Strain gage sensor with integral temperature signal
First Claim
1. A pressure sensor comprising:
- a resistive bridge circuit having output terminals for providing a pressure output signal and power terminals for receiving power;
power supply means for providing power to the resistive bridge circuit at a substantially constant voltage across the power terminals such that temperature caused variations in the resistance of the bridge circuit are reflected in the current flowing through the resistive bridge circuit;
a resistive element having a first end electrically coupled to the bridge circuit and having a second end electrically coupled to the power supply to carry at least a known portion of the current through the bridge circuit; and
a first amplifier electrically coupled to the resistive element for amplifying the voltage drop across the resistive element to provide a temperature output signal.
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Accused Products
Abstract
A strain gage pressure sensor having a resistive bridge circuit from which is measured both the applied pressure and the temperature of the pressure sensor. A constant voltage is provided across the bridge circuit such that any temperature caused changes in the resistance of the bridge circuit are reflected in the flow of a bridge current through the bridge circuit. A sense resistor is electrically coupled to the bridge circuit such that any change in the bridge current causes a change in the voltage drop across the sense resistor. The voltage drop and the pressure output signal are digitized and suitably processed resulting in a highly accurate, corrected pressure output for use with suitable pressure instrumentation.
53 Citations
12 Claims
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1. A pressure sensor comprising:
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a resistive bridge circuit having output terminals for providing a pressure output signal and power terminals for receiving power; power supply means for providing power to the resistive bridge circuit at a substantially constant voltage across the power terminals such that temperature caused variations in the resistance of the bridge circuit are reflected in the current flowing through the resistive bridge circuit; a resistive element having a first end electrically coupled to the bridge circuit and having a second end electrically coupled to the power supply to carry at least a known portion of the current through the bridge circuit; and a first amplifier electrically coupled to the resistive element for amplifying the voltage drop across the resistive element to provide a temperature output signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for measuring the temperature of a pressure sensor having a resistive bridge circuit for providing a pressure output signal and having a power source for supplying a current to flow through power terminals of the bridge circuit, the method comprising the steps of:
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providing a resistive element coupled between the power source and the resistive bridge circuit to carry at least a known portion of the current flowing through the bridge circuit; maintaining a substantially constant voltage across the power terminals such that temperature caused variations in the resistance of the bridge circuit are reflected in the current flowing through the resistive bridge circuit; and measuring the voltage drop across the resistive element. - View Dependent Claims (11, 12)
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Specification