Instruction Manual

Instruction Manual
748213-S
April 2002
Rosemount Analytical Inc. A Division of Emerson Process Management Description and Specifications 1-1
Model 755R
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SECTION 1
DESCRIPTION AND SPECIFICATIONS
1-1 DESCRIPTION
The Model 755R Oxygen Analyzer provides
continuous readout of the oxygen content of a
flowing gas sample. The determination is
based on measurement of the magnetic sus-
ceptibility of the sample gas. Oxygen is
strongly paramagnetic while most other com-
mon gases are weakly diamagnetic.
The instrument provides direct readout of 0 to
100% oxygen concentration on a front panel
digital display. In addition, a field-selectable
voltage output is provided as standard. An
isolated current output of 0 to 20 mA or 4 to
20 mA is obtainable through plug-in of an op-
tional circuit board. Current and voltage out-
puts may be utilized simultaneously if desired.
An alarm option is also available by way of a
relay assembly that mounts at the rear of the
case with a cable that plugs into the Control
Board. Customer connections are available on
this assembly.
The basic electronic circuitry is incorporated
into two master boards designated the Control
Board assembly and the Power Supply Board
assembly. The Control Board has receptacles
that accept optional plug-in current output
board and alarm features.
1-2 RECORDER OUTPUT RANGES
Seven zero-based ranges are available with
the Model 755R: 0 to 1%, 0 to 2.5%, 0 to 5%, 0
to 10%, 0 to 25%, 0 to 50%, and 0 to 100%.
Each range is jumper selectable.
1-3 MOUNTING
The Model 755R is a rack-mounted instru-
ment, standard for a 19-inch relay rack (Refer
to IEC Standard, Publication 297-1, 1986).
1-4 ISOLATED CURRENT OUTPUT OPTION
An isolated current output is obtainable by
using an optional current output board, either
during factory assembly or subsequently in
the field. The board provides ranges of 0 to 20
or 4 to 20 mA into a maximum resistive load
of 1000 ohms.
Figure 1-1. Model 755R Oxygen Analyzer – Front Panel