An intrinsic exposed core optical fiber sensor as a quantitative surface crystallization monitoring sensor

An intrinsic exposed core optical fiber sensors has been described that is capable of monitoring surface crystallization, also known as scale formation. The optical fiber sensor is a more reliable sensor of scale growth than other scale sensing methods, such as turbidity measurement, due to its ability to discriminate between bulk and surface crystallization. When the sensor was subjected to the same crystal growth conditions as a stainless steel surface, the optical fiber sensor showed the capability to follow the scale formation on the scale affected stainless steel surface.