Development of a low-cost device for observing indoor particle levels associated with source activities in the home

A small instrument package was developed to continuously observe particles, carbon dioxide,<br>temperature and movement at relatively low cost. Four identical packages were built and co-<br>located in a test home alongside a wide range of more sophisticated instruments. The<br>instruments were exposed to common indoor particle sources in a semi-controlled experiment,<br>and during normal occupation of the house.<br>Results indicate that each sensor requires individual calibration. The responses of the CO2<br>and particle sensors were highly consistent and correlated with much more expensive<br>instruments. The combination of CO2 and movement data was able to indicate the presence of<br>persons in the room, although not unambiguously. Trials are ongoing to investigate the impact<br>of instrument location within the home. The particle sensor responded clearly to cooking<br>sources and the infiltration of outdoor particles on evenings with elevated ambient PM10.