Abstract: An electrode assembly includes a hollow outer body, a cap, a biasing assembly, an actuator, and a sensing electrode having a hollow stopper at a lower end thereof. The outer body includes a lower edge that defines a lower opening. The cap is fixedly coupled to the outer body so that the cap does not move with respect to the hollow outer body. The biasing assembly is operatively coupled to the hollow outer body and the sensing electrode, and urges the sensing electrode upward so that an outer surface of the stopper is normally in contact with the lower edge of the outer body. The actuator is configured to move relative to the outer body so that when force is applied to the actuator, the stopper separates from the lower edge of the outer body, thereby allowing an electrolytic solution to flow out of the outer body.