Transducer having redundant pressure sensors
First Claim
1. A pressure transducer comprising:
- a fluid pressure sensor comprising a first variable pressure sensor for providing an electrical output as a function of a differential fluid pressure, the first and second variable sensors being located in proximity to each other and in communication with the differential fluid pressure, the first variable pressure sensor being substantially identical to the second variable pressure sensor;
a conditioning circuit for generating a first frequency-based signal whose frequency is a function of the electrical output of the first variable sensor and a second frequency-based signal whose frequency is a function of the electrical output of the second variable sensor; and
means for determining whether the difference between the first signal and the second signal is within a preselected range.
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Accused Products
Abstract
A pressure transducer having a redundant fluid pressure sensor can be used to determine if the pressure transducer needs to be recalibrated. The pressure transducer comprises a fluid pressure sensor for measuring differential pressure. The fluid pressure sensor includes a pair of substantially identical pressure sensors for providing a variable electrical output as a function of a differential fluid pressure and a reference sensor for providing an electrical output independent of the differential fluid pressure. A conditioning circuit is provided for generating a frequency-based signal whose frequency is a function of the electrical output for each fluid pressure sensor. The electrical output of the first and second pressure sensors can be compared to determine whether the pressure transducer needs to be calibrated. In one embodiment, the pressure sensors comprise variable capacitors. The first and second capacitors each have one fixed plate and one movable plate responsive to differential fluid pressure across the movable plate. The reference capacitor has two fixed plates. The first variable, second variable, and reference capacitors are all located in proximity to one another and in communication with the differential fluid pressure. The pressure transducer also includes a switching network connected to the capacitors for selectable connecting at least one of the capacitors to an electronic circuit.
86 Citations
7 Claims
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1. A pressure transducer comprising:
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a fluid pressure sensor comprising a first variable pressure sensor for providing an electrical output as a function of a differential fluid pressure, the first and second variable sensors being located in proximity to each other and in communication with the differential fluid pressure, the first variable pressure sensor being substantially identical to the second variable pressure sensor; a conditioning circuit for generating a first frequency-based signal whose frequency is a function of the electrical output of the first variable sensor and a second frequency-based signal whose frequency is a function of the electrical output of the second variable sensor; and means for determining whether the difference between the first signal and the second signal is within a preselected range. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification