THE SAND IMPACT PROBE (SIP) IS A SENSOR WHICH MEASURES THE CONCENTRATION OF SUSPENDED SAND BY REGISTERING THE IMPACT OFMOVING GRAINS ON A TRANSDUCER.

THE SAND IMPACT PROBE (SIP) IS A SENSOR WHICH MEASURES THE CONCENTRATION OF SUSPENDED SAND BY REGISTERING THE IMPACT OFMOVING GRAINS ON A TRANSDUCER. PREVIOUS WORK HAS SHOWN THATTHE UNI-DIRECTIONAL SIP IS A PRACTICAL INSTRUMENT, BUT (A) ITS UNI-DIRECTIONALITY PRECLUDES USE IN REVERSING OR MORE COMPLEX FLOWS, I.E. IN THE SURF ZONE; AND (B) ITS SIZE LIMITS USE CLOSE (WITHIN CENTIMETERS) TO THE BED. THE PROGRAM OBJECTIVES ARE: (1) TO DESIGN SENSORS SUITABLE FOR APPLICATION IN COMPLEX FLOWS AT ELEVATIONS 10 CMS AND HIGHER ABOVE THE BED: CAPABLEOF DETECTING IMPACTS PRODUCED BY SUSPENDED GRAINS IN THE SIZE RANGE 90 M -- 1000 M) MOVING AT VELOCITIES OF 0.2 MS-1 TO 1.0 MS-1. (2) TO DESIGN SENSORS SUITABLE FOR APPLICATION CLOSE TO THE BED, FOR SIMILAR OPERATIONAL GRAIN SIZE AND VELOCITY RANGES AS IN OBJECTIVE (1). (3) TO FABRICATE AND EVALUATE PROTOTYPES RESULTING FROM DESIGN OBJECTIVES (1) AND (2) THAT ARE FEASIBLE TO CONSTRUCT. THE IMPLICATIONS OF THIS INSTRUMENT ARE FAR-REACHING IN THE COMPLEX FIELD OF SAND TRANSPORT. BOTH IN BASIC LABORATORY (FLUME) RESEARCH AND FIELD STUDIES BY UNIVERSITIES, AND IN FIELD APPLICATION BY USERS SUCH AS THE CORPS OF ENGINEERS, WATERWAYS EXPERIMENT STATION (WES), AND COASTAL ENGINEERING RESEARCH CENTER (CERC).