Method and apparatus for measuring a fluid
First Claim
1. A flow meter for measuring a fluid having a temperature, comprising:
- a flow sensor including a sensor tube, a first heater disposed at said sensor tube, a second heater disposed at said sensor tube, and a first temperature sensor in thermal communication with the fluid; and
a circuit for selectively applying power to said first and second heaters to provide said first and second heaters at a temperature a fixed amount above the temperature of the fluid, and for determining a difference in power supplied to said first and second heaters, wherein the power supplied to said first and second heaters is determined from a product of a voltage and a current supplied to each of said first and second heaters.
3 Assignments
0 Petitions
Accused Products
Abstract
A flow sensor including a symmetrical sensor tube for carrying the fluid, first and second heaters symmetrically disposed at the sensor tube, and a first temperature sensor in thermal communication with the fluid. A flow meter including a flow sensor having a sensor tube, a first heater disposed at the sensor tube, a second heater disposed at the sensor tube, and a first temperature sensor in thermal communication with the fluid. The meter also includes a circuit for selectively applying power to the first and second heaters to maintain a temperature difference between a temperature of the first and second heaters and the temperature of the fluid, and for determining a difference in power supplied to the first and second heaters. A method including providing first and second heaters at a temperature a fixed amount above a temperature of the fluid; determining a difference in power supplied to the first and second heaters; and determining a measurement of the fluid from the difference in power supplied to the first and second heaters.
48 Citations
48 Claims
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1. A flow meter for measuring a fluid having a temperature, comprising:
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a flow sensor including a sensor tube, a first heater disposed at said sensor tube, a second heater disposed at said sensor tube, and a first temperature sensor in thermal communication with the fluid; and a circuit for selectively applying power to said first and second heaters to provide said first and second heaters at a temperature a fixed amount above the temperature of the fluid, and for determining a difference in power supplied to said first and second heaters, wherein the power supplied to said first and second heaters is determined from a product of a voltage and a current supplied to each of said first and second heaters. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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40. A method of measuring a fluid having a temperature, comprising:
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determining the temperature of the fluid; providing first and second heaters at a temperature a fixed amount above the temperature; determining a difference in power supplied to the first and second heaters, wherein determining the power supplied to each of the first and second heater includes determining a product of a current and a voltage supplied to each of the first and second heaters; and determining a measurement of the fluid from the difference in power supplied to the first and second heaters. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47, 48)
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Specification