Method and device for determining a flow rate
AssigneeSensirion AG
InventorsAndreas Rüegg, Nicolas Moeller
Life of this patent
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Abstract
In a method of determining a flow rate of a flow of a fluid of interest in a fluidic system, a raw flow rate signal (Qsensor) is determined using a flow rate sensor. The raw flow rate signal is corrected using a flow rate correction function (Δ) to obtain a corrected flow rate signal (Qsensor,corr). The flow rate correction compensates for a flow rate signal error that is caused by integration of the flow rate sensor into the fluidic system. It is based on a reference correction function (δ) that is indicative of a flow rate signal error for a flow of a reference fluid due to the integration of the flow rate sensor into the fluidic system.
Claims18
A method of determining a flow rate of a flow of a fluid of interest in a fluidic system, the method comprising the steps of:
- determining a raw flow rate signal for the flow of the fluid of interest in the fluidic system, using a flow rate sensor that is integrated into the fluidic system;
- correcting the raw flow rate signal using a flow rate correction function to obtain a corrected flow rate signal, the flow rate correction function compensating for a flow rate signal error that is caused by integration of the flow rate sensor into the fluidic system, the flow rate correction function being based on a reference correction function that is indicative of a flow rate signal error for a flow of a reference fluid due to said integration;
- and
- outputting the corrected flow rate signal,
- wherein correcting the raw flow rate signal comprises:
- applying a rescaling operation to the raw flow rate signal, using a flow rate rescaling factor that reflects a deviation of a kinematic viscosity of the fluid of interest from a kinematic viscosity of the reference fluid, to obtain a rescaled flow rate signal;
- evaluating the reference correction function for the rescaled flow rate signal;
- applying an inverse rescaling operation to the result of said evaluation to obtain a value of the flow rate correction function;
- and
- correcting the raw flow rate signal using the thus-obtained value of the flow rate correction function.
A flow measurement device for determining a flow rate of a flow of a fluid of interest in a fluidic system, the flow measurement device comprising:
- a flow rate sensor that is integrated into the fluidic system, the flow rate sensor being configured to determine a raw flow rate signal for the flow of the fluid of interest in the fluidic system;
- and
- electronic circuitry configured to carry out the steps of:
- correcting the raw flow rate signal using a flow rate correction function to obtain a corrected flow rate signal, the flow rate correction function compensating for a flow rate signal error that is caused by integration of the flow rate sensor into the fluidic system, the flow rate correction function being based on a reference correction function that is indicative of a flow rate signal error for a flow of a reference fluid due to said integration;
- and
- outputting the corrected flow rate signal,
- wherein the electronic circuitry is configured to correct the raw flow rate signal by:
- applying a rescaling operation to the raw flow rate signal, using a flow rate rescaling factor that reflects a deviation of a kinematic viscosity of the fluid of interest from a kinematic viscosity of the reference fluid, to obtain a rescaled flow rate signal;
- evaluating the reference correction function for the rescaled flow rate signal;
- applying an inverse rescaling operation to the result of said evaluation to obtain a value of the flow rate correction function;
- and
- correcting the raw flow rate signal using the thus-obtained value of the flow rate correction function.
Dependencies are inferred from the claim text.