Underground Utility Location Equipment ExplainedLocation Equipment thats used to locate underground and buried utilities such as water lines and cables is an interesting subject. Whether you're a newbie or a seasoned professional, taking time to learn about the art of locating things underground takes many years of experience and in most cases, proper training. First, I will explain the various location equipment that we represent and sell here at EngineerSupply. We basically sell two types, one being magnetic locators, and the other being pipe/cable location equipment.
Magnetic locators are primarily used for locating a single point such as a property corner pin made of rebar or water pipe. Magnetic locators basically locate anything that a magnet would stick to, hence "magnetic locator". What does a Magnetic Locator find? Can it detect an electric line, a water line? It can detect any ferrous (iron/steel) object that is isolated, such as a steel property pin, steel manhole cover, steel water or gas valve. A magnetic location should not to be used or preferred for buried utility detection, as a pipe & cable locator is the appropriate instrument for these applications.
The number one question we get is how deep can can a Magnetic Locator detect? The range of a magnetic locator, relative to the size, orientation and mass of the iron/steel object is capable of detecting a large steel object like a 55-gallon drum at 15 feet deep. Most magnetic locators that we sell are sold to land surveyors that use them to locate property corners, aka "pins", made of rebar and pipe. Other items located by magnetic locators are cast iron valve and meter boxes, as well as ductile iron water pipe and underground storage tanks. Some locators are used by the military when looked for unexploded ordinance. The brand that's most known is the Schonstedt brand of locators and seem to be the most popular. CST/Berger makes a very nice locator that they call the "Magna-Trak" which is also widely known and used within the industry. If you want to know who makes the "best magnetic locator" on the market, that's a matter of opinion.
Can the magnetic locator find any kind of metal, is it a metal detector? No, the instrument is specifically for detection of objects with iron/steel (ferrous) content. It ignores all other metals, including aluminum, copper, brass, coins and precious metals like gold. Magnetic Locators are not the kind of "metal detector" you see used at the beach as those are more or less sonar type which detect objects by sound and not necessarily metal.
Pipe and Cable Locators
Pipe and Cable Locators are the second type of utility location equipment we sell that's used for location of underground buried utilities. Pipe and Cable Locators in their basic form are two parts, one is a transmitter, and the other being a receiver. The transmitter part is used to induce a signal onto a pipe or cable and then the wand, or receiver, is used to locate the signal that the line is producing.
Can it find electric, cable TV, telephone, water or gas pipelines and tracer wire? Yes, any buried utility that is of metallic construction and linear and preferably grounded to earth along the path or end-points can be located by any instrument called a pipe & cable locator.
Does it locate plastic (or any non-metal utility)? No, the utility must have a metallic linear property for the signal of the
locator to transmit down. However, if there is a tracer wire buried alongside or included with the non-metal utility, this is
metallic and therefore able to locate. Sometimes a metallic linear device like a plumbers snake or electrical fish-tape can be inserted inside of the non-metal pipe and located by applying the signal to this inserted device.
What is the best choice of pipe & cable locator when I work in urban areas where there are many utilities underground and nearby? It is preferred to use a multi-frequency mode Pipe and Cable Locator. By having a choice of frequencies and power adjustments, this provides ways to isolate the utility from others and reduce interference.
What does a Pipe and Cable Locator come with? Most basic models includes a transmitter, a receiver; ground stake and conductive (direct-connect) clips to apply the signal to the utility directly.
Can the Pipe and Cable Locator locate power lines without using the transmitter? Yes, but this method called Passive or 60Hz locating is not fool-proof and is not the preferred method by the Dig-Safe or 811 society. The power line must be energized and have a significant “load” to have the chance of detecting the presence of 60Hz. Plus other buried utilities such as gas pipeline, telecommunications cables and event water and sewer lines can have the ability of carrying the 60Hz signal onto them indirectly.
Hopefully our article helps explain the differences between the two location equipment products we represent and sell. One of the best ways to get started is buy a locator and start using it to locate. Over time you will develop listening skills and a technique that helps you locate as well as be able to estimate the mass and depth an item is. While magnetic locators are fairly straight forward and easy to learn and use, Pipe and Cable Locators take some time to get the experience one needs when locating utilities. Over time you'll learn to rely on what you're locating and feel confident with using the equipment. In regards to brands and models, you can browse our website as well as give us a call during business hours. We'll be glad to help explain which brands are higher quality than others, as well as discuss each models features. - EngineerSupply Team