Abstract: The invention relates to a method of manufacturing a device for measuring conductivity of a liquid, in particular ultrapure water, of the kind comprising two conductivity measurement electrodes suitable for defining a cell constant enabling the measurement of the conductivity of the ultrapure liquid, characterized in that it consists of producing each of the electrodes by forming an electrode pattern from electrically conductive material on a substrate of insulating material. It also relates to the conductivity measuring device obtained by that method and to a device for measuring the Total Organic Carbon quantity implementing that conductivity measuring device.

Abstract: The invention relates to a method of manufacturing a device for measuring conductivity of a liquid, in particular ultrapure water, of the kind comprising two conductivity measurement electrodes suitable for defining a cell constant enabling the measurement of the conductivity of the ultrapure liquid, characterized in that it consists of producing each of the electrodes by forming an electrode pattern from electrically conductive material on a substrate of insulating material. It also relates to the conductivity measuring device obtained by that method and to a device for measuring the Total Organic Carbon quantity implementing that conductivity measuring device.

Abstract: An electrodeionization device for large-volume ultra-pure deionization of water is disclosed. The device comprises a plurality of alternating ion depletion and concentration compartments, interposed between an anode assembly and a cathode assembly, through which flows either a product stream or a waste stream. Each compartment contains several fluid-accessible channels packed with an appropriate ion-exchange medium. The flow of the waste and product streams among the compartments is “parallel” (i.e., contemporaneous). The flow of a stream through the compartments—i.e., through the channels therein—is “serial” (i.e., sequential). In an embodiment, electrical current is generated through the compartments using segmented electrodes—either in the anode and/or the cathode assembly—that are connected to a single multiple-outlet power source. The device is fast, efficient, robust, and its configuration is comparatively easy to scale upwards to accommodate larger water processing volumes.

Abstract: A rapid, highly sensitive determination, in-situ, of the integrity and/or pore size distribution of a porous membrane structure (e.g. a pleated membrane filter cartridge) is disclosed. The identification of the integrity and/or pore size characteristics involves interpreting the residence time distribution (RTD) of the membrane structure under test and includes using a tracer gas in mixture with a carrier gas as part of a diffusion or bubble-point test. The tracer gas mixture exiting the downstream surface of the membrane becomes moisturized and is excited with a pulsed (or otherwise modulated) light source at a wavelength corresponding to the absorption line of the tracer gas. The frequency of modulation is chosen such that the tracer gas preferentially generates a photo-acoustic emission while the emission due to the absorption of water present is suppressed. The detected pressure pulse is processed to produce electrical signals indicative of the concentration of tracer gas that passes through the membrane.