2808B
Introduction / 1-1
Section 1
INTRODUCTION
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.
Strain gauge, piezo-resistive sensors perform pressure
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.
Summary of Contents for Bristol 2808 Series
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Page 14: ...1 2 Introduction 2808B Figure 1 1 2808 XXB Transmitters ...
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Page 32: ...1B 2 DP Transmitters 2808B Figure 1B 1 Model 2808 35B Figure 1B 2 Transmitter Assemblies ...
Page 40: ...1B 10 DP Transmitters 2808B Figure 1B 6 Transmitter Housing Rotation Diagram ...
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Page 57: ...2808B Calibration 3 3 Figure 3 2 Calibration Adjustments ...
Page 60: ...3 6 Calibration 2808B TABLE 3 A COARSE ZERO SWITCH SETTINGS Elevation ...
Page 61: ...2808B Calibration 3 7 TABLE 3 B COARSE ZERO SWITCH SETTINGS Suppression ...
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Page 68: ...4 2 Service 2808B Figure 4 1 Using Internal TEST Terminals to Measure Current ...
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