Underground Utility Location Equipment Explained

Location Equipment that's 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.

Underground utility location equipment explained

Magnetic Locators
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 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 seems 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 detects 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.

Underground utility location equipment explained

What does a Pipe and Cable Locator come with? Most basic models include 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 to carry the 60Hz signal onto them indirectly.

Summary
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 to 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 model's features. - EngineerSupply Team

Utility Locator Infographic

Frequently Asked Questions

Is It Possible To Locate Underground Utilities?

It is entirely possible to figure out where utility lines are on and around your property! A utility locator is a handy piece of equipment that can read terrain and give you an idea of what lines might be present. Ordering this tool is quick and easy, making your entire experience a straightforward one.

What Are Examples of Underground Utilities?

Utility lines are found both above and below the ground. An underground utility locator can be used to find water pipes, sewer lines, sprinkler lines, fence wiring for pet shock collars and more. Most of these utilities will be directly connected to your building or units that connect your lines to main lines.

Can I Just Dig Anywhere For Utilities?

Even though it is your property, you definitely need to exercise caution when it comes to digging. In most states, there is a “call before you dig” mentality. This means you need to get in touch with your local government before you use your utility locator to make any deep holes that could run into major power, gas, or water lines.

Do I Need To Make a Call If I’ve Dug Before?

There is a popular misconception that you don’t need to contact the right authorities before using a utility line locator and breaking ground if you’ve already dug on your property in the past. This is not true. No matter how many times you’ve dug before, you still need to make a call in order to inform the right channels.

Does It Matter How Deep I Need To Dig?

Whether you’re using your utility locator to dig a few inches or a few feet, you still need to take proper precautions. Utility lines can shift position over the years due to erosion, changing weather patterns, and other environmental factors. Always err on the side of caution and be sure to take proper precautionary measures.

Best Pipe Locators

#1: Pipehorn 800HL Dual-Frequency Pipe & Cable Locator

This dual-frequency underground utility locator is always recommended over Pipehorn’s single-frequency model. Because it has the 9kHz frequency that’s needed to find utility lines buried deeper underground, it has the range you need to find a number of underground pipes and cables. With its superior high-frequency performance, it's one of the best utility location tools in the industry when direct connect isn’t possible. And for the toughest conductors (such as coated iron pipes with insulated joints or street and parking lot lights), nothing else will sweep an area for unmarked utility lines than this utility locator.

SHOP Pipehorn 800HL

#2: Schonstedt REX - Multi-Frequency Pipe & Cable Locator

This multi-frequency pipe locator by Schonstedt is a great choice for the working professional, because it has the following features:

The transmitter is less than 2 inches thick and weighs less than 4 pounds.
The entire unit fits easily into a custom storage bag.
The receiver and transmitter together weigh under 7 pounds for an ultralight design.
The receiver can retract for easier carrying.
Capable of 512 Hz, 33 kHz, and 82 kHz frequency detection.
Capable of 50/60 Hz passive and 512 Hz sonde detection.
The transmitter comes with rechargeable batteries.

This unit is built for utility professionals in the water, sewer, gas, electric, and telecommunication industries.

SHOP Schonstedt REX

#3: Pipehorn 800H Single-Frequency Pipe & Cable Locator

With the ability to detect frequencies of up to 480 kHz, this pipe locator can find utility lines that are buried down to 18 feet deep (depending on the type of connection, the condition of the soil, and how well it can conduct the signal). It also has a fast-response signal strength and a sharp audio tone that allows for precision pinpointing. And with a watertight reinforced receiver wand, it's incredibly durable. The transmitter has a high-impact ABS housing that’s bright yellow, so it’s easier to see.

SHOP Pipehorn 800H

#4: Schonstedt Loki Utilities Multi-Frequency Pipe and Cable Locator

This utility locator is perfect for “sweeping” a large area to find buried assets quickly and easily. The Schonstedt Loki has a number of features that support the quick and easy detection of underground utility lines. Some of them include but may not be limited to:

The 512 Hz frequency can be used to trace metallic pipes, while the 82 kHz frequency can find hard-to-locate jointed pipes.
The simple mode selection matches the device to the signal type you need to locate.
The Sonde Mode can find a signal being transmitted by a compatible sonde.
The Transmitter Mode can find transmitter signals being imposed on buried utilities.
The Power Mode can find the electromagnetic fields being generated by loaded power cables.
The Dual Mode simultaneously searches for and identifies transmitter and power signals for quicker sweeps.
The ShallowAlert feature will warn you of the possible presence of shallow cables and utility lines in every mode.
The NoiseProtect feature allows you to use the device in areas that are electrically noisy.

Be sure to pick yours up at Engineer Supply today!

SHOP Schonstedt Loki Utilities

#5: Schonstedt Loki Contractor Multi-Frequency Pipe and Cable Locator

With a receiver that weighs 4.9 pounds and a transmitter that weighs 4.0 pounds, this unit is a lightweight tool that’s perfect for finding pipes, cables, and underground utility lines in large areas. It also has a IP54 rating, which makes it resistant to water and dust. The transmitter has a built-in speaker that generates an audio signal, which can be heard over road traffic. The receiver also has a detachable speaker that can double as an earpiece.

If you’re looking for an underground utility locator to help you find buried pipes and cables, be sure to look at what we have at Engineer Supply.