Emerson 8800 instruction manual System Configuration, System Features

OCX 8800

Instruction Manual

IM-106-880, Rev 1.0 January 2007

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 and sensor housings are integrally mounted.

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 O2 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.

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