Flow sensor and method of measuring a flow
AssigneeFresenius Medical Care Deutschland GmbH
InventorsDejan Nikolic, Alexander Heide
Life of this patent
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Abstract
The present invention relates to a flow sensor for measuring a flow difference having at least two measurement chambers through which fluid is conductible; at least one means for producing a magnetic field for charge separation in a fluid flowing through the at least two measurement chambers; and at least one means for measuring an electric potential in the fluid flowing through the at least two measurement chambers, with the at least two measurement chambers being arranged such that they are run through by the same magnetic field line of the magnetic field for charge separation.
Claims11
A flow sensor for measuring a flow difference comprising:
- at least two measurement chambers through which fluid is conductible;
- at least one means for producing a magnetic field for charge separation in a fluid flowing through the at least two measurement chambers, the magnetic field for charge separation having magnetic field lines;
- at least one means for measuring an electric potential in the fluid flowing through the at least two measurement chambers;
- a temperature sensor for measuring the temperature of a fluid flowing through the at least two measurement chambers, the temperature sensor being configured to detect the temperature of the fluid in the flow sensor;
- and
- an evaluation device, wherein
- the at least two measurement chambers are arranged such that they are run through by the same magnetic field lines of the magnetic field for charge separation, and
- the evaluation device is configured to determine respective flow measurement values of fluid flowing through the at least two measurement chambers, correct the respective flow measurement values based on the temperature of the fluid in the flow sensor, which is measured by the temperature sensor, and determine a differential flow measurement of the fluid flowing through the at least two measurement chambers by offsetting the corrected flow measurement values.
A method for determining a differential flow measurement of a fluid flowing through two measurement chambers, comprising the steps of:
- conducting fluid through a first measurement chamber and through a second measurement chamber of a flow sensor;
- producing a magnetic field for charge separation in the fluid in the first measurement chamber and in the second measurement chamber;
- measuring an electric potential in the fluid flowing through the first measurement chamber;
- measuring an electric potential in the fluid flowing through the second measurement chamber, wherein the magnetic field for charge separation is produced such that the same magnetic field lines of the magnetic field for charge separation run through both the first measurement chamber and the second measurement chamber;
- determining a first flow measurement value for the flow of fluid flowing through the first measurement chamber, based on the measured electrical potential of the fluid flowing through the first measurement chamber;
- determining a second flow measurement value for the flow of fluid flowing through the second measurement chamber, based on the measured electrical potential of the fluid flowing through the second measurement chamber;
- detecting the temperature of the fluid, in the flow sensor, with a temperature sensor integrated in the flow sensor;
- correcting the first flow measurement value and the second flow measurement value, based on the temperature detected in the flow sensor, to form a corrected first flow measurement value and a corrected second flow measurement value;
- and
- determining a differential flow measurement of the fluid flowing through the first and second measurement chambers by offsetting the corrected first flow measurement value with the corrected second flow measurement value.
Dependencies are inferred from the claim text.