Measuring system for amperometric chemical sensors using the three-electrode technique for field application

A portable and low cost measuring system for amperometric chemical sensors using the three-electrode technique was developed. This technique allows chemical sensors to work with currents higher than ten microamperes. The system was based on a potentiostat operation, completed with an I-V converter and signal conditioning circuits. The instrument was evaluated comparing calibration curves of hydrogen peroxide, proving several amperometric chemical sensors and biosensors, to those obtained from a very expensive commercial equipment. Good linearity and sensibility as well as low noise measurements were obtained. Moreover, because the reduced size and low cost, the instrument allows to be used directly in field applications.