Abstract: An apparatus for determining the proportion of water within a mixture of water and a water-miscible solvent includes means for increasing the electrical conductivity of the mixture in proportion to the amount of water contained therein. In a particular embodiment this is done by passing a component stream of the sample through a replenishable bed of a salt, which salt is easily soluble in water but is relatively insoluble in the solvent. The dissolving of the salt introduces an appreciable number of conductive ions into the mixture, thereby enhancing its overall conductivity. A conventional detecting scheme measures the enhanced conductivity of the mixture, and means is provided for correlating this conductivity measurement to the proportion of water within the mixture.

Abstract: A chemically integrating dosimeter for measuring gases, composed of a dual membrane system and an internal electrolyte solution. The outer membrane is a gas permeation rate controlling membrane. The inner membrane is a microporous hydrophobic protective membrane interposed between the electrolyte solution and the outer membrane. The dosimeter makes accurate determinations of time integrated exposures to various gases in the atmosphere and can be conveniently used by workers in industrial environments over a wide range of field conditions.

Abstract: An improved electrochemical reference electrode for use in potentiometric determinations of species in solution. The body of the electrode is composed of a material substantially permeable to liquid water whose exterior surface, excepting a comparatively small area, is covered by a membrane through which water may pass only by diffusion and which is also ion impermeable. The small area which is not covered forms an opening through the membrane to the body. The body contains a saturated salt slurry. When the electrode is immersed in an aqueous sample solution, water diffuses through the membrane and is transported in bulk across the body. Upon entry into the slurry, the water dissolves the solid salt in the slurry to produce an electrolyte which in turn flows outward through the small area of the body which is not covered by the membrane, whereby a liquid junction is provided between the electrolyte and the sample solution.

Abstract: An improved gas-sensing electrochemical cell for measuring hydrogen cyanide gas in a sample solution. The cell comprises a potentiometric silver ion-sensitive electrode and a reference electrode, both in contact with an internal standard solution comprising an aqueous solution of an argento cyanide complex. A hydrophobic hydrogen cyanide gas-permeable membrane separates the sample solution from the internal solution.