White’s Electronics TM 808 - Manual (Page 16)

TARGET
DEPTH
EQUALS
TARGET DEPTH
NOTE: This method produces
approximate depths of deep
targets. It may not work well
on shallow large targets.
TARGET SOUND
BEGINS
METAL
TARGET
PINPOINT MARKS
TARGET CENTER
(16)
Determining Metal Depths
Once the center of a target has been pinpointed, and marked, the
approximate depth it is located in the ground can be determined by using the
following triangulating method.
1) Move off to one side of the pinpointed target center mark.
2) Set AUTOMATIC THRESHOLD to the NO-AUTO position.
Press and release the PUSH BUTTON on the handle, while
holding the instrument at arms length.
3) Move directly toward the pinpoint mark stopping when the
target first begins to respond. At this point the distance from the
center of the front loop or antenna, to the pinpoint mark, is the
approximate depth the metal is located in the ground.