The Elliptical Advantage

• • Flow boundary layers attached to probe surface
• • No separation effects
• • No vacuum effects
• • No vortex generation
• • Low drag coefficient
• • High repeatability
• • Low static pressure signal affected by separation
• • Vacuum effects limit turndown ratio to 4 to 1
• High drag coefficient creates high pressure loss

• The Series JFM-S FloSen® Airflow Measuring Stations provide accurate, repeatable measurement of air movement in HVAC ducts. The Probes patented elliptically shaped sensor design with improved aerodynamic characteristics outperforms more traditional devices, and overcomes loss of accuracy caused by fluid separation at the sensor body. It is designed to maintain a constant parallel airflow pattern over the static sensing ports for more accurate, steady signals under all duct conditions. The elimination of separation results in a stabilized static pressure signal, helping to eliminate “hunting” during fan control.
  
  The total and static pressure measuring points are distributed for equal-area averaging of flows resulting in improved accuracy and reliability. This design permits accurate and stable measurement in highly turbulent flow locations with directional pitch and yaw varying up to 20 degrees without the need for air flow straighteners which restrict airflow and can easily become clogged. The elliptical shape of the FloSen® Airflow Probes allows air to glide unrestricted around the aerodynamically designed sensors and offers the lowest pressure drop of any airflow measuring device available minimizing HVAC operating costs.
  
  The JFM-S Airflow Measuring Stations have been designed for complete installation between ducts. The quantity of FloSen® Airflow Measuring Probes selected for each Flow Station is based on ASHRAE and AMCA standards to produce assured airflow measuring accuracy over a flow turn-down ratio of 17:1.