ADVANCED DEVELOPMENT MODEL (ADM) SYSTEM 



To evaluate the most promising candidates identified in the state-of-the-art survey (Ref 

 1), the following units were purchased for test and evaluation: 



1. 



Garrett XL500 



2. 



Fisher Pulse 10 



3. 



Fisher Pulse 8 



4. 



White's PI-1000 



5. 



Forster Ferex 4.021 



The Navy MK-10 system was not available for evaluation. A request to the Navy EOD 

 community for loan of an MK-10 indicated that there were relatively few of these units 

 operating. 



The following is a description of the systems purchased for evaluation. 



Elquipment Description 



Pulse-Induced Systems (Garrett XL500, Fisher Pulse 8, and White's PI-1000). Pulse- 

 induced systems operate by intermittently pulsing an electric current into a coil, creating a high- 

 energy magnetic field. When a transmitted pulse encounters a metallic object, eddy currents 

 begin to flow in the metal, which in turn generates a second magnetic field. This field is sensed 

 by the coil, amplified, and then either displayed by a meter or heard in an earphone. 



Figure 2 shows the Garrett XL500. It is supplied with either a 10-inch or a 13-inch coil. 

 The electronics package is detachable so that it can be worn on a belt. Control features include 

 the following: 



1. Detection Depth Setting - A three-position rotary switch for maximum, normal, 

 or minimum output. 



2. Audio volume. 



3. Trash Eliminator - A rotary switch for adjusting the discrimination level. 



The Garrett has both audio and visual output. Headphones are provided for the audio output. 

 A meter located on the electronics package provides visual indication of the signal strength. 



Figure 3 shows the Fisher Pulse 8. It comes with a lO-inch-diameter coil. Detection is 

 indicated to the diver by both a meter and tone (via an earphone). The electronics package can 

 be removed from its holder for servicing or replacement. Control features include the following: 



1. Detection Depth Setting - A three-position rotary switch for selecting high, 

 medium, or low output. 



