Advanced Instrumentation Diagnostics to Detect Process Problems

Many of today’s process instruments have advanced diagnostic capabilities that enable predictive maintenance.

It’s safe to say that few of us understand or utilize all of the capabilities that most devices offer. Take smartphones and computers as an example. These devices offer countless capabilities, yet the average user tends to learn the functions needed for everyday life and overlook the rest. In many cases, we may be astonished to discover some function that we have neglected has major benefits.

Similarly, instrumentation engineers in process manufacturing facilities may overlook the capabilities of field instrumentation diagnostics. Although they have been available for many years, diagnostic functions offer several benefits. Diagnostics play a critical role in today’s chemical process industries (CPI), where safety, reliability, and process optimization are critical to an organization’s competitiveness. It may be time for a fresh look at the possibilities to see how much has changed with new and improved capabilities.

Today’s diagnostics cover three main functional areas:

• internal condition monitoring
• process-related functions
• communications.

This article describes the diagnostic capabilities of process instruments using pressure transmitters as an example. This selection is based on the ubiquity of pressure transmitters, as they can measure conventional pressure, differential pressure (DP), fluid flow, and liquid level. In addition, pressure transmitters make up the largest number of instruments for most manufacturing facilities (Figure 1). Other types of instruments and actuators have diagnostic capabilities related to their functions. Much of what is discussed in this article can be extended or adapted to these components.

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▲Figure 1. Pressure transmitters are often the most common instrument in a process plant.