Abstract: The present invention is a current sensor architecture using a planar coils in close proximity to a current conductor to detect the rate of change of current in the conductor (and hence, by using an integrator, to recover the AC current). The current sensor is optimised to reject uniform external magnetic fields, gradient external magnetic fields, and fields from one or more conductor assemblies in fixed locations in close proximity to the current sensor, such as might be found in a polyphase electric meter with multiple current sensors.

Abstract: A gas meter comprises a conduit for passage of a gas flow and an ionizer to ionize the gas flow. A modulating electrode structure downstream of the ionizer modulates the ion distribution in the ionized gas flow. A first and a second electrode structure downstream of the modulating electrode structure detect the ion distribution in the ionized gas flow. The modulating electrode structure and the detecting electrode structure can generate an electrical field parallel to the direction of the gas flow. The modulating electrode structure and the detecting electrode structures can each have apertures defined therein for passage of the gas flow. The modulating electrode structure can capture ions of one polarity to generate an ionized gas flow comprising a majority of ions of the opposite polarity. Movement of the ionized gas flow generates a current indicative of the ion distribution between the electrode and the charge source.

Abstract: A method of measuring chlorine concentration of a solution comprising making a first measurement of transmission of ultraviolet light at a selected wavelength through a first sample of said solution at a first temperature; making a second measurement of the transmission of ultraviolet light at said selected wavelength through a second sample of said solution at a second temperature, said second temperature being different than said first temperature; and determining the chlorine concentration in said solution using the results of said first and second measurements.

Abstract: A gas meter gas a conduit for passage of a gas flow; an ioniser arranged to ionise the gas flow in the conduit; a modulating electrode structure arranged for modulating the ion distribution in the ionised gas flow; and at least a detecting electrode structure downstream of the modulating electrode structure arranged for detecting the modulated ion distribution in the ionised gas flow. The modulating electrode structure is arranged downstream of the ioniser and is configured to generate an electrical field which is substantial in a parallel to the direction of the gas flow.

Abstract: A method of inference of appliance usage from a point measurement on a supply line, said supply line being common to multiple appliances and/or components of appliances comprises the steps of: obtaining data from said measurement point; sampling power and reactive power at intervals substantially throughout periods of operation of said appliances or components of appliances corresponding to appliances or components of appliances being in ON and/or OFF modes of use; identifying characteristics of events by assessing power and reactive power change during an event; and by assessing one or more additional characteristics derivable from said power and reactive power to characterise an appliance; grouping events and/or cycles of events into clusters of similar characteristics; and inferring appliance usage based on said grouping.

Abstract: Apparatus for monitoring the voltage of electricity supplied on a cable (121) are described. The apparatus includes a sense electrode housed in an electrically-insulative housing to form a capacitive coupling (127) between the sense electrode and the cable. The housing may be of the clamp-on type. A sense capacitor (128) of known capacitance is included, which is electrically coupled to the sense electrode and a local ground. Suitable voltage measurement circuitry (126) is connected to the sense capacitor and is responsive to voltage produced across the sense capacitor to provide an output signal representative of the voltage on the cable. The measured voltage waveform can be filtered to give the fundamental of the supply voltage, which can eliminate or reduce the effects of changes in capacitance within one cycle. A secondary capacitive (130) coupling can be formed with a related neutral wire (122) to improve stability of the voltage waveform measurement.

Abstract: A gas meter comprises a conduit (1) for passage of a gas flow A and an ioniser (2) arranged to ionise the gas flow in the conduit (1). A modulating electrode structure (4) downstream of the ioniser modulates the ion distribution in the ionised gas flow. A first detecting electrode structure (8) and a second electrode structure (9) downstream of the modulating electrode structure 4 detect the modulated ion distribution in the ionised gas flow. The modulating electrode structure (4) and the detecting electrode structures (8, 9) can be configured to generate an electrical field having at least a substantial component parallel to the direction of the gas flow. The modulating electrode structure (4) and the detecting electrode structures (8, 9) can comprise a pair of electrodes (5, 6, 10, 11), each having a plurality of apertures defined therein for passage of the gas flow.

Abstract: The present invention is a current sensor architecture using a planar coils in close proximity to a current conductor to detect the rate of change of current in the conductor (and hence, by using an integrator, to recover the AC current). The current sensor is optimised to reject uniform external magnetic fields, gradient external magnetic fields, and fields from one or more conductor assemblies in fixed locations in close proximity to the current sensor, such as might be found in a polyphase electric meter with multiple current sensors.

Abstract: A method of measuring the free chlorine level in a solution of chlorinated pool/spa water comprises a first sample of said solution having a first selected pH and a second sample of said solution having a second selected pH and determining first and second ultraviolet light (UV) transmissivity values for each of the first and second samples. The first and second transmissivity values are then used to determine the free chlorine level.

Abstract: An apparatus for use in measuring the free chlorine level in a solution of halogenated pool/spa water includes a pH adjusting device for producing a first sample of said solution having a first selected pH and a second sample of said solution having a second selected pH, as well as a spectral analyzer for determining first and second ultraviolet light (UV) transmissivity values for each of the first and second samples. An electronic processor receives the first and second transmissivity values and determines the free chlorine or bromine level using those values.

Abstract: A method of measuring chlorine concentration of a solution comprising making a first measurement of transmission of ultraviolet light at a selected wavelength through a first sample of said solution at a first temperature; making a second measurement of the transmission of ultraviolet light at said selected wavelength through a second sample of said solution at a second temperature, said second temperature being different than said first temperature; and determining the chlorine concentration in said solution using the results of said first and second measurements.

Abstract: An apparatus for use in measuring the free chlorine level in a solution of halogenated pool/spa water includes a pH adjusting device for producing a first sample of said solution having a first selected pH and a second sample of said solution having a second selected pH, as well as a spectral analyzer for determining first and second ultraviolet light (UV) transmissivity values for each of the first and second samples. An electronic processor receives the first and second transmissivity values and determines the free chlorine or bromine level using those values.

Abstract: A method of measuring the free chlorine level in a solution of chlorinated pool/spa water comprises a first sample of said solution having a first selected pH and a second sample of said solution having a second selected pH and determining first and second ultraviolet light (UV) transmissivity values for each of the first and second samples. The first and second transmissivity values are then used to determine the free chlorine level.

Abstract: In a biological measurement system (10) for collecting one or more samples of sputum and/or mucus from a patient in the form of an aerosol and for analyzing said one or more samples to detect whether or not pathogens are present therein, the one or more samples are in solution within the system (10) and detection of the pathogens is performed using a fluorescently labeled assay. The system (10) is adapted to detect bacterial pathogens using evanescent-wave spectroscopy preferably by using a single-reflective technique. The one or more samples are advantageously provided to the system (10) in aerosol form. However, the system (10) is capable of being adapted for use in analyzing samples in liquid form. Methods of analyzing said one or more samples in the system (10) are described.

Abstract: In a biological measurement system (10) for collecting one or more samples of sputum and/or mucus from a patient in the form of an aerosol and for analysing said one or more samples to detect whether or not pathogens are present therein, the one or more samples are in solution within the system (10) and detection of the pathogens is performed using a fluorescently labeled assay. The system (10) is adapted to detect bacterial pathogens using evanescent-wave spectroscopy preferably by using a single-reflective technique. The one or more samples are advantageously provided to the system (10) in aerosol form. However, the system (10) is capable of being adapted for use in analysing samples in liquid form. Methods of analysing said one or more samples in the system (10) are described.

Abstract: A current sensor for measuring the load in a fiscal power meter has conductive paths connected between an inlet and an outlet for guiding the load currents through the sensor, and operates by sensing local magnetic fields generated around the conductive paths by the current flowing there through, thereby providing a current measure indicative of the magnitude of a given load. The sensor is distinguished by plural current coil elements arranged in a substantially common plane so as to be substantially insensitive to remotely generated magnetic fields but responsive to local magnetic fields for generating the current measure. The coil elements are disposed in zones having more than two effective centres and exhibiting mutually opposing responses to the remote field.

Abstract: A current sensor for measuring one or more currents supplied from a power source to a load, the sensor comprising: