A stable and well-maintained mine ventilation system is the key to ensure a safe and healthy working environment for miners. A sudden, unplanned, and significant change in airflow termed as abnormal airflow is frequently observed in mine ventilation. Some abnormal airflows can return to normal without manual intervention, however, some abnormal airflows may cause catastrophic accidents if left unattended. In addition, abnormal airflow may be a consequence of an accident such as a blocked airflow route due to roof fall. Promptly diagnosing and locating the cause of abnormal airflow can help prevent accidents. Researchers at the National Institute for Occupational Safety and Health (NIOSH) have developed a method to diagnose the cause of abnormal airflow for underground mine ventilation systems. The purpose of this paper is to verify the developed method using experimental tests conducted at a NIOSH's experimental mine. The airflows were monitored by real-time atmospheric monitoring system installed in the experimental mine during the tests. The developed abnormal airflow diagnosing method, based on the resistance sensitivity and matching method, has been proven very reliable.
