A Portable Recording Tide Gauge

Abstract

The gauge is pressure-operated. A copper bellows is connected by plastic tubing to the water, and both bellows and tube are filled with water. Movements of the free end of the bellows are transmitted through a lever system to a marker recording on a revolving drum. The weight of the water is counterbalanced by suspending appropriate weights from the free end of the bellows. Waves are damped by inserting a capillary in the tubing. The instrument records on a scale of 1 in, to 1 ft (the maximum tidal range on the coast of south-western Australia is 5 ft) and it is sensitive to changes of water level of less than 1 in. It is readily portable.