MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY
Hydrogen electrode apparatus. Standard hydrogen electrodes are devices constructed to provide a standard baseline against which to measure oxidation-reduction potentials. The standard form of this apparatus uses a platinum electrode, with hydrogen pumped in through the glass tube (right). The liquid is hydrochloric acid. In use, this standard hydrogen electrode (SHE) is connected to another electrode (not seen), which will be using a different metal. The difference in voltage will be the electrode potential for that metal. This is because the hydrogen electrode potential is defined as zero.
Model release not required. Property release not required.