From the magazine

The changing face of pipe and cable location

In today’s market, customers have many choices when it comes to locating services on the job site.

The range and number of choices can at times be confusing, but it doesn’t have to be, thanks to this handy review of some of the equipment available.

Multi-array pipe locators

The UtiliTrac, manufactured by Sewerin, uses six antennas to pick the electro magnetic field (EMF) around pipe and cable. This is the same way any EMF-based locator works, but the UtiliTrac is different in the way it displays the location of the pipe. This particular unit uses all six antennas to locate the position of the magnetic field in relation to the receiver; this gives the operator an indication of the pipe via a line. This has made locating very simple even for the novice operator.

Some of the unique features on this unit are a single trigger button that operates all of the controls, full automatic gain and depth. The UtiliTrac is also unique in that it has six passive modes. Of the six passive modes three are set for the different types of power; a new update from Sewerin will increase this to four passive modes for power (this was done after testing with one of the major power authorities in Australia). The unit also has a large selection of frequencies available.

Locating modes

What makes this unit a good choice for infrequent users, as well as professionals, is its multitude of locating modes. Line mode is by far the easiest mode to use and makes locating very quick. This mode cuts locating times down as the operator does not need to swing the locator from side to side, and can literally walk down the road at a reasonably quick but safe speed. In the line mode there is no need to adjust gain or press a depth button – you simply follow the line and centre it for depth. For professional operators the unit also features a handy peak+ mode which gives the locator the level of accuracy required to compare with the more traditional unit. The unit also comes with the traditional peak and null modes which professionals use every day for added accuracy. The UtiliTrac displays signal strength of the cable, which assists in identifying cable coupling or ghosting. The unit has several sonde/camera modes which again makes locating these types of accessories easy.

Passive modes

Having more than one passive power mode is very advantageous as some power modes work better on single-phase cables and others work better on three-phase power supplies. This unit even has a mode for dirty power which can sometimes effect passive power modes. The unit has its traditional RF and CPS passive modes which can be selected or deselected as needed.

Automatic gain and depth

This unit has a full automatic gain. The advantages of the auto gain is the simplicity of use and the fact that it is both fast and is always monitoring signal strength. Auto gain has its disadvantages as well, and years ago, locators with automatic gains were not ideal, as they would often jump onto other services due to the gain being oversensitive. As a result, inexperienced operators would sometimes inadvertently locate the wrong service. It also takes control away from the operators – something that professional operators dislike.

Another feature of the UtiliTrac is the automatic depth. Automatic depth is displayed once the locator comes into maximum range. The beauty of the UtiliTrac auto depth compared to its competitors is it also displays the depth accuracy (online mode) via a numeric value, giving the operator the ability to determine how accurate the depth is. Like all machines, depth should be used as a guide only as other factors can cause depth errors.

These features help the operator to locate more precisely with less training to give reasonable and accurate locates, but these machines still require a level of training to understand the functions. Access Detection provides full professional training for the UtiliTrac.

Traditional locators

Some operators still work on manual control, so if an operator wants to use equipment that has these functions, traditional locators like the Radiodetection and Rycom units are good options.

One new unit that has just been updated is the Rycom 8879PLS. This unit offers incredible value and the new 5 and 10 watt transmitters are extremely powerful. The good thing about the Rycom unit is it has kept things simple. It has no fancy functions; no coloured screens with lots happening at once, just the traditional peak and null modes, full manual gain, and depth and current measurement. These functions, while sometimes feeling a bit old fashioned, offer all that is needed for an accurate location.

Ground-Penetrating Radar

Ground-Penetrating Radar (GPR) is probably one of the most misused pieces of technology used by locators. Most professional locators will understand that GPR is an essential add-on tool for locating services that the traditional locator may struggle with. The most common areas GPR is used is in heavily congested areas, and around unknown services, non-metallic services and deep services. GPR is a vital piece of add-on equipment for the professional locator, but in the wrong hands, or when used as the only locating tool, it can be detrimental. GPR is an expensive investment and should be researched thoroughly before a decision to purchase is made.

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