Primary airflow is used to dry the coal and distribute the coal to the burners on the proper PA (primary air) Curve. Airflow measurements are key to mill efficiency, minimizing thermal NOx, and optimizing combustion. Extreme temperature stratification often found in primary airflow applications - after the tempering and hot air have mixed - can cause inaccurate and non-repeatable measurements for most airflow measurement technologies. Furthermore, some technologies cannot withstand the high temperatures – up to 800°F - often found in these applications. Key challenges in this application include the dynamic temperature and airflow changes caused by the hot and tempering air dampers, limited straight pipe runs, and particulate-laden airflow. Air Monitor offers a highly accurate and reliable primary airflow measurement solution.