A system for testing devices for detecting airborne particulate matter generates a first airflow and a second airflow. The second airflow is filtered to remove ambient airborne particulate matter from the second airflow, and particulate matter to be detected is aerosolized and introduced into the second airflow. The second airflow is sampled by an optical particle counter to determine an amount of particulate matter released into the second airflow. The first and second airflows are combined, and the combined airflows are sampled by one or more detecting devices to be tested. Detection results of the tested detecting devices are compared with the amount of particulate matter released into the second airflow as determined by the optical particle counter to assess the accuracy and functionality of the detecting devices.