Transmitter Overview - Emerson Rosemount 2051 Reference Manual

Introduction
March 2024
1.3

Transmitter overview

The Rosemount 2051C Coplanar design is offered for Differential Pressure (DP) and
Gage Pressure (GP) measurements where it uses Emerson capacitance sensor technology.
Piezoresistive sensor technology is used in the Rosemount 2051T measurements.
The major components of the Rosemount 2051C are the sensor module and the electronics
housing. The sensor module contains the oil filled sensor system (isolating diaphragms,
oil fill system, and sensor) and the sensor electronics. The sensor electronics are installed
within the sensor module and include a temperature sensor (RTD), a memory module, and
the capacitance to digital signal converter (C/D converter). The electrical signals from the
sensor module are transmitted to the output electronics in the electronics housing. The
electronics housing contains the output electronics board, the local zero and span buttons,
and the terminal block. The basic block diagram of the Rosemount 2051CD is illustrated in
Figure
For the Rosemount 2051C design, pressure is applied to the isolating diaphragms, the
oil deflects the center diaphragm, which then changes the capacitance. This capacitance
signal is then changed to a digital signal in the C/D converter. The microprocessor then
takes the signals from the RTD and C/D converter calculates the correct output of the
transmitter. This signal is then sent to the D/A converter, which converts the signal back to
an analog signal and superimposes the HART
8
1-1.
signal on the 4-20 mA output.
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Reference Manual
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