Abstract: A method and handheld apparatus for the measurement of liquid density comprising a handheld enclosure which encases a differential pressure transducer having each pressure orifice connected by separate tees to separate hollow bubble tubes. Each bubble tube is connected on one end to a common micro-pump providing a balanced and relatively constant gas flow in each hollow bubble tube. The other ends of the bubble robes are terminated outside of the enclosure at relatively fixed and different distances from the enclosure in an arrangement that provides for the bubble tubes to be encased in a free hanging probe that will hang substantially vertical and will access liquid chamber diameters down to 1/4 inch. The apparatus measures density by vertically orienting the open ends of each hollow bubble tube in a liquid and measuring the differential pressure at the open ends of the bubble tubes created by the weight of the liquid at their respective depths.

Abstract: An electrolytic gas generating apparatus for producing a combustible mixture of hydrogen and oxygen by electrolysis of water is disclosed, for particular use in a gas welding apparatus. The generating apparatus comprises a d.c. power supply 100 connected to electrolytic cells 200, a dehumidifier 400 for scrubbing the gas mixture generated by the cells 200, a gas regulator 500, a modifier 600 which modifies the combustion characteristics of the gas and a flash arrester 660. Gas generation is controlled by a main control board 800 in accordance with sensors which measure parameters to calculate indirectly the gas flowrate and control this in accordance with demand.