| 摘要 |
Apparatus and methods for detecting and correcting various fault conditions in an operating Coriolis effect mass flowmeter. The apparatus of the present invention receives information from an operating Coriolis mass flowmeter and compares the information to threshold signatures representing various fault conditions. When a fault condition is detected, output signals are applied to inform an operator and to control the mass flow rate through the flowmeter to correct the fault condition. Specifically, the methods of the present invention detect the presence of a crack in the flow tubes and stop the flow of material to prevent release of the material through a cracked flow tubes. Other methods of the present invention detect the void fraction of material flowing through the flow tubes, compute a corrected actual mass flow rate, and control the mass flow rate through the flowmeter to compensate for the effects of the void fraction. Signature information relating to threshold values for measured frequency, drive power, temperature and mass flow of the operating flowmeter as well as the slope and curvature of changes in each measured operating parameter are stored in memory within the fault detection apparatus of the present invention.
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