An instrument for field measurement of wave impact pressures and seawater aeration

Two new transducers have been developed and combined into an instrument for the simultaneous measurement of wave impact pressures on steep fronted coastal structures and the level of aeration in the seawater striking the structure. Design criteria for the new pressure and aeration unit are discussed. A description is given of the new transducers together with a purpose-designed data acquisition system that serves seven of the units, a video camera to record breaker shape, and an accelerometer to record the structure's response to the applied loading. Performance of the new instrumentation is illustrated with examples of measurements obtained from an exposed breakwater at Alderney in the Channel Islands. The complete system operates automatically requiring only routine change of batteries and data tapes.

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