A potentiostat based on a voltage-controlled current source for use with amperometric gas sensors

Amperometric gas-sensing devices develop a current that is proportional to the concentration of gas that is supplied to them. The circuit that maintains electrochemical stability in the sensor as well as buffering the current output is called a potentiostat. Some sensors used for gas sensing have very large electrode capacitances, which can result in instability with conventional potentiostat designs. The responses of two potentiostat designs to a gas were compared. One is based on conventional use of a current-to-voltage converter (CVC); the second is a new design which uses a voltage-controlled current source (VCCS). A frequency analysis of the VCCS potentiostat design is included