INTEGRIcollar - Subsea strain sensor

The INTEGRIcollar is a strain sensor for measuring axial and bending stresses of a pipe structures.

It uses the proven and robust displacement sensor technology widely used in the industries. The typical application for includes riser air can up-thrust tension measurement, drilling riser tension measurement and tendon tension measurement.

System configuration
The device is attached to the pipe with two rigid collars that are securely installed around the pipe. Four linear displacement sensors are installed between the collars, allowing the pipe axial strain to be measured. The sensors require tiny force to operate, hence they will not impose heavy load to the collars.
The INTEGRIcollar can be interfaced permanently to the Pulse standard data logging pods for standalone or online recording operations. The device may be also connected to an ROV retrievable using a wet mate ROV connection allowing the logger data to be removed and replaced whilst leaving the INTEGRIcollar connected to the structure.
The device relies on the high accuracy, stability and robustness of the non-contact displacement sensors, which are extensively qualified in marine applications. The sensors are hermitically sealed in corrosion resistant alloy materials and are rated to 3000 meters underwater. The robust design coupled with pressure-balanced oil-filling technologies ensures that the can reliably operate for many years without intervention.

Mounting methods
The two halves of the collars of the can be clamped to the riser to anchor themselves to the structure pipe securely. The collars are made from corrosion resistant steel with cathodic protection or coating. The displacement sensor modules are fitted between the two collars. The collars may be also welded to the structure if it is allowed. Forged flanges or bossed collars may also be used if it is preferred. The data logger pods are mounted on the riser using diver or ROV installable brackets.