7. Carrying Bag.
There are two kinds of carrying bag available for the 902
locator, both constructed from rugged nylon canvas. The
smaller bag comes with the instrument originally and con-
tains only enough room to carry the instrument and its basic
set of accessories. The larger bag has additional pouches
specifically tailored to house the GC-2 cable clamp, a set of
headphones, and other miscellaneous items. The larger bag
is sold separately.
C. Modes of Operation:
1. Transmission Modes.
There are two modes of signal transmission for the Model
902 Pipe and Cable Locator: inductive and conductive. Two
discrete output levels may be selected for either mode, and
the operator may choose to pulse the signal in either mode
of transmission for easier identification.
a) Inductive Transmission. In inductive mode, the 902 trans-
mitter produces a radio signal capable of penetrating air,
ground, and other media in order to energize a nearby
conductive line. Having been effected by the transmitted
signal, the line then conducts the signal along its path.
The signal pattern surrounding the line corresponds to the
path of the line itself. Therefore, the operator may use the
902 receiver to trace the direction of the line and to
determine its depth from the signal pattern surrounding it.
Although energizing a line inductively can be convenient
and sometimes necessary, this method typically is less
precise than conductive transmission in its ability to
isolate a desired line.
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