Progress in the application of exposed core, optical fibre sensors for detecting and monitoring surface crystallization processes

Abstract

Intrinsic Exposed Core Optical Fibre Sensors (IECOFS) based on step-index, silica fibres have been used to monitor surface crystallization processes. When applied to scale (CaCO₃) detection, the sensor is fully recoverable; requiring only immersion in a solution of dilute HCl. Unlike conventional scale sensors, the IECOFS responds only to heterogenous (surface) crystal growth and the optical response correlates to several crystal growth processes, offering a tool for monitoring surface crystal growth kinetics. Kinetic parameters extracted from the IECOFS response profiles are similar to those obtained from surface crystal growth on stainless steel surfaces indicating the potential for IECOFS as a sensor of scale formation in industrial processes.