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

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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

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Contents Teledyne Hastings Manual Print History Table of Contents 12.0 Features General InformationOperating Principle Operating PrincipleReceiving and Inspection Installation Instructions TransducerFilters Power SupplyCables Electrical Zero Check Using the Flowmeter Flowmeter Factory Calibrated for a Special Gas Output SignalGas Mixtures Repeatability AccuracyOver-range Pressure Effects Standard TransducersLow Pressure Drop Transducers High Pressure Transducers OptionalTemperature Effects Ambient Temperatures TransducerPower Supply Gas TemperatureDifferential Pressure Typical Pressure DropsChanges in DP with Changes in Line Pressure Increase in Line PressureDecrease in Line Pressure DP Increase Due to Fouling of the TransducerCalibration Procedures CalibrationTransducer Maintenance Transducers CleaningPower Supply Troubleshooting Damage to the TransducerAccessories Options and AccessoriesDouble Point Relay Flowmeter/Alarm DNALL-P Totalizers TNALL-P DescriptionsChassis Model NALL-C MaintenanceCurrent Converter NAll-P/CC Warranty Repair Policy Warranty and RepairNon-Warranty Repair Policy