Mass flow meter or controller with inclination sensor
First Claim
1. A mass flow meter having a fluid inlet and a fluid outlet, comprising:
- a thermal mass flow sensor to provide a first electrical signal indicative of a mass flow rate of a fluid flowing between the fluid inlet and the fluid outlet, the thermal mass flow sensor having a sensor inlet portion fluidly connected to the fluid inlet, a sensor outlet portion fluidly connected to the fluid outlet, and a sensor measuring portion disposed between and fluidly connected to the sensor inlet portion and the sensor outlet portion;
at least one inclination sensor to provide at least one second electrical signal indicative of an angle of inclination of at least one of the sensor inlet portion, the sensor outlet portion, and the sensor measuring portion relative to at least one reference axis; and
a controller, to receive the first electrical signal and the at least one second electrical signal, calculate a correction factor based upon the at least one second electrical signal, and apply the correction factor to the first electrical signal to provide a third electrical signal indicative of the mass flow rate of the fluid flowing between the fluid inlet and the fluid outlet that is compensated for the angle of inclination of the at least one of the sensor inlet portion, the sensor outlet portion, and the sensor measuring portion relative to the at least one reference axis.
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Accused Products
Abstract
A thermal mass flow meter associated with an inclination sensor that detects an angle of inclination of at least one portion of a thermal mass flow sensor relative to at least one reference axis. Based upon the detected angle of inclination, the output signal of the mass flow meter that is indicative of the mass flow rate of fluid through the sensor may be compensated to account for any inaccuracies relating to the orientation in which the mass flow meter is installed. Inaccuracies for which compensation may be provided include thermal siphoning effects and fluid buoyancy effects. By compensating for such inaccuracies, the mass flow meter may be used in any orientation, and/or may be used in non-inertial (e.g., accelerating) environments. The flow meter may be used as a stand alone device, or incorporated in a thermal mass flow controller.
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Citations
38 Claims
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1. A mass flow meter having a fluid inlet and a fluid outlet, comprising:
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a thermal mass flow sensor to provide a first electrical signal indicative of a mass flow rate of a fluid flowing between the fluid inlet and the fluid outlet, the thermal mass flow sensor having a sensor inlet portion fluidly connected to the fluid inlet, a sensor outlet portion fluidly connected to the fluid outlet, and a sensor measuring portion disposed between and fluidly connected to the sensor inlet portion and the sensor outlet portion; at least one inclination sensor to provide at least one second electrical signal indicative of an angle of inclination of at least one of the sensor inlet portion, the sensor outlet portion, and the sensor measuring portion relative to at least one reference axis; and a controller, to receive the first electrical signal and the at least one second electrical signal, calculate a correction factor based upon the at least one second electrical signal, and apply the correction factor to the first electrical signal to provide a third electrical signal indicative of the mass flow rate of the fluid flowing between the fluid inlet and the fluid outlet that is compensated for the angle of inclination of the at least one of the sensor inlet portion, the sensor outlet portion, and the sensor measuring portion relative to the at least one reference axis. - 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)
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28. A method of determining a mass flow rate of a fluid flowing in a fluid flow path that includes a sensor flow path having a sensor inlet portion, a sensor outlet portion, and a sensor measuring portion, the method comprising acts of:
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determining a flow rate of the fluid flowing in the sensor measuring portion of the sensor flow path; determining an angle of inclination of at least one of the sensor inlet portion, the sensor outlet portion, and the sensor measuring portion relative to at least one reference axis; calculating at least one correction factor based upon the determined angle of inclination of the at least one of the sensor inlet portion, the sensor outlet portion, and the sensor measuring portion relative to at least one reference axis; and determining the mass flow rate of the fluid flowing in the fluid flow path based upon the determined flow rate of the fluid flowing in the sensor measuring portion of the sensor flow path and the at least one calculated correction factor. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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Specification