a clinometer includes a cyclindrical cavity having a conductive cylindrical wall and a vertical annular wall having a high resistance resistor uniformly distributed thereon . a freely moving , heavy conductive ball seeks the lowest point in the cavity . the conductive ball contacts both the conductive cylindrical wall and a point along the resistor , thereby defining the resistance between a terminal connected to one end of the resistor and another terminal connected to the conductive cylindrical wall . this resistance is a function of the inclination of the clinometer . a reference voltage is applied to the end terminal of the resistor . the terminal connected to the conductive cylindrical wall is coupled to a circuit that converts a voltage across the resistance into a digital voltage that represents the inclination of the clinometer .