CD42 Pipeline Pig Location & Tracking System
Page 14
As the operator approaches the location of the stuck pig, the signal will begin to rise on the display
of the receiver. As he walks over the transmitter‟s location within the pipeline, the signals will
peak, and walking further past the transmitter will cause the signal to fall again. This process is
much like watching the passage of a pig as described before under “Pig Passages”, except the
operator passes by the pig instead of the pig passing by the operator.
Once this rough location of the pig within the pipeline has been determined by walking the line, it is
possible to precisely locate the stuck pig to within just a few inches by using a “nulling” technique.
For a discussion of nulling, please refer to the more detailed section on locating pigs entitled
“Pinpointing a Pig‟s Precise Location” beginning on page 56.
Conclusion
We believe that, although brief, this section gives you a quick jump-start on how to use the CD42 Pig
Location and Tracking System to successfully track and locate pigs. The process is actually fairly
simple and straightforward, and requires only a modest amount of time to learn.
The remainder of this manual is dedicated to explaining in greater detail the more advanced aspects of
the CD42 system, and should be read by anyone who plans to use the system for long periods of time,
or who needs or wants to use some of the system‟s more advanced features such as recording and
printing pig passage data.
