An electrochemical sensor may measure the flow of ions and/or electrochemical species in a solution passing the sensor because the electroactive species will continually come into contact with the electrode and an electric signal will be generated by the combination of diffusion and convection bringing the electroactive species to the electrode. The electric signal measured will vary by concentration of ions and/or electrochemical specie(s) and by flow rate. Flow rate may be measured if the concentration of ions and/or electrochemical specie(s) is known; conversely, the concentration of ions and/or electrochemical species may be measured if the flow rate is known. The sensor may also be used to confirm the delivery of a fluid containing ions and/or electrochemical specie(s).