I
NTRODUCTION
1-2
June 1997 Rosemount Analytical 748213-P
Model 755R Oxygen Analyzer
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 instrument, 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.
1.5 ALARM OPTION
The alarm option contains:
•
An alarm circuit incorporating two comparator amplifiers, one each for the
ALARM 1 and ALARM 2 functions. Each amplifier has associated setpoint and
deadband adjustments. Setpoint is adjustable from 1% to 100% of fullscale.
Deadband is adjustable from 1% to 20% of fullscale.
•
An alarm relay assembly, containing two single-pole, double-throw relays (one
each for the ALARM 1 and ALARM 2 contacts). These relays may be used to
drive external, customer-supplied alarm and/or control devices.
1.6 ELECTRICAL OPTIONS
The analyzer is supplied, as ordered, for operation on either 115 VAC, 50/60 Hz or 230
VAC, 50/60 Hz.
1.7 REMOTE RANGE CHANGE OPTION
This option allows the customer to remotely control the recorder scaling. It disables
the internal recorder fullscale range select without affecting the front panel display.
