Abstract: A cell body having a pair of electrodes insulated from each other and adapted for direct immersion and use in commercial, laboratory, or industrial fluids or process streams, the cell being usable at temperatures below freezing and above the boiling point of water. The cell includes an insulated ultra pure antimony electrode and an insulated electrode of noble metal, the noble metal of the one electrode being immersed in the process stream as is the pure antimony electrode. The cell provides a self-contained solid state unit with the two electrodes adapted to measure pH in fluids or process streams containing solid mineral or ore particles, in acid, neutral or basic solutions of a wide range of temperatures and pressures, including vacuum applications and this system requires no external or internal reference or standard electrodes.

Abstract: A simplified system for practical use in the measurement of specific ion concentrations. A probe for introduction into a fluid stream to measure the ion concentration thereof and said probe comprising an ion sensitive electrode for immersion in a fluid stream in combination with an annular elongated electrode having a noble metal, such as one of the platinum group of metals, on an end surface thereof for immersion in the fluid stream. The combination of the ion sensitive electrode, and the annular elongated electrode having an end thereof with the noble metal is placed in the fluid stream to be measured and is electrically connected to a measurement and/or indicating instruments.