The Megger 656902 Split-box Pipe and Cable Locator is a hand-held instrument in the classic "split-box" design, consisting of a transmitter and a receiver. The instrument traces underground conductive networks such as water and gas mains, telephone, cable TV, and electric power cables. It determines buried lines depth and locates underground metallic masses such as valve caps and manhole covers.
Designed with patented super-inductive technology, the Split-box Pipe and Cable Locator is lightweight, portable, and easy to use. For easy transport, the instrument and accessories are supplied with a protective tote bag.
To locate and trace an underground metallic line, the line is energized with a radio-frequency signal generated by the transmitter and then detected by the receiver. Inductive or conductive modes of operation are available.
The inductive operational mode does not require direct mechanical line connection. The transmitter can energize a buried line without the need to uncover it. Just place the transmitter on the ground or pavement above the line which, once induced with the transmitted signal, retransmits the signal through the ground and air in a pattern that corresponds to its path. The line carries the signal several hundred yards depending on its depth, the mineralization and conductivity of the soil, and the transmitter power setting.
The conductive mode of operation requires the line to be exposed so that a direct connection can be made. Conductive energizing is preferred over inductive energizing because it results in more highly defined signal coupling. The signal generated does not spread to other conductive lines in the vicinity of the traced line. Using a ground rod with the direct connection increases the energizing efficiency and, therefore, the length of line that can be traced.
Two methods of receiving the transmitted signal are peak detection and null detection. The method used depends on the placement of the receiver. When held at a right angle to the surface of the ground and moved back and forth across the line to be traced, the receiver detects peaks (maximum signals) when directly above the line. When the receiver is held so its face is parallel to the surface of the ground and moved back and forth across the line, the detection of minimum signal or null (absence of signal) indicates that the line is directly below.
Applications
To trace and locate underground metallic lines, the lines are energized using a radio frequency generated from the transmitter & detected with the receiver. Conductive or inductive operational modes are available.
The operational inductive mode doesn't require a direct mechanical line connection. The transmitter energizes buried lines without uncovering them. Simply place your transmitter on the pavement or ground above the targeted line, and once it is induced with a transmitted signal, re-transmits that signal through ground & air with patterns that correspond to its path. Underground lines carry the signal for several hundred+ yards (dependent on depth, soil conductivity and mineralization, & transmitter power settings).
The operational conductive mode requires lines to be uncovered so direct connections can be made. The conductive energizing method is preferred to energizing inductively because the signal coupling results are highly defined. Generated signals don't spread to adjacent conductive lines. The traceable line length may be increased with a ground rod and a direct connection.