Van London (also known as Vatco) is a manufacturer of electrochemical analytical sensors. It specializes in manufacturing pH, ORP (oxidation-reduction potential), conductivity, oxygen, and ion-selective electrodes designed for laboratory, industrial, biotechnology, and medical applications. Its product lines include tabletop meters, portable meters, industrial transmitters, and other related products. Van London merged with pHoenix Electrode to create Van London-pHoenix.