5.9.2 Copper pipes
A non-ferrous metal object, e.g. a copper pipe, is within
the sensor area. It lies at a depth of approx. 4 cm (1.6 in).
The tool emits a signal tone.
5.9.3 Plastic or wooden objects
A non-metallic object is within the sensor area. The object
is made of plastic or wood (or is a cavity) and lies close
to the surface. The tool emits a signal tone.
5.9.4 Live electric cables
NOTE
Depending on the size and depth of the object, it is not
always possible to determine without doubt whether it is
live (i.e. carrying electricity).
NOTE
When scanning, do not lay your hands on the surface of
the material.
NOTE
Live cables can be detected more reliably when the
scanner is moved slowly.
A live metallic object, e.g. an electric cable, is within the
sensor area. It lies at a depth of approx. 1.5 cm (0.6 in).
The tool emits a warning signal tone for "live cables" as
soon as the electric cable is detected by the sensor.
5.9.5 Objects with a large surface area
A metal object with a large surface area, e.g. a metal
plate, is within the sensor area. It lies at a depth of
approx. 2 cm (0.8 in). The tool emits a signal tone.
5.9.6 Unclear signals 4
If a very large number of objects are shown it is possible
that the wall contains many cavities (e.g. hollow brick)
or the scan has been made along the length of a long
object.
NOTE
By making additional scans parallel to the first scan,
above and below, and marking the position of any objects
detected, it is possible to determine the course followed
by long objects. Offset marks are an indication of cavities.
NOTE
In the "Hollow brick" scanning mode, cavities are filtered
out to a great extent (i.e. not shown).
en
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