With all new construction or pipeline deviation, the rise in one-call excavation has increased proportionately with the need for damage prevention. Locators must be diligent in the accuracy of their locations due to the increasing maze of underground utilities, and threats from liabilities and lawsuits.

Damage prevention programs help operators maintain pipeline integrity and operator qualifications. Locator training classes are providing operators with the tools they need to perform an accurate locate. Part of those tools, of course, is the instrumentation that is needed to locate facilities accurately.

Locating technology has come a long way from the willow stick or welding rod. Prior to the 1980s, the locating instrument was fairly one-dimensional. A two piece split box type locator that gave you a peak or null signal, along with the analog meter, was the only indicator you had in determining if you were locating your facility. The locator back then – and those who are presently still using this “old” style instrument – spent many a day bent over getting that peak/null signal to tune in just right.

Starting in the early 1980s, the development of the micro-processor made locating easier. There is now a three dimensional (3D) instrument providing three pieces of vital information: signal power indicator (SPI), left/right indicator and continuous depth readings.

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The largest advantage the advanced locator has over the split-box locator is the SPI numbers. The SPI numbers are arbitrary numbers that indicate to the operator the amount of electromagnetic field strength the receiver is picking up from the conductor. The SPI numbers let an operator know how strong of a signal the receiver is picking up and how the operator can use this information to judge the quality of the locate. The numbers can aid in differentiating between the facility the operator is trying to locate versus a facility that could be interfering with the signal.

The left/right indicator is a directional arrow with special tones to guide the operator to the location of the facility. When the receiver is positioned directly over the conductor, the speaker will null (produce no sound).

The continuous depth function provides the operator a constant picture of the estimated depth of the facility while locating. The operator is able to see any significant changes in depth immediately. Unexpected estimated depth readings alert the operator of potential factors which may affect locating accuracy.

In addition to the above features, the advanced locators provide multiple frequencies, ranging from 500 Hz to 480 kHz. The ability to switch between frequencies provides an operator with the added ability to isolate a facility. Experience has shown that the lower the frequency the better chance there is of a signal not “bleeding” off to another conductor, especially when locating in a congested area. Also, if an operator’s job is to locate many different type of facilities, they have the ability with a multiple frequency locator to choose that frequency that will work best on a particular facility.

Companies now have many tools, as well as instrumentation and training, available to them in the fight to prevent damage to buried facilities. It is just a matter of utilising these options effectively for the optimum results.