Size And Depth Of Buried Objects; Emi - Delta 4000 Owner's Manual

THE BASICS

4. Size and Depth of Buried Objects

When using the detector in the motion DISCRIMINATION mode, the relative
depth of an object is displayed on the right of the display in a 5-segment
format. A more accurate depth reading is available in a no-motion mode,
using PINPOINT mode. Pinpoint displays target depth in inches. Pinpoint
does not require the coil to be in motion to detect metals. The ability to hold
the searchcoil motionless over the target also aids in tracing an outline of
the buried object, or in pinpointing the exact location of the object using
techniques described in the pinpointing section.
5. Electromagnetic Interference (EMI)
The searchcoil produces a magnetic field and then detects changes in that
magnetic field caused by the presence of metal objects. This magnetic field
that the detector creates is also susceptible to the electromagnetic energy
produced by other electronic devices. Power lines, microwave ovens,
lighting fixtures, TVs, computers, motors, etc.... all produce EMI which can
interfere with the detector and cause it to beep when no metal is present,
and sometimes to beep erratically.
The SENSITIVITY control lets you reduce the strength of this magnetic
field, and therefore lessen its susceptibility to EMI. You may want to operate
at maximum strength, but the presence of EMI may make this impossible,
so if you experience erratic behavior or "false" signals, reduce the
sensitivity.
USING HEADPHONES
Using headphones (not supplied) improves battery life, and prevents the sounds
from annoying bystanders.
It also allows you to hear subtle changes in the sound more clearly, particularly if
searching in a noisy location. For safety reasons, do not use headphones near
traffic or where other dangers are present. This device is to be used with
interconnecting cables/headphone cables shorter than three meters.
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