INTEGRIstick - Dynamic curvature sensor

The Pulse INTEGRIstick is a unique patented sensor specifically suited for riser fatigue monitoring where response is dynamic bending dominated.

Typical applications include fatigue monitoring in the touch down section of an SCR and the taper joint of a top tensioned riser.

The stick sensor is 19 mm diameter and 500 mm in length and it is attached to the outside surface of a riser. It changes in sympathy with the riser pipe and measures the change in riser curvature in 2 planes allowing local dynamic bending stress to be determined and hence the fatigue damage rate to be calculated.

The INTEGRIstick™ has high accuracy, typically allowing 1 micro-strain resolution (depending on riser pipe diameter). This makes the sensor sensitive enough to capture lowest seastates. This capability is essential for measuring response under day to day current profiles and waves that contribute significantly to damage accumulation.

Uniquely the INTEGRIstick™ is sealed, oil-filled and pressure balanced allowing application at depths up to 3000m. It is manufactured from corrosion resistant materials.

System configuration
The sensor has ultra low power consumption and designed to interface directly to the INTEGRIpod™ for battery-powered standalone or online data logging. The connection between the INTEGRIstick™ and INTEGRIpod™ can be a permanent flange connection, a dry-mate connector or an ROV connector. The connection type will depend on the project specification. The ROV retrievable INTEGRIpod™ using a ROV connector allows the INTEGRIpod™ to be removed and replaced whilst leaving the stick mounted on the riser.

Mounting method
The strain measurement system is compact, ultra lightweight and can be fitted to the riser in a matter of minutes. When fitted with a compact GRP fairing the arrangement provides a highly reliable and robust method for measuring riser bending stresses.