Method and apparatus for measuring fluid flow
OwnerDonald F. Wisemaninventor
Life of this patent
Estimating the term…
Abstract
A method and apparatus for the measurement of fluid flow through a conduit comprises determining, from one or more measuring elements, a first value related to the velocity of fluid flowing through the conduit. A second value, related to the temperature of fluid ambient to the conduit, is also determined. The method further includes establishing a third value related to the physical configuration of the measuring means. The first, second and third values are then used to calculate a power dissipation factor of the measuring means to be used in calculating a velocity indication which substantially eliminates errors due to changes in ambient temperature and caused by velocity cooling within the conduit.
Claims16
An apparatus for the measurement of fluid flow through a conduit comprising:
- at least one thermally sensitive electrical resistor serving as a measuring resistor for location within said conduit and exposure to the flow of fluid therethrough, the resistance value of said measuring resistor being a function of flow in said conduit;
- a thermally sensitive electrical resistor serving as a reference resistor for association with said conduit, the resistance value of said reference resistor being a function of temperature of fluid ambient to said conduit and being substantially uninfluenced by the flow in said conduit;
- electrical circuit means for determining the voltage across said measuring resistor and the voltage across said reference resistor and for using said voltages in the calculation of a value of velocity of fluid flow through said conduit;
- and
- means for calculating the velocity of fluid flow in the conduit in accordance with an equation which uses a numerical value equal to a power dissipation factor of said measuring resistor, which power dissipation factor itself is calculated, with said means for calculating, using a series of pre-calculated constants related to the electrical characteristics of said measuring resistor.
A method for the measurement of fluid flow through a conduit comprising:
- determining from measuring means a first value related to the velocity of fluid flowing through said conduit and a second value related to the temperature of fluid ambient to said conduit;
- determining a third value related to a power dissipation factor of said measuring means wherein said third value is numerically equal to said power dissipation factor and is calculated using stored pre-calculated constants relating to the electrical characteristics of said measuring means;
- establishing an equation related to the physical configuration of said measuring means;
- and
- using said first, second and third values and said equation to calculate a velocity indication which substantially eliminates errors due to changes in ambient temperature and caused by velocity cooling within said conduit.
An apparatus for the measurement of fluid flow through a conduit comprising:
- means for measuring a first value related to the velocity of fluid flowing through said conduit and a second value related to the temperature of fluid ambient to said conduit;
- means for determining a third value related to a power dissipation factor of said means for measuring wherein said third value is numerically equal to said power dissipation factor and is determined using pre-calculated constants relating to the electrical characteristics of said means for measuring;
- means for establishing an equation related to the physical configuration of said means for measuring;
- and
- means for calculating, using said first, second and third values and said equation, a velocity indication which substantially eliminating errors due to changes in ambient temperature and caused by velocity cooling within said conduit.
Dependencies are inferred from the claim text.