Macro Sensors designs new LVDT to monitor structural integrity

Offshore staff

PENNSAUKEN, New Jersey -- Macro Sensors has designed a pressure-balanced, oil-filled, and double bellows-sealed LVDT assembly to enhance the reliability of multiple redundant LVDT-based extensometers mounted longitudinally around the circumference of the structural member to monitor structural integrity.

The LVDTs enabled measurement of the extension of the structural members to a fraction of a microstrain. Macro Sensors designed its LVDT assembly from 316 SS and Inconel 625 for pressure and corrosion resistance.

Macro Sensors' LVDTs also resolved the problem of getting a useful signal back to the surface, even in great water depths, for monitoring, recording, and controlling thrusters and ballast transfer pumps. The extensometer housing can be outfitted with a variety of mechanical terminations to facilitate connection to the structural members.

To minimize the number of pressure-sealed connections, a 4-20ma loop-powered I/O was used, which the customer converted to a RS485 digital signal for transmission to the surface. The two-wire I/O also minimized any noise going to the digital converter that was contained in a high-pressure sealed bottle located nearby.

01/16/2009