| Summary: | <p>Validating real-time measurements from a sensor/instrument is a multifaceted challenge. One goal is the provision of a dynamic uncertainty analysis, ideally incorporating the influence of instrument faults and the local environment. Such an analysis requires a broader model of instrument behaviour, accommodating non-ideal operational conditions. It may also require the analysis of a wider range of transducer data than when ideal, fault-free operation is assumed.</p>
<p>A companion presentation describes an ultra-precise Fast Fourier Transform (FFT) technique. In this presentation, the technique is applied to a Coriolis mass flow meter, a resonant sensor with rich spectral characteristics. Typically, the meter is driven in a single natural mode of mechanical vibration; the frequency of this mode varies with fluid density, while the flow rate and density calibration coefficients assume a fixed frequency ratio to an adjacent vibration mode.</p>
<p>A prototype Coriolis meter can operate in two modes of vibration simultaneously. The new FFT technique exhibits high precision (mode frequencies from the two independent vibration sensors agree by up to 10<sup>−8</sup> Hz), allowing precise tracking of the true frequency ratio for on-line calibration and measurement validation. Additional transducer signal components, such as mains noise and external vibration, may be identified and monitored.</p>
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