The invention comprises portable, rugged and relatively compact electrochemical cells. Each may be removably and nondestructively secured to one surface of a substrate of indefinite size. In-situ electrochemical measurements may be made on portions of existing structures such as ships, bridges, or buildings. An electrochemical cell is disclosed which comprises an analytical chamber which can be utilized with either on-board or external potentiostats. The electrochemical cell has a mounting means which permits the cell to be secured to substrates with irregular surface morphology and to horizontal, vertical or intermediately oriented surfaces. The electrochemical cell provides a means to control the temperature of the electrolyte and the substrate area of interest to permit more accuract and consistent elecrochemical measurements. Said probe is capable of performing electrochemical measurements such as a monitoring corrosion, effectiveness, or integrity of conductive and nonconductive coatings on bare and coated metallic or conductive substrates.