초록 ▼

Flowmeter apparatus and method for obtaining accurate measurement of fluid flow, not only in the turbulent flow range, but also in the laminar and transitional flow ranges by compensation of the meter reading. The meter reading is also compensated for change in viscosity of the fluid flowing through

Flowmeter apparatus and method for obtaining accurate measurement of fluid flow, not only in the turbulent flow range, but also in the laminar and transitional flow ranges by compensation of the meter reading. The meter reading is also compensated for change in viscosity of the fluid flowing through the meter. The compensation for flow range is based on the best-fit straight line approach obtained by matching straight line segments to the quantity versus frequency output curve throughout the laminar and transitional ranges, and compensating the flowmeter reading in accordance with the shape of the straight line segments. The compensation for change in kinematic viscosity of the fluid is added to the flowmeter output in accordance with the temperature-viscosity relationship for the fluid and in accordance with a ratio of compensation factors between the actual fluid and a reference fluid.

대표청구항 ▼

An apparatus for obtaining a measure of fluid flow rate over the laminar, transitional and turbulent flow range comprising: a turbine flowmeter located in a fluid flow line and producing a frequency output signal variable with flow rate; means for comparing said output signal with a constant referen

An apparatus for obtaining a measure of fluid flow rate over the laminar, transitional and turbulent flow range comprising: a turbine flowmeter located in a fluid flow line and producing a frequency output signal variable with flow rate; means for comparing said output signal with a constant reference value to produce a difference signal which is zero throughout the turbulent flow range of the fluid through the flowmeter commencing at frequency (f1); means responsive to said difference signal for producing a compensating signal for compensating said output signal of said flow meter over the laminar and transitional flow ranges for variations from quantities indicated by the straight line function of flow rate versus frequency in the turbulent flow range; and means for combining said compensating signal with said flowmeter output signal to obtain a correct value of flow rate in the laminar and transitional flow ranges.