10x1 0-f t water 

 filled tank 



Sonar "Targets 



Q) 6-in. crescent 

 wrench 



(g) 3-in. OD sphere 



(^ flathead screw, 

 8-32, 1/4 in. long 



1.5-in. OD water- 

 filled PVC pipe 

 running diagonally 

 down inside of 

 tank 



tank wall (normal 

 incidence) — path A 



bottom corner 

 of tank — path C 



AGS transducer 

 position 



PVC pipe ■ 

 path B 



Figure 18. Interpretation of AGS display. (From Reference 20.) 



69 



