Abstract: Disclosed is a novel apparatus and method for volumetric dilatometry. A volumetric dilatometer includes an optical displacement sensor and a means for using a gap measurement obtained from the displacement sensor application in an application which requires the measurement of absolute distance and/or displacement. A novel signal-processing algorithm for volumetric dilatometry is also disclosed. The signal-processing algorithm includes a step for recovering the phase information from a spectral signal by taking the Fourier transform of a spectral signal and deriving a sensor gap measurement from the phase information. A micro-translation stage is provided for automated positioning of the optical sensor and automated re-leveling in an out-of-range condition. A heat source is consists of a vertical tube furnace, such as those found in drywell technologies.

Abstract: Disclosed is a novel apparatus and method for volumetric dilatometry. A volumetric dilatometer includes an optical displacement sensor and a means for using a gap measurement obtained from the displacement sensor application in an application which requires the measurement of absolute distance and/or displacement. A novel signal-processing algorithm for volumetric dilatometry is also disclosed. The signal-processing algorithm includes a step for recovering the phase information from a spectral signal by taking the Fourier transform of a spectral signal and deriving a sensor gap measurement from the phase information. A micro-translation stage is provided for automated positioning of the optical sensor and automated re-leveling in an out-of-range condition. A heat source is consists of a vertical tube furnace, such as those found in drywell technologies.

Abstract: A method for calculating a distance from a fiber optic tip of a sensor to a reflective surface by high pass filtering a fringe signal gathered by a spectrometer, calculating a power spectral density of the filtered signal, and using a calibrated distance vs. peak spectral density wavelength curve to determine the measured distance. This fiber optic distance measurement technique can be applied to a variety of sensor types, including, but not limited to, pressure, displacement, temperature, acoustic, pressure, load, and magnetic field sensors.