The force sensitive resistor is applied to measure the water wave physical parameters. The in–housed wave sensitive actuator was designed and manufactured by 3D printer. By sensing the wave pressure force acting upon the actuator, the voltage signal across the resistor is varied, depending on the water elevations. The voltage signal is amplified and fed to the data logger, and the voltage–time data are obtained as text file and ready for interpreting. The significant wave heights and periods are analyzed manually. These data are validated with the results acquired from video recording photos.
The investigation was carried out by physical model in laboratory. The model consists of 145cm×70cm×16cm wave flume and flap type wave maker. The synthetic wave frequency was fixed at 1 Hz in this investigation. The generated wave progression was recorded by camera, and the wave height was determined from its frame. The observed wave period was estimated by counting number of frames from the defined starting point to the homologous point. The 24 frames rate per second was used during the investigation. With the same setup, the designed wave gauged was placed in the wave flume, measuring the same synthetic wave. The measurement was repeated 30 trials, and its results were compared with the photographic technique using the statistic tools such as standard deviation and t–test.
The experiment results show that the photographic measurement can be served as reference for validation because its dataset indicate small variation in both wave period and height measurement. To validate the wave gauge data with the photo–technique, the t–test was carried out and pointed that the wave gauge data is significant different from the reference; however, from the further investigation, it found that the wave period obtained from the wave gauge was the only parameter which could be validated with the reference due to small variation and range of its dataset. To complete the validation process, the experiment should be revised and modified in the future since there is a hint of irregularity of the synthetic wave because of the side wall reflection; nevertheless, the wave gauge using FSR sensors shows some promising performance to become the proper wave sensor among the others.
