investigated. The ocean tests were performed to verify performance under operational conditions 

 and to identify any safety or human factor deficiencies. 



Laboratory Tests. The objective of the laboratory tests was to verify the detection 

 thresholds specified in the TEMP. Table 7 lists the TEMP detection thresholds for SD List 5 

 cable, armored Simplex Pipe, 1.5-inch chain, and a 6,000-pound anchor. 



Table 7. Vertical Detection Distances 



Target 



TEMP 



Detection 



Threshold (ft) 



Detection Threshold (ft) 

 Sensitivity Level (gamma) 



1 



3 



10 



30 



100 



300 



1000 



Pipe (5-inch) 

 Simplex with 

 Armor 



2.5 



- 



- 



- 



4.0 



2.9 



1.7 



- 



Chain (1-1/2- 

 inch) 



6.0 



6.1 



6.0 



5.1 



3.9 



2.4 



- 



- 



Anchor (6,000 

 Pounds) 



10.0 



- 



10.0 



9.4 



5.9 



3.6 



- 



- 



Cable (SD List 

 5) 



3.0 



- 



6.0 



5.0 



3.5 



3.0 



2.1 



1.0 



In theory, the sand or water covering a buried ferromagnetic object should not greatly 

 affect the detection distance (provided this covering has a relatively undetectable magnetic 

 signature of its own). To verify this, the detection thresholds for an SD List 5 cable section 

 (about 7 feet long) and 3/4-inch chain were measured while they were buried in sand and lying 

 on the beach surface. 



The results of this test confirmed that the individual detection distances of the SD List 5 

 cable and the 3/4-inch chain were the same whether the objects were buried or lying on the sand. 

 The detection threshold for both the buried and unburied cable was 36 inches with the tool set 

 for a sensitivity of 100 gammas. The detection threshold for both the buried and unburied chain 

 was 20 inches with the tool set for a sensitivity of 100 gammas. 



Based on the above results, the detection thresholds for the buried objects listed in the 

 TEMP were determined in the laboratory by measuring the vertical distance between the probe 

 and the object with the object lying on a bed of sand. These tests were performed by lowering 

 the probe direcUy over the target for each sensitivity level until a half-scale deflection of the 

 meter was observed. The vertical distance between the probe and the target was then recorded 

 for each sensitivity setting. 



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