Teledyne NALL Differential Pressure, Typical Pressure Drops, Increase in Line Pressure

8.0 DIFFERENTIAL PRESSURE

8.1TYPICAL PRESSURE DROPS

The differential pressure drop (DP) across the Hastings HS-Series Mass Flow Transducer can vary between 0.50” H2O depending upon the transducer’s range. Other pressure drops are listed below and all are based upon full-scale flow rates of air at 0°C and 760 Torr.

8.2CHANGES IN DP WITH CHANGES IN LINE PRESSURE

The typical differential pressure drops listed in the table above are for operation at atmospheric pressure. As the line pressure changes, the differential pressure drop for the same flow rate will also change.

8.2.1Increase in Line Pressure

The differential pressure drop across the transducer will decrease proportionately as the absolute line pressure increases as stated in the following equation:

DP = DP (@STP) Pressure (STD)

Pressure (ACT)

Where DP = Transducer differential pressure at 0oC and 760 Torr

Pressure (STD) = 14.7 psia

Pressure (ACT) = 14.7 psia + line pressure

Manual 111-082010_Nall Mass Flowmeters Page 16 of 23