pH electrode method

Definition

Electrode methods relate hydrogen-ion behavior to measurable voltage, letting acidity be treated as a quantity rather than just a color change. They made precise pH measurement possible.

For the first time acidity could be measured numerically, though the resulting concentrations were buried under six or seven decimal places and spanned enormous ranges. That raw measurability, accurate but unmanageable, is what pushed Sørensen to compress the data onto a logarithmic scale. Modern analyzers also apply temperature compensation to correct electrode response.

Related concepts

Logarithmic scale · pH · Litmus test

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Part of The Blueprint of Water · 📏 measurement