A new calibration set-up was designed and assembled, and a comprehensive sensitivity analysis was conducted to investigate factors that may affect the calibration of the effective distance of an optical fibre particle velocity probe. It is shown that the glass window has the most significant impact on the calibration result. The optical fibre probe was then applied to measure local particle velocities and solid fractions inside a half and a full circular conical spouted bed. It is found that the overall particle velocity profiles, as well as the shapes of the spout and fountain are quite similar in both columns.