Current measurement instrumentation sensors for industrial applications: Requirements, problems, and proposed solutions for the next generation of instruments

Industry commonly uses current measurement data to properly design and safely install marine structures. The ocean engineer's information requirements emphasize maximum current velocities and durations, with less stringent requirements placed on the data's absolute accuracy and resolution. While reduced accuracy is acceptable, the data acquired must truly represent the ocean dynamics. In this type of application, the reliability and system cost, not sensor accuracy, become the trade-off considerations by which the current sensor components of a system are selected. This reliability is expressed not only in system design but also in instrument ruggedness, ability to detect failures before installation, component reliability and commonality, and ease of servicing at sea. Our experiences have shown major deficiencies in the areas of power supplies, tape transport reliability and commonality, and errors derived in the encoding and translation process. All of the deficiencies cause errors that may not be entirely evident without rigid data processing controls.