Figure 21 . Side view of steel frame and polyester mesh sediment trap used at Duck, NC, 

 by Kraus (1987) during CERC's DUCK-85 field experiments 



Electronic instruments are being developed to detect or estimate sediment 

 transport. They have some advantages over direct sampling procedures. 

 These include the ability to measure the temporal variations of suspended or 

 bed-load sediment and the ability to be used in cold water or in harsh 

 conditions. (Note, however, that in severe storms, essentially no man-made 

 devices have survived in the surf zone.) Their disadvantages include the 

 difficulty of calibrating the sensors and testing their use with different types of 

 sand and under different temperatures. In addition, many of these instruments 

 are expensive and not yet commonly available. Sternberg (1989) and 

 Seymour (1989) discuss ongoing research to develop and test new instruments 

 for use in sediment transport studies in estuarine and coastal areas. Acoustic 

 doppler current profilers are being tested and calibrated at CERC to determine 



Chapter 3 Field Data Collection and Observation 



49 



