Abstract: The device senses the level of a float which may rest on the surface of the liquid whose level is to be determined or may rest on the surface of liquid (e.g., mercury) of a manometer which measures the level of liquid in accordance with the purge bubble principle. The fluctuation of the float turns a pulley which causes oscillatory movement of an arm carrying a magnet. In proximity to the path of the magnet is a board carrying radially disposed, angularly spaced reed switches. As the magnet passes each switch it closes same and passes a signal to a digital accumulator. A slip clutch between the arm and a second arm causes the latter to oscillate in the same direction as the first arm, but only for a limited distance. The second arm also carries a magnet which changes the direction of a second reed switch and dampens hunting of the first series of switches by preventing activation of the accumulator except when the second reed switch is closed.