A method for determining an estimated flow rate of fluid flow in a pump comprises: obtaining measurements of the pressure and temperature of fluid at the intake to the pump, the pressure and temperature of the fluid at the discharge from the pump, and the electrical power supplied to the pump; determining values representing either the density of the fluid and the specific heat capacity of the fluid, or the specific fluid enthalpy based on measurements and/or historical data; and calculating an estimated efficiency of the pump and an estimated flow rate of the fluid based on the measured electrical power, the measured temperatures, the measured pressures, the determined value for density and the determined value for specific heat capacity or the determined value for specific fluid enthalpy.

A method for determining an airflow volume through an air filter is presented. A negative pressure is created within a system housing of an air handling system. Particulate matter is filtered on a filter media of an air filter. A displaceable baffle is progressively moved baffle in proportion to an accumulation of particulate matter on the filter media, wherein the displaceable baffle is movably mounted within a bypass conduit of an airflow sensor device. An output voltage is identified from a magnetic field sensor, wherein the output voltage is proportional to a magnetic flux density of a magnetic field from an actuation magnet mounted on the displaceable baffle. A position of the displaceable baffle is determined based on the output voltage generated by the magnetic field sensor. An accumulation of particulate matter on the filter media is determined based on the position of the displaceable baffle.

A method for determining an airflow volume through an air filter is presented. A negative pressure is created within a system housing of an air handling system. Particulate matter is filtered on a filter media of an air filter. A displaceable baffle is progressively moved baffle in proportion to an accumulation of particulate matter on the filter media, wherein the displaceable baffle is movably mounted within a bypass conduit of an airflow sensor device. An output voltage is identified from a magnetic field sensor, wherein the output voltage is proportional to a magnetic flux density of a magnetic field from an actuation magnet mounted on the displaceable baffle. A position of the displaceable baffle is determined based on the output voltage generated by the magnetic field sensor. An accumulation of particulate matter on the filter media is determined based on the position of the displaceable baffle.

Various systems and methods are provided for a mass flow rate sensor. In one example, a mass flow rate sensor comprises a first signal input, a second signal input, an output for a mass flow rate signal, a first characteristic field, a second characteristic field, each of the first and second characteristic fields associating a mass flow rate value with a pair of values of a revolution rate value and an output pressure value, and a selection unit that comprises a first parameter input and a second parameter input, the selection unit configured to produce a selection signal depending on a pair of parameters respectively received via the first and second parameter inputs and to switch the mass flow rate value of either the first or the second characteristic field through to the output of the mass flow rate sensor depending on the selection signal.

Various systems and methods are provided for a mass flow rate sensor. In one example, a mass flow rate sensor comprises a first signal input, a second signal input, an output for a mass flow rate signal, a first characteristic field, a second characteristic field, each of the first and second characteristic fields associating a mass flow rate value with a pair of values of a revolution rate value and an output pressure value, and a selection unit that comprises a first parameter input and a second parameter input, the selection unit configured to produce a selection signal depending on a pair of parameters respectively received via the first and second parameter inputs and to switch the mass flow rate value of either the first or the second characteristic field through to the output of the mass flow rate sensor depending on the selection signal.

A flow monitoring system is described for monitoring flow of a mixed-phase sample comprising at least a first phase and a second phase having different electrical conductivities, the second phase being a liquid or a gas and substantially electrically non- conductive and the first phase being a liquid and having a conductivity higher than the second phase. The system comprises: a conduit through which the mixed-phase sample can be arranged to flow; tomography apparatus arranged to generate tomography data indicative of at least a first conductivity profile of at least a portion of a first cross section of the mixed phase sample when flowing through the conduit; a flow meter arranged to detect flow of the first phase though the conduit and provide a flow signal indicative of a flow velocity of the first phase; and processing means adapted to calculate, from said data, a fraction of said first cross section occupied by the first phase, and calculate, from said fraction and said flow signal, a volumetric flow rate of the first phase through the conduit.

A flow monitoring system is described for monitoring flow of a mixed-phase sample comprising at least a first phase and a second phase having different electrical conductivities, the second phase being a liquid or a gas and substantially electrically non- conductive and the first phase being a liquid and having a conductivity higher than the second phase. The system comprises: a conduit through which the mixed-phase sample can be arranged to flow; tomography apparatus arranged to generate tomography data indicative of at least a first conductivity profile of at least a portion of a first cross section of the mixed phase sample when flowing through the conduit; a flow meter arranged to detect flow of the first phase though the conduit and provide a flow signal indicative of a flow velocity of the first phase; and processing means adapted to calculate, from said data, a fraction of said first cross section occupied by the first phase, and calculate, from said fraction and said flow signal, a volumetric flow rate of the first phase through the conduit.

A method for determining the flow rates of a fluid comprising a multi-component mixture of a gas and at least one liquid in a pipe, the method comprising the following steps: a. The temperature and pressure of the multi-component mixture is determined, b. the fractions of the multi-component mixture is determined based on at least two measured physical properties of the multi-components mixture and knowledge of the same physical property of the individual components of the multi-component mixture, c. the velocity of the multi component mixture is determined, d. based on the result from step a-c, the flow rate of the individual component of the fluid is determined, characterized by a method for determining the physical properties of at least one of the components of the multi-component mixture where e. an electromagnetic loss or phase measurement is performed, f. a statistical parameter related to the electromagnetic measurement is calculated, g. the said statistical parameter is compared to an empirical derived threshold value corresponding to the value of the statistical parameter when only one of the component of the multi component mixture is present, and h. the said physical properties of said fluid is determined if the statistical parameter exceeds the threshold value for the said component and used in step b-d to provide an improved value of the fractions, velocity and flow rate of the individual components of the multi-component mixture. An apparatus for performing the method is also disclosed.

A method for determining the flow rates of a fluid comprising a multi-component mixture of a gas and at least one liquid in a pipe, the method comprising the following steps: a. The temperature and pressure of the multi-component mixture is determined, b. the fractions of the multi-component mixture is determined based on at least two measured physical properties of the multi-components mixture and knowledge of the same physical property of the individual components of the multi-component mixture, c. the velocity of the multi component mixture is determined, d. based on the result from step a-c, the flow rate of the individual component of the fluid is determined, characterized by a method for determining the physical properties of at least one of the components of the multi-component mixture where e. an electromagnetic loss or phase measurement is performed, f. a statistical parameter related to the electromagnetic measurement is calculated, g. the said statistical parameter is compared to an empirical derived threshold value corresponding to the value of the statistical parameter when only one of the component of the multi component mixture is present, and h. the said physical properties of said fluid is determined if the statistical parameter exceeds the threshold value for the said component and used in step b-d to provide an improved value of the fractions, velocity and flow rate of the individual components of the multi-component mixture. An apparatus for performing the method is also disclosed.

Multiphase flowmeters and related methods are disclosed herein. An example multiphase flowmeter includes a microwave transmitter to transmit a signal through a fluid, a microwave receiver to determine at least one of attenuation or phase shift, a sensor to obtain at least one of pressure, temperature, or differential pressure, an intermediate-output generator to determine intermediate flow parameters, and a flow rate generator to determine a flow rate for respective phases in the fluid, and a model selector to select at least one of a physics model or a machine learning model for determining the intermediate flow parameters or the flow rates, the physics model to determine a first value of the intermediate flow parameters or the flow rates, and, in response to an error not being less than a threshold, the machine learning model to determine a second value of the intermediate flow parameters or the flow rates.