Novel thick-film pH sensors based on ruthenium dioxide-glass composites

摘要: Abstract Potentiometric pH electrodes are described, which consist of 30 μm films a ruthenium dioxide-glass composite, prepared by sintering mixtures powdered lead borosilicate glass and dioxide hydrate onto Pyrex substrates at 900 °C. Electrical contact is made either point remote from the solution-contacting portion electrode or via platinum wire immediately underlying active area. Composite with an RuO 2 :lead ratio 1:1 show near-Nernstian dependence potential upon in aqueous buffer between 12, maximum hysteresis mV response time approximately 90 s. Response rates appear to be limited diffusion protons through porous composite decrease decreasing :glass ratio. The completely indifferent changes concentration dissolved oxygen, but small chloride ions. Changes characteristics aging reported, most significant −65 drift E 0 .