificant effect on the bare QCM response, increasing the temperature from 25 °C to 30 °C results in a 12% change in the QCM response for the grease-coated sensor. Notably, the QCM sensor demonstrates the best response with small-sized smoke PMs, with the least impact from ambient conditions. The laser sensors work very well with large particles; however, they struggle with small-sized smoke PMs.