Abstract: A method measures electrical impedance of electromagnetic flowmeter sensing electrodes includes intermittently injecting an impedance measurement signal to at least one sensing electrode while a coil excitation drive signal is applied to flowmeter field generating coils. During a first interval, when the coil excitation drive signal is applied to the coils and the impedance measurement signal is injected to a sensing electrode, a first measurement signal is obtained. The first measurement signal includes an electromagnetically induced flow measurement signal and an electrode impedance measurement signal. During a second interval, when the coil excitation drive signal is applied to the coils but the impedance measurement signal is not injected to the sensing electrodes, a second measurement signal is obtained that includes an electromagnetically induced flow measurement signal.

Abstract: A method and apparatus are for processing a periodic data-carrying signal to reduce periodic interference at either of a first fundamental frequency or a second fundamental frequency, the second fundamental frequency being different from the first fundamental frequency. The periodic data-carrying signal is derived from an excitation signal having an excitation frequency, the excitation frequency being a sub-multiple of the first fundamental frequency. The data-carrying signal is subjected to both a comb filter to reject interference at the first fundamental frequency, and an averaging/integrating filter to reject interference at the second fundamental frequency. A comb filter delay period is related to the first fundamental frequency and the averaging/integrating filter averages or integrates over a period related to the second fundamental frequency.

Abstract: Methods and apparatus are for storing and retrieving data related to the installation, service, repair or performance of an industrial flow meter or other measurement instrument. Methods and apparatus are also for other processes associated with measurement instruments.

Abstract: A conductivity sensor is described in which electrodes are held in a desired position within a housing of the sensor by a number of slots accurately positioned within the housing. In one embodiment the slots are integrally formed within the housing. Once the electrodes have been inserted into the slots a thermoset resin is poured into the housing and cured. A through bore is then drilled through the housing, the electrodes and the cured resin to form a flow conduit through the sensor. A dual frequency excitation technique is also described that allows a measurement to be obtained of a polarization resistance of the electrodes. In one embodiment this measurement is stored and used to correct subsequent conductivity measurements.

Abstract: A conductivity sensor is described in which electrodes are held in a desired position within a housing of the sensor by a number of slots accurately positioned within the housing. In one embodiment the slots are integrally formed within the housing. Once the electrodes have been inserted into the slots a thermoset resin is poured into the housing and cured. A through bore is then drilled through the housing, the electrodes and the cured resin to form a flow conduit through the sensor. A dual frequency excitation technique is also described that allows a measurement to be obtained of a polarisation resistance of the electrodes. In one embodiment this measurement is stored and used to correct subsequent conductivity measurements.

Abstract: A flux control system for a three-phase active voltage conditioner that utilizes an injection transformer to apply calculated compensation voltage to a mains supply. The flux control system is configured to modify the compensation voltage to be applied to at least one primary terminal of the injection transformer so as to avoid magnetic saturation of the injection transformer. The flux control system includes magnetic flux model modules that are configured to calculate a core flux level of the injection transformer, flux offset modules that are configured to apply a first modification to the compensation voltage to gradually reduce any flux offset in the injection transformer, and peak flux modules that are configured to apply a second modification to the compensation voltage to prevent the core flux level from exceeding a preset range.

Abstract: A method of manufacturing an electromagnetic flow meter assembly is disclosed. The method comprises forming an insert from a deformable material, forming at least one reinforcing component; arranging the reinforcing component around a portion of the insert, and bonding the reinforcing component to the insert to reinforce the insert against deformation under the application of pressure. An electromagnetic flow meter assembly is also disclosed and comprises an insert for insertion into a flow conduit, wherein at least a portion of the insert is formed of a deformable non-ferromagnetic material, wherein the insert comprises an inlet section, a measuring section, and an outlet section. The assembly further comprises at least one reinforcing component surrounding the measuring section of the insert to reinforce the insert against deformation under the application of pressure.

Abstract: An electromagnetic flowmeter assembly is described in which an excitation field is set up across a flow conduit and electrodes are used to sense the electromagnetic field generated across the flow conduit as a result of interaction between the excitation field and fluid flowing along the flow conduit. The signals obtained from the electrodes are processed, together with stored calibration data, by processing circuitry to determine flow measurements and means is provided for dynamically updating the calibration data.

Abstract: An electromagnetic flow meter is described having a pressure containing vessel or conduit through which the fluid to be metered is passed. The pressure containing vessel is formed of first and second sections which are made of respective materials having first and second magnetic permeabilities, such as stainless steel and carbon steel. A single magnetic field generating coil is provided adjacent the first section for generating a magnetic field across the pressure containing vessel.

Abstract: An electromagnetic flow meter for measuring flow rate of a fluid passing therethrough includes a conduit defining a fluid inlet, a fluid outlet and a measuring section positioned between the inlet and the outlet. The flow meter also includes a single coil for generating a magnetic field across the measuring section and electrodes for detecting induced electrical potential due to the fluid passage. The flow meter also includes means for conditioning the flow through the measuring section. The combination of the single coil and the flow conditioning means provides a flow meter with a desired level of accuracy. The single coil and the electrodes may be arranged so that the integral of a weight function, which defines the sensitivity of the flow meter to fluid velocity through different parts of the measuring section, over the first half of a measuring section closest to the coil is between 0.4 and 1.3 times the integral of the weight function over the other half of the measuring section.

Abstract: An electromagnetic flow meter for measuring flow rate of a fluid passing therethrough includes a conduit defining a fluid inlet, a fluid outlet and a measuring section positioned between the inlet and the outlet. The flow meter also includes a single coil for generating a magnetic field across the measuring section and electrodes for detecting induced electrical potential due to the fluid passage. The coil may be arranged to surround a section of the measuring section over a segment angle of between 140 and 180 degrees. The electrodes may be positioned so that they are offset from being opposite each other on the centerline of the measuring section, by an offset angle of between 5 degrees and 45 degrees.

Abstract: A method of determining the inter-electrode or electrode-to-ground impedance or the filling state of an electromagnetic flow meter having flow sensing electrodes connected to an electrode signal amplifier, the method comprising applying a test input signal to the flow sensing electrodes via a connection through which an output flow measurement signal of the flow meter is transmitted from the amplifier, in a manner such that the output of the amplifier is indicative of the said impedance or the filling state.

Abstract: An insert for an electromagnetic flow meter is disclosed. The insert is arranged to be positioned within a flow conduit having a flow conduit cross-section to define a flow path for fluid, wherein the insert comprises an inlet, a measuring section with a measuring cross-section different from the flow conduit cross-section and having at least two substantially parallel sides over at least part of its length, and an outlet.

Abstract: A method of obtaining a plurality of measures of quantity of a substance flowing through a respective plurality of conduits is disclosed, wherein each of the conduits is supplied from an upstream common source location. An improved series of measurements are derived from an upstream absolute measure and downstream relative measures.

Abstract: An electromagnetic flow meter is disclosed which can be used to measure flow in low conductivity fluids, for example alcohol, turpentine, oil or other organic solvents. In one embodiment, the electromagnetic flow meter includes an elongate flow conduit having a direction of elongation corresponding to a direction of fluid flow, magnetic field generating means for generating a magnetic field across the flow conduit and potential sensing electrodes for sensing a potential generated by the magnetic field in a fluid flowing through the conduit. Both the field generating means and the potential sensing electrodes of the flow meter are elongate in the direction of flow.

Abstract: Methods and apparatus for determining the phase of a signal in a measurement device having a digital signal processor are described. The signal is digitised and the digitised signal, or a signal derived therefrom, is numerically correlated with a numerically generated reference signal. In one embodiment, the reference signal has a predetermined phase. In a further embodiment, the numerically generated reference signal has a reference phase and the phase is determined from the result of the correlation. The techniques described herein may reduce the amount of information lost in determining the signal phase.

Abstract: A filter assembly for ultra-filtration of fluids such as waste water comprises a porous tube which is incrementally advanced into the fluid so as to expose a fresh portion periodically and maintain a flow rate over a period of time.

Abstract: A meter for monitoring consumption of a resource, such as water or other fluids, and corresponding methods of configuring and operating the meter are disclosed. The meter includes processing and memory devices for determining and storing a supplier measure of consumption of the resource and a communication link for enabling a supplier to access the stored supplier measure. The supplier access is controlled by a first access control device, which prevents unauthorized access to the stored data. The meter further includes a consumer data memory for storing consumer data including a consumer measure of consumption and second access control device. The second access control device enables a consumer to access the stored consumer data without permitting the consumer to modify the stored supplier measure of consumption.

Abstract: A method of obtaining a measure of flow from an electromagnetic flow meter is disclosed. A shaped excitation waveform is applied to the flow meter and an output is received from the meter. The sampled output data from the meter is then resolved into a non-flow waveform component and a flow waveform component to derive a measure of flow. Resolving the data into expected waveform components rather than correlating each frequency component of the sampled output data with a sine wave may allow readings to be obtained without processing each frequency component separately. Also, the method may allow more accurate removal of the non-flow component from the output signal, and may decrease the time delay before the initial reading and allow the use of a greater reading repetition rate.

Abstract: There is described herein a method of obtaining a measure of flow from an electromagnetic flow meter having at least one field generating coil and potential sensing electrodes. A composite excitation waveform is applied to the field-generating coil. The composite excitation waveform comprises at least two frequency components and a plurality of frequency components are simultaneously present for at least a portion of the waveform. The potential sensed by the potential sensing electrodes is sampled to produce a sampled output and the sampled output is correlated with a composite waveform based on the composite excitation waveform. The result of the correlating is used to derive a measure of flow.