Magnetic Locator vs Pipe/Cable Locator: Which Do You Need?

If you're digging on any site where underground utilities might be present, you need the right locator. But here's where contractors get tripped up: magnetic locators and pipe/cable locators solve completely different problems. Use the wrong one, and you're either missing critical infrastructure or wasting time chasing false signals.

Let's cut through the confusion. Magnetic locators find ferrous metal objects—think valve boxes, manhole covers, iron pipes, and survey markers. Pipe and cable locators track active utilities by detecting electromagnetic signals from cables, pipes, and conduits. Different tools, different jobs.

Side-by-Side Comparison

When to Use a Magnetic Locator

Magnetic locators are your go-to when you're hunting for ferrous metal objects. The Schonstedt GA-92XTd is the industry standard because it's dead simple and bulletproof reliable. No setup, no transmitter to fuss with—just turn it on and sweep.

Common applications:

• Finding property corner markers and survey monuments
• Locating buried valve boxes and manhole covers
• Detecting cast iron or steel water/gas mains
• Finding rebar grids and underground storage tanks
• Pinpointing well casings and septic tank lids

The GA-92XTd gives you depth estimation through its gradient measurement feature. Walk until the tone peaks, mark it, then use the null point technique to pinpoint the exact location. Takes practice, but once you've got it down, you'll locate markers in a fraction of the time it takes to probe manually.

What it won't do: detect non-ferrous metals (copper, aluminum, brass), PVC, concrete, or anything without significant iron content. If you're looking for a copper water line or fiber optic cable, you're barking up the wrong tree.

When to Use a Pipe/Cable Locator

The Ridgid SeekTech SR-24 system handles what magnetic locators can't—tracing active utilities and energized lines. This is critical work for excavation contractors, utility crews, and anyone who needs to avoid striking live infrastructure.

Common applications:

• Tracing underground electrical cables (passive mode detects 60 Hz)
• Following water, gas, or sewer lines with tracer wire
• Pinpointing fiber optic and telecom conduits
• Tracking PVC pipe with attached sonde transmitter
• Mapping complex utility runs before excavation

The SR-24 works in two modes. Passive mode picks up electromagnetic fields from energized cables—no transmitter needed. Active mode uses the companion SR-20 transmitter to induce a signal on a specific line, letting you trace it precisely even in congested utility corridors.

The real advantage here is selectivity. Multiple frequencies (512 Hz, 33 kHz, 131 kHz) let you tune out interference and lock onto your target line. The LCD shows signal strength, estimated depth, and current flow—critical data when you're trying to determine if you've found the main feed or a branch circuit.

The Verdict: Which One Do You Actually Need?

Get a magnetic locator if: You're primarily doing surveying, site layout, or looking for infrastructure access points (valve boxes, manholes). For land surveyors and site prep crews, the Schonstedt GA-92XTd is essential gear. It's also the right choice if you're working in areas without detailed utility maps and need to find old iron mains.

Get a pipe/cable locator if: You're excavating around active utilities or need to trace specific lines. Excavation contractors, utility installation crews, and maintenance teams need the Ridgid SeekTech SR-24. It's mandatory if you're working near energized electrical infrastructure or need to map complex utility routes.

Get both if: You're running a full-service excavation or utility company. Many contractors keep a magnetic locator in the truck for quick marker finds and break out the pipe/cable locator for serious utility work. The tools complement each other—neither replaces the other.

Budget considerations matter too. If you can only afford one tool and you're doing general excavation, start with the pipe/cable locator. It handles the higher-risk scenarios where hitting a live utility could shut down a job or worse. Add the magnetic locator later when marker location becomes a regular bottleneck.

Frequently Asked Questions