An agricultural harvesting system (10) including a chassis (12), an agricultural product moving device (40) coupled to the chassis, an airflow system (52'), a cleaning system and an airflow characterizing system (72). The cleaning system (26) is configured to receive the agricultural product from the moving device. The cleaning system is configured to receive an airflow from the airflow system. The airflow characterizing system is at least partially positioned in the airflow, and is configured to measure an airflow profile across the cleaning system. The airflow characterizing system includes a plurality of sensors (82,82') that determine airflow by measuring a thermal transfer from the sensors to the airflow. The airflow characterizing system being configured to maintain a substantially constant electrical resistance of the sensors as the airflow varies. The airflow characteristics are measured in the cleaning system and are used to improve the cleaning capacity of the harvesting system.
