Instruction Manual

IM-106-880, Rev 1.0 January 2007

OCX 8800

The equipment measures oxygen percentage by reading the voltage developed across a heated electrochemical cell, which consists of a small yttria-stabilized, zirconia disc. Both sides of the disc are coated with porous metal electrodes. When operated at the proper temperature, the millivolt output of the cell is given by the following Nernst equation:

EMF = KT log10 (P1/P2) + C

Where:

1.P2 is the partial pressure of the oxygen in the measured gas on one side of the cell.

2.P1 is the partial pressure of the oxygen in the reference air on the opposite side of the cell.

3.T is the absolute temperature.

4.C is the cell constant.

5.K is an arithmetic constant.

NOTE

For best results, use clean, dry instrument air (20.95% oxygen) as the reference air.

When the cell is at operating temperature and there are unequal oxygen concentrations across the cell, oxygen ions will travel from the high oxygen partial pressure side to the low oxygen partial pressure side of the cell. The resulting logarithmic output voltage is approximately 50 mV per decade. The output is proportional to the inverse logarithm of the oxygen concentration. Therefore, the output signal increases as the oxygen concentration of the sample gas decreases. This characteristic enables the OCX 8800 to provide exceptional sensitivity at low oxygen concentrations.

The OCX 8800 measures net oxygen concentration in the presence of all the products of combustion, including water vapor. Therefore, it may be considered an analysis on a "wet" basis. In comparison with older methods, such as the portable apparatus, which provides an analysis on a "dry" gas basis, the "wet" analysis will, in general, indicate a lower percentage of oxygen. The difference will be proportional to the water content of the sampled gas stream.

The OCX 8800 combustibles sensor is a catalytic sensor consisting of two Resistance Devices (RTD). One RTD is the reference element covered with an inert coating. The other RTD element is active, coated with a catalyst. As the sample gases flow by the sensor, the combustible gases oxidize on the surface of the active element. The oxidation that occurs produces heat and a temperature rise in the active element. The temperature difference produces a resistance relationship between the two elements that is directly proportional to the concentration of combustibles in the sample gases.

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Emerson 8800 instruction manual Ocx
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8800 specifications

The Emerson 8800, a pivotal instrument in industrial automation, stands out for its robust features and cutting-edge technologies. Designed to enhance process efficiency and reliability, this device is integral to numerous industries, including oil and gas, chemical, and power generation.

One of the standout features of the Emerson 8800 is its advanced control capabilities. It incorporates a highly flexible control architecture that supports a wide variety of control schemes. This adaptability allows engineers to implement customized solutions tailored to specific process requirements. Additionally, the 8800 series includes integrated predictive diagnostics that continually monitor system performance, alerting operators to potential issues before they escalate into serious problems.

The technology powering the Emerson 8800 is equally impressive. Equipped with state-of-the-art microprocessors, it can handle complex calculations and data processing with remarkable speed and accuracy. The device supports multiple communication protocols, including Foundation Fieldbus, HART, and Modbus. This flexibility ensures seamless integration with existing systems, thereby enhancing data sharing and communication between devices.

Moreover, the Emerson 8800 features a user-friendly interface that simplifies operation and monitoring. The intuitive display allows operators to easily navigate through various settings and real-time data, promoting better decision-making and faster response times. This ergonomic design enhances usability in high-pressure environments, ultimately contributing to improved safety and operational efficiency.

Another key characteristic of the Emerson 8800 is its durability and reliability. Built to withstand the rigors of industrial environments, the device boasts a robust enclosure, ensuring protection against dust, moisture, and extreme temperatures. This reliability minimizes the risk of downtime, making it a cost-effective choice for industries where uptime is critical.

In summary, the Emerson 8800 emerges as a powerhouse in the realm of industrial automation. With its advanced control systems, diverse communication capabilities, user-friendly interface, and rugged design, it embodies efficiency and reliability. As industries continue to evolve, the Emerson 8800 stands ready to meet the challenges of modern automation, driving innovation and productivity in complex environments.
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