pH Measurement with Arduino

In chemistry, pH is the negative log of the activity of the hydrogen ion in an aqueous solution. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline. Pure water has a pH of 7. Contrary to popular belief, this value can extend past 0 or 14 for sufficiently concentrated acids and bases, however it is difficult to measure precisely.
The pH scale is traceable to a set of standard solutions whose pH is established by international agreement. Primary pH standard values are determined using a concentration cell with transference, by measuring the potential difference between a hydrogen electrode and a standard electrode such as the silver chloride electrode. Measurement of pH for aqueous solutions can be done with a glass electrode and a pH meter, or using indicators.
Mathematically, pH is the negative logarithm of the activity of the (solvated) hydronium ion, more often (albeit somewhat inaccurately) expressed as the measure of the hydronium ion concentration.

Components Required for pH Measurement

ph Measurement Components
ph Measurement Components

pH Measurement Arduino Circuit

Do not solder on pH Module, it is high sensitive, high impedance circuit. You may easily damage it by soldering wires on it, Never cut or solder the BNC Connector wires.

Arduino ph Measurement Circuit
ph Measurement Circuit

pH Measurement Arduino Code


Open Serial Monitor and observe the result with different pH solutions.

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