It's easy to take for granted that pH meters exist and are fairly easy to use. If we think in more historical terms, however, it's actually pretty amazing. contact BOQU Instrument: michael@shboqu.com that talks about how the pH meter lets us investigate nature in ways that early chemists wouldn't even dream of.

How does a pH meter work?

A pH meter is consisted of three different parts: an internal electrode, a reference electrode, and a high input impedance meter. Glass probe often contains two electrodes -- an internal electrode and a reference electrode. The internal electrode is a Silver wire covered with Silver Chloride (Ag/AgCl wire), and the reference electrode is often made up of the same materials. Inside the probe is a buffer solution at a pH of 7. Measured pH is the difference in [H+] between the reference buffer inside the probe and the sample solution.

The pH measurements are made by comparing the pH reading of a sample solution to that of a reference solution with defined pH, such as buffers. Therefore, it is important to calibrate the instrument with appropriate buffer solutions before making any measurements. The figure on the right is a simple depiction of a glass electrode used with pH meters (Source: Electrochemistry Theory and Practice, BOQU Instrument).

For more information on calibration, please contact the engineer of BOQU Instrument.