Emerson OCX 8800 Oxygen Equipment User Manual


 
Instruction Manual
IM-106-880, Rev 1.0
January 2007
OCX 8800
1-4
The catalyst is specifically designed to detect carbon monoxide (CO), but the
sensor responds to other combustible gases. The sensor is calibrated using
CO, thus the output should be expressed in terms of CO. However, since the
sensor detects other combustible gases, the output cannot just be labeled
CO. The response of the sensor to other combustible gases gives an output
that is equivalent to the sensor detecting CO. The term COe is used in this
manual to describe the sensor output. This term indicates that the sensor is
calibrated in terms of CO, and that the sensor output is equivalent to CO but
not specific to CO.
Dilution air is provided to the COe sensor to ensure there is adequate oxygen
to fully oxidize any combustible gases regardless of the concentration of
oxygen in the process.
System Configuration
Transmitters are available in four lengths, giving the user the flexibility to use
a penetration appropriate to the size of the stack or duct. The length options
are 18 in. (457 mm), 3 ft (0.91 m), 6 ft (1.83 m), or 9 ft (2.7 m). Probes are
available in three material options, 316L stainless steel, inconel 600, and
ceramic to accommodate higher temperatures.
The electronics are contained in a separate housing from the sensors. The
electronics housing may be mounted up to 150 feet away from the sensor
housing.
The electronics control both sensor temperatures and provide individual 4-20
mA isolated outputs that are proportional to the measured oxygen and
combustibles concentrations. The power supply can accept voltages of 100 to
240 VAC and 50 to 60 Hz. The electronics accepts millivolt signals generated
by the sensors and produces the outputs to be used by remotely connected
devices. The outputs are isolated 4-20 mA linearized currents. Refer to
Section 3, Configuration and Startup for specific instructions upon initial
power up.
System Features
1. The O
2
cell output voltage and sensitivity increase as the oxygen
concentration decreases.
2. HART communication is standard. To use the HART capability, you
must have either:
a. HART Model 275/375 Communicator.
b. AMS software for the PC.
3. Oxygen cell and heater/thermocouple assembly are field replaceable.
4. Electronics are automatically configured for line voltages from 100 to
240 VAC.