Marine icing sensor design using capacitive techniques

Abstract

The Marine Icing project, in industrial collaboration with Statoil, explores and develops in-depth research on marine icing phenomena, and the appropriate sensor technology to detect ice accretion in marine and offshore environments. The overall project includes detailed analytical concepts, simulations, and experiments of on and off deck ice accretion activities in the form of wave breakup and droplet freeing phenomena. Part of the project is dedicated to developing appropriate low cost sensors for ice accretion detection in these harsh environments. Proposed sensors should be autonomous and easy to modify. After examining the available ice detecting systems, it was decided to explore capacitive techniques, a concept that have been used in other industrial applications like tilt sensing, liquid level sensing, and accelerometers. However, the capacitive sensing technique has not been explored for marine ice detection and therefore will be developed in this thesis. A capacitive based sensor is simulated, designed, tested, and documented in this thesis. The proposed sensor consists of a copper tracing on a PCB, capacitance to digital converter circuit and a microcontroller. The whole system runs on a simple battery system or powered by a programming cable, depending on the area of deployment. The microcontroller controls the capacitance to digital converter circuit as well as the temperature sensing circuit. Additionally, this research compares the change in capacitance observed with the change in ice thickness; proper sensor calibration is drawn from this result. The system is used to test ice accretion due to fresh and saline water, observation and conclusions are made based on the data obtained. This thesis focuses on developing a technical start up point for capacitive marine ice sensing.