41 results about "EMF measurement" patented technology

A magnetic flow metering device and method is disclosed for the measurement of corrosive flow streams. The device utilizes a unibody construction wherein the flow conduit is constructed entirely from an insulative, non-conducting material without resorting to a metallic outer housing. The portions of the electrodes in contact with the flow stream are made of a suitable conductive polymer material, resistant to the corrosive media. The electrodes also feature shields that are molded into the electrode assembly to reduce background electrical noise. The invention also utilizes an electrical configuration that actively drives the electrode shield circuit (electrodes as well as cabling) to provide a more accurate measurement of the electromotive force.

A motor torque measurement system includes a motor in communication with a gyro, a centrifuge rotor connected to the gyro, a housing surrounding the rotor and motor, and a controller in communication with the motor. The controller is connected to a back EMF measurement device, which measures the back EMF of the motor, and is also configured to measure motor rotational speed. The back EMF coefficient (Ke) and motor torque constant (Kt) can be calculated therefrom and the actual motor performance thereby determined. Motor magnet temperature may also be calculated. Back EMF and motor rotational speed measurements may be taken with the motor coasting.

There is provided an apparatus, comprising: at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to: perform a set of Earth's magnetic field, EMF, measurements inside a building, wherein each EMF measurement result represents at least one of a magnitude and a direction of the EMF in the building;store the set of EMF measurement results off-line into a memory buffer coupled to the apparatus; and upon detecting a predefined triggering condition, cause a transfer of the stored set of EMF measurement results to a database entity.

In an imaging apparatus having a toner container, a method of periodically calibrating a back EMF constant Ke used in a speed control circuit of a DC motor used for driving for a toner metering device. To adjust the value of the back EMF constant Ke, the method uses a plurality of sampled back EMF measurements together with a calculated actual speed of rotation of the toner metering device as measured using motion sensor.

The invention relates to an electromagnetic flowmeter for non-full pipe flow measurement, comprising an electromagnetic flow transducer, an electrical impedance measurement module, an induced electromotive force measurement module and a control and signal processing module. The electromagnetic flowmeter is characterized in that the electromagnetic flow transducer comprises a measuring pipe, an electrode and a magnet exciting coil; the electrical impedance measurement module includes a multi-way switch group A, an excitation signal source circuit and an electrical impedance measurement circuit; the induced electromotive force measurement module comprises a multi-way switch group B, an exciting circuit and an induced electromotive force measurement circuit; and the control and signal processing module is in charge of controlling the multi-way switch group A and the multi-way switch group B, the electrical impedance measurement module is used for obtaining a plurality of groups of electrical impedance values, and the induced electromotive force measurement module is used for obtaining a plurality of groups of induced electromotive force values, so that the flow rate inside a pipe can be obtained under the conditions of full pipe and non-full pipe. The electromagnetic flowmeter can realize accurate measurement of the flow rate without calibrating different fluid mediums in a state of non-full pipe flow.

Entrainment fluid detection diagnostics. A magnetic flowmeter includes at least one coil configured to generate a magnetic field in a process fluid flow. The electrode pair is configured to detect an electromotive force generated in the flowing process fluid in response to the magnetic field. A measurement circuit is coupled to the pair of electrodes and configured to provide an indication of the detected electromotive force. A processor is coupled to the measurement circuit and configured to receive an indication of the detected electromotive force and determine a flow-related output based on the detected electromotive force. The diagnostic assembly is configured to analyze a number of continuous parameters of the magnetic flowmeter to provide an indication of detected entrained fluid.