Abstract
CRIEPI has developed the fiber-optic sensor that can be applied up to 600℃ and measurement system. However, reliability of conventional heat-resistant sensor was poor due to brittleness of fiber and structural design. In this report, improvement of heat-resistant sensor was successfully carried out and the sensor could be applied up to 650℃. Minimum detectable size of microcrack using the fiber-optic sensors was evaluated based on FEM simulation of elastic wave propagation. It was estimated that microcracks radius of above 2mm could be detected using the heat-resistant sensor on an actual steam piping.
