6. Gas Flow Meter Technologies Type Mass or Volume Turndown Range Low Flow Dirt Line Sizes Pressure Drop ($) Thermal Mass 1,000:1 Yes OK 1/8โ โ Insertion Low DP Volume 10:1 No Bad 1/8โ- Insertion High Turbine Volume 50:1 No Bad 1/4โ- Insertion High Vortex Volume 25:1 No Bad 1โ- Insertion Low Coriolis Mass 100:1 No OK 1/8โ-10โ Medium Ultrasonic Volume 100:1 Yes Bad 2โ โ 120โ Low