Ph Orp Sensor

Both pH and ORP measurements are based on electrochemical principles, converting chemical signals into measurable electrical signals through an electrode system.

pH Measurement Principle
pH measurement employs the glass electrode method. Its core is a special glass membrane sensitive to hydrogen ions (H⁺).
Potential Difference Generation: When the glass electrode is immersed in the test solution, a potential is generated due to the difference in H⁺ activity on both sides of the glass membrane.
Nernst Equation: This potential difference has a linear relationship with the pH value of the solution, as described by the Nernst Equation.
Signal Measurement: By measuring the potential difference between the glass electrode and a stable reference electrode (typically a silver/silver chloride electrode), the pH value of the solution can be accurately calculated.

ORP Measurement Principle
ORP measurement employs the metal electrode method to measure the tendency of a solution to gain or lose electrons, indicating the strength of its oxidizing or reducing capability.
Inert Electrode: The sensor uses a chemically stable inert metal (such as platinum (Pt) or gold (Au)) as the measuring electrode.
Electron Exchange: When the inert electrode is immersed in a solution containing oxidizing or reducing agents, a slight electron exchange occurs on the electrode surface until equilibrium is reached.
Potential Measurement: At this point, a stable potential difference is generated between the inert electrode and the reference electrode. This potential difference is the ORP value, measured in millivolts (mV). A positive value indicates an oxidizing environment, while a negative value indicates a reducing environment.