High precision ultrasonic corrosion rate monitoring

A process for precisely measuring a thickness of a sound conducting material where the process comprises:

• a) installing an ultrasonic sensor to a location of the sound conducting material where the ultrasonic sensor includes an ultrasonic source disposed to provide an ultrasonic pulse into the material, an ultrasonic receiver disposed to receive reflections of the ultrasonic pulse from the opposite side of the material, a temperature sensor and analytical circuitry to receive and collect temperature data from the temperature sensor and waveform data from the receiver;
• b) measuring the temperature of the material;
• c) emitting a series of pulses from the ultrasonic source into the material;
• d) receiving at least a first and second reflection of each pulse from the material that has crossed the thickness of the material with a receiver to create a wave and collecting the waveforms into a Sample Collection;
• e) aligning the waveforms within the Sample Collection;
• f) averaging the set of aligned waveforms within the Sample Collection to create a Representative Waveform for the Sample Collection;
• g) identifying at least first and second echo sets within the Representative Waveform representing the first reflection from the material and second reflection from the material, respectively;
• h) transforming each backwall echo using a Discrete Fourier Transform;
• i) determining extrema and inflection points of each transformed backwall echo by performing an Inverse Discrete Fourier Transform;
• j) averaging all or some of the extrema and inflection points of each backwall echo to calculate a representative location of the backwall echo;
• and
• k) determining the thickness of the material based on the precise time for an ultrasonic sound wave to travel through the material.