Optical wave measurement technique and experimental comparison with conventional wave height probes.

An optical system developed to measure wave slope is described. When the phase speed of a wave train propagating in a single direction is known, the measured slope can be integrated to give wave height directly. Results obtained under these conditions are compared with those from a capacitive wave height probe and demonstrate the accuracy of the system. These experiments also indicate a rather severe limitation of the wave height probe due to a lack of spatial resolution because of the mensicus on the probe. Confirmation is also given that the correct value of surface tension to use in the wave dispersion relation can be obtained from a static measurement, in this case by a du Noüy tensiometer.