Model 755R

Instruction Manual

748213-S April 2002

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 susceptibility of the sample gas. Oxygen is strongly paramagnetic while most other common 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 optional circuit board. Current and voltage outputs 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.

Digital Display

%O2

ZEROSPAN

Rosemount Anal

Model 755R

Zero Control Span Control

Figure 1-1. Model 755R Oxygen Analyzer – Front Panel

Rosemount Analytical Inc. A Division of Emerson Process Management

Description and Specifications

1-1