Emerson 00809-0100-4514, 1154 manual Δ-Cell

Page 32

Rosemount 1154

Reference Manual

00809-0100-4514, Rev BA January 2008

K1	is a constant.
C1	is the capacitance between the high pressure side and the sensing
	diaphragm.

C2 is the capacitance between the low pressure side and the sensing diaphragm.

fVp – p	Iref
fVp – p	= --------------------
	C1 + C2

Where:

Iref is the current source.

Vp-pis the peak-to-peak oscillation voltage.

fis the oscillation frequency.

Idiff = fVp – p(C2–C1)

Where:

Idiff is the difference in current between C1 and C2.

Therefore:

P =	Constant × I		= I	⎛ C2 – C1⎞
P =	Constant × I		= I	⎜ --------------------⎟
		diff		ref⎝ C2 + C1⎠

Figure 4-1. The δ-Cell.

Leadwires

Isolating

Diaphragm

Capacitor

Plates

Sensing

Diaphragm

Rigid

Insulation

Silicone Oil

Welded Seals

4-2

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Contents Rosemount Reference ManualImportant Notice -- Errata Rosemount 1154 Alphaline Nuclear Pressure Transmitter Return of Material New Old Changes Revision StatusChanges From June 1999 to January Rosemount Table of Contents Section Maintenance TroubleshootingSpecifications Reference Data TOC-3 TOC-4 Section Introduction Overview About the TransmitterRosemount Section Installation Overview General ConsiderationsMechanical Considerations Process ConnectionsRosemount Conduit Electrical ConsiderationsTransmitter Wiring Connections Mechanical InstallationProcedures Pressure Dimension Range CodeLiquid Service ElectricalTransmitter Terminal Block Rosemount Overview Calibration Span Adjustment Zero AdjustmentSection Calibration Calibration Procedures Zero and Span AdjustmentZero and Span Adjustment Screws Linearity Adjustment Damping Adjustment Linearity and Damping AdjustmentRosemount Calculate zero adjustment correction in terms of pressure Rosemount Section Operation Overview Transmitter OperationΔ-Cell Linearity Adjustment DemodulatorFV Iref Maintenance Troubleshooting OverviewSafety Messages Test Terminals Board CheckoutSensing Module Checkout Disassembly Procedure Process Flange RemovalRosemount 1154 Parts List Part DescriptionReassembly Procedure Rosemount Process Flange Reassembly On Next Post Assembly TestsSymptom Potential Source Corrective Action Check for adequate voltage to the transmitter Specifications and Reference Data Nuclear SpecificationsPerformance Specifications Range Code Overpressure Effect Range Code Response Time Functional SpecificationsRange Code Static Pressure Zero Effect Range Code Pressure Ranges 25 to 0-150 inH2O 0-6.22 to 0-37.3 kPaPhysical Specifications Range Code Overpressure LimitRosemount Ordering Information Rosemount 1154DP, 1154HP, and 1154GP Spare Parts Rosemount 1154DP 1154HP 1154GP Part Description Order NoFor use with existing N0026 transmitter only Spare Parts Shelf Life Important Notice Rosemount Current Control Current Limit Index-2 Page ¢00809-XXXX-XXXX ¤