Appendix B 

 COMPARISON OF PHYSICAL CHARACTERISTICS 



VISUAL OUTPUT 



Garrett XL500 



POOR. The indication meter is located on the top of the electronics housing, which is 

 either worn around the waist or attached to the top of the sensing wand. Target strength is 

 indicated by an analog meter with scale readings between low and high. In either position, the 

 meter is poorly positioned for viewing. With the housing attached to the sensing wand, the 

 operator must lean forward over the wand and electronics housing to view the meter. With the 

 housing attached to the belt, the operator must twist and bend over at the waist to view the 

 meter. In addition, the meter is not back-lit for viewing in dark or low visibility areas. 



White's PI-1000 



POOR. There are two light-emitting diodes that are located inside the electronics 

 housing. One diode provides a battery check indicator. The other diode indicates the presence 

 of metallic objects by blinking (the higher the frequency of blinking, the greater the target 

 strength). Although these diodes are positioned well for viewing, this form of indication is 

 somewhat ambiguous since the output is qualitative in nature. 



Fisher Pulse 8 



FAIR. The target indication meter is located on the sensing wand and is an integral part 

 of the handle. The meter is adequately sized and positioned well for viewing. However, the 

 meter is not back-lit for viewing in dark or low visibility areas. 



Forster Ferex 



GOOD. Signal strength, battery status, and check indicator for proper operation are all 

 displayed on an analog meter. Although the meter is not submersible, it provides a good 

 indication of target strength and location. This is because the sensitivity of the unit can be 

 adjusted to obtain quantitative readings and the meter swings from one extreme to the other (i.e., 

 positive to negative) when moving over a target. 



B-1 



