Section 1 - Introduction; Product Description; Transmitter Features - Emerson Bristol 2808 Series Instruction Manual

1.1 PRODUCT DESCRIPTION

Series 2808 Transmitters convert pressure measurements into a proportional 4-20 mA or a
1 - 5 Vdc output signal that functions as the input to a controller, recorder, indicator or
similar device. These Transmitters find application in the gas, water, and process
industries that require accurate measurements over a wide range of environmental
conditions.
Series 2808 Transmitters include the following models:
2808-15B Gage Pressure Transmitter w/ internal diaphragm
2808-16B Gage Pressure Transmitter w/ flush diaphragm
2808-35B Differential Pressure Transmitter

1.2 TRANSMITTER FEATURES

The features that follow are common to all Transmitter models are described in the
following listing:.
• Pressure Sensor.
measurements.
•
Signal-Power Loop. The Transmitter requires a nominal 24 Vdc power source to
operate the signal loop, a 2-wire 4-20 mA output.
•
Available Voltage Output. For low power applications, a 1-5 Vdc output is user
configurable via an internal jumper.
• Adjustable Ranges. Transmitters are provided with coarse switch and fine pot
adjustments for range calibration. Span is adjustable from 16 to 100% of the upper
range limit, while zero is adjustable from -600 to 600% of the lower range limit for
elevation and suppression.
•
Damping. A circuit jumper selects damping periods of .275 sec or 1 ms to control
Transmitter response to a change of the measured variable.
• Mechanical Assembly. The Transmitter electronics enclosure is constructed of cast
aluminum with an epoxy finish. The materials offered for diaphragms, process
connections, flanges, bolts, etc. vary with the model. The specific material selections for
each Transmitter model are given in Sections 1A through 1C.
•
Fill System. The Transmitter's diaphragm and sensor operate in a sealed fluid system.
These systems are furnished with DC 200 as the fill fluid.
•
Electrical Conduit Port. Two 1/2 inch NPT female ports are provided for electrical
conduit.
2808B
Section 1
INTRODUCTION
Strain gauge, piezo-resistive sensors perform pressure
Introduction / 1-1