Method and apparatus for electronic compensation of erroneous readings caused by resonance in a capacitive pressure transducer
First Claim
1. A method for measuring pressure using a capacitive pressure transducer (1) and determining the capacitance of the capacitive pressure transducer (1) by AC measurement, wherein erroneous readings due to resonance in the capacitive pressure transducer (1) are electronically compensated, the method comprising:
- artificially causing the capacitive pressure transducer (1) to resonate,measuring an error (Δ
Us) caused by the resonance of the transducer (1) in a measurement circuit, andfeeding a compensation signal (Ures) into the measurement circuit which completely eliminates the erroneous reading.
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Abstract
A method for electronic compensation of erroneous readings is based on the observation that a sensor serving as a transducer is caused to resonate. The erroneous reading caused by the resonance is measured and a compensation signal is feedback into the measurement element, the signal being essentially unfiltered. An apparatus uses error detection and compensation circuits whose upper barrier frequency are above the resonance frequency of the transducer for detecting an error signal caused by resonance in the transducer and for generating a compensation signal for feeding into the detector sensor.
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Citations
12 Claims
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1. A method for measuring pressure using a capacitive pressure transducer (1) and determining the capacitance of the capacitive pressure transducer (1) by AC measurement, wherein erroneous readings due to resonance in the capacitive pressure transducer (1) are electronically compensated, the method comprising:
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artificially causing the capacitive pressure transducer (1) to resonate, measuring an error (Δ
Us) caused by the resonance of the transducer (1) in a measurement circuit, andfeeding a compensation signal (Ures) into the measurement circuit which completely eliminates the erroneous reading. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A pressure measuring device comprising:
- a capacitive pressure transducer (1) and detector means (SW1, F1, F2) for simultaneous detection of the position of a sensing membrane (2) of the capacitive pressure transducer (1) and of pressure, and means for electronic compensation of erroneous readings caused by resonance in the capacitive pressure transducer (1) including error detection and compensation means (F3, F4, F5) having an upper barrier frequency above the resonance frequency of the transducer (1) for detecting the erroneous reading caused by resonance in the capacitive pressure transducer (1) and for generating a compensation signal (Ures) for feeding into the detector means (SW1, F1, F2).
- View Dependent Claims (11, 12)
Specification