Figure 5. Current meter mount with meter installed 



conditions, and current characteristics. An adjustable collar on the tripod 

 holds the metal cylinder housing the meter electronics and preamplifier, 

 allowing vertical adjustment of the current meter sensor. The flow meter 

 sensor was placed 20-30 cm above the bed in all deployments. The horizontal 

 axis of the current meter was aligned with its y-component parallel to the 

 trend of the shoreline. The current meters sampled at 4 Hz and typically 

 recorded for a nominal 30-min period which included the sand-trapping run. 



Sand transport rate 



21. The longshore sand transport rate was measured by means of portable 

 traps such as shown in Figure 6. The sand collection element of the trap 

 consisted of a metal frame or nozzle to which a cylindrical bag of flexible 

 filter cloth called a "streamer" was attached. The polyester monofilament 

 cloth allowed water to pass through but retained sediment of nominal diameter 

 greater than the 0.105 -mm mesh, which encompasses sand in the fine grain size 

 region and greater. The concept of the streamer- type trapping device for use 

 in the nearshore was introduced by Katori (1982, 1983). Development of the 

 trap has continued at CERC, including mounting of the streamers on various 



17 



