Abstract: An ion selective microelectrode in which the reference solution is an aqueous solution of formamide (or methyl formamide) and in which the ionophore-containing membrane covering the reference solution is PVC dissolved in water-insoluble 3-methylcyclohexanone (or equivalent substituted cyclic ketone). The reference solution may be gelled with PVA and preferably is buttressed to assure against incursion of membrane components.

Abstract: The present invention relates to an arrangement for producing an ice slush from an aqueous liquid which passes through at least one conduit (1) having cooled walls, and in which ice particles (13) can form. For the purpose of preventing ice from building-up on the cooled conduit walls, the arrangement includes means (10) for creating at least one helical, rotational path (11, 12) in the liquid such as to cause the liquid to contact the cooled wall surfaces of the conduit. Due to the lower density of the ice particles (13) generated in the liquid, the ice particles are drawn towards the center of the helical liquid flow (11, 12), while the heavier liquid particles move out towards the cooled walls of the conduit, under the influence of the gravitational forces generated.