ANDREW LAMBERT PHOTOGRAPHY / SCIENCE PHOTO LIBRARY ANDREW LAMBERT PHOTOGRAPHY / SCIENCE PHOTO LIBRARY
Measuring acidity using a pH meter probe. The tip of the probe is immersed in potassium dichromate solution (orange), which is acidic. The glass bulb of the probe contains electrodes that measure the electrical potential of the hydrogen ions. This is directly related to pH, which is a measure of the concentration of hydrogen ions.
Model release not required. Property release not required.