What is a pH sensor probe?

The pH sensor probe contains two electrodes (a sensor electrode and a reference electrode) to measure the hydrogen ion activity in a solution. The ion exchange generates a voltage, which is measured by a pH meter, which converts the voltage into a readable pH value. It is a water quality sensor that measures the pH of a liquid.

pH (hydrogen potential) A solution in which a large number of hydrogen ions are active is an acid. Conversely, a solution with a lot of hydroxide ion activity is a base. Measuring pH with pH sensor probes is important to a wide range of industries, which is why there are different pH sensors for different applications. Next we'll look at how a pH probe works, what a pH sensor measures, and what's inside a pH probe.

How do ph probes work?

A common practice for measuring the pH of a solution is to use litmus paper. It turns different colors according to the pH chart regardless of the hydrogen ion content, however, a pH meter must use a pH probe to measure the hydrogen ion concentration.

A pH meter works by measuring the electrical potential (voltage) generated by the solution being tested and using the potential difference to determine the pH value. An acidic solution has more positively charged hydrogen ions than a basic solution, therefore, the solution has a greater potential to generate an electric current.

A pH meter consists of three parts: the pH meter itself (moving coil or digital), a pH electrode, and a pH probe inserted into the solution being measured.

Most pH probes contain two electrodes inside the body: a measuring electrode (a glass electrode) and a reference electrode. The glass electrode contains a reference electrolyte (usually potassium chloride) which has a neutral pH of 7 and therefore contains a specific amount of hydrogen ions.

Glass electrodes work by measuring the difference in pH between the pH electrode and the solution being measured. The electrodes do this by measuring the voltage difference between the electrodes and the hydrogen ions produced in solution. This is easy to fix since we already know the pH of the glass electrode combination.

Are pH probes and pH meters the same?

A pH probe is part of a pH meter, so technically they are not the same, however, they cannot function without each other. A pH meter consists of three parts: a pH probe, a reference pH electrode, and the pH meter itself. It is the electrodes inside the pH probe that measure the pH of the solution.

The pH probe records the voltage of the hydrogen ions, and by measuring the difference between the electrode inside the pH probe and the reference electrode, the voltage is converted into a pH value readable by the pH meter. The pH probe is connected to the display panel of the pH meter to display the measured pH value.