Finding the Fault and the Depth: How Drain Cameras and Cable Locators Work Together
Finding the Fault and the Depth: How TradeTuff Drain Cameras and Leica DD175 Cable Locators Work Together for Complete Pipe Surveys
When a drain blocks, collapses, or fails a pre-purchase survey, there are really two questions that need answering: what is wrong, and exactly where is it, including how deep. A drain camera on its own answers the first question well. It rarely answers the second with any precision, because a camera head pushed 15 metres into a pipe run doesn’t tell you where that point sits relative to the surface above it.
This is the gap that a TradeTuff Drain Camera with sonde and a Leica DD175 or DD300 cable locator close when they’re used together. One documents the inside of the pipe; the other pinpoints the exact surface position and burial depth of whatever the camera is looking at. Paired, they turn a routine drain inspection into a fully located, fully documented survey, which matters enormously to anyone who has to act on the result, whether that’s digging a repair pit, pricing a job, or signing off on a property purchase.
The TradeTuff Drain Camera: Getting eyes inside the pipe
TradeTuff’s drain camera range is built around a self-levelling 23mm CMOS camera head on a fibreglass push-rod, available in 30m, 40m, 60m and 80m cable lengths, feeding 10″ LCD monitor with SD card recording. The self-levelling head keeps the image upright as the camera travels round bends, so footage stays readable rather than spinning with every twist of the pipe, important when that footage is going to be reviewed later or handed to a client as evidence.
Critically for this workflow, TradeTuff’s camera heads are available with a built-in sonde, a small transmitter in the camera head itself that broadcasts a locatable signal through the pipe wall and surrounding ground as the camera moves. That sonde is what a separate cable locator needs to find.
The other feature that matters here is the meter counter built into the reel or display, which tracks exactly how far the camera head has travelled into the pipe.
Between the sonde signal and the meter count, an operator gets two independent pieces of positional information for every point of interest on the video: how far along the pipe it is, and once a cable locator is brought in, where that point sits above ground and how deep it’s buried.
The Leica DD175: Turning a signal into a location and a depth
The Leica DD175 is a multi-frequency utility locator built for the construction and utility-detection market, but it’s equally suited to pairing with a sonde-equipped drain camera.
Relevant features for this use include:
Switching the DD175 into 512Hz sonde mode is exactly what’s needed to hunt for a TradeTuff camera head fitted with a matching 512Hz transmitter. As the operator walks the surface above the estimated pipe run with the DD175, the locator’s signal strength readout leads them directly over the buried camera head, and its depth function then gives a burial-depth reading at that exact spot.
Leica DD175 Locator
How the two work together in practice
1. The TradeTuff camera is pushed into the pipe and the operator reviews the live video feed as normal, noting the meter counter reading at anything of interest î a crack, root ingress, an offset joint, or a full collapse.
2. At that point, the camera head (with its 512Hz sonde active) is left stationary in the pipe.
3. The Leica DD175 is switched to 512Hz sonde search mode, and the operator watches the Signal Strength Indication (SSI) on the digital display rather than trying to judge signal by ear or feel alone. Walking forward over the estimated line of the pipe, the SSI number rises as the locator gets closer to the buried camera head, the highest number found on the display marks the strongest signal, and therefore the point directly above the sonde.
4. Signal strength is not the same as depth, so once the peak SSI position is found, the operator stands the locator directly on the ground at that spot and presses and holds the red button on the DD175 for two seconds. This triggers a dedicated depth reading, displayed on screen in centimetres, giving the actual burial depth of the camera head at that exact point.
5. That surface position and depth reading are logged; either physically marked, GPS-tagged via the DD175, or matched against the camera’s video timestamp and meter reading. Giving you a complete record: what the defect is, how far into the pipe it sits, exactly where it is on the surface, and how deep it’s buried.
The result is a survey that doesn’t just show a problem on a screen, it hands the next person (a digger driver, a quantity surveyor, a homebuyer’s solicitor) a precise dig point and depth, with video evidence to back it up.
Why this combination matters and to whom?
The value of the full data set
What ties all of this together for every one of those audiences is the sheer amount of usable, verifiable information the combination produces from a single site visit:
Individually, a drain camera and a cable locator are established, well-understood tools. Used together, a TradeTuff camera’s 512Hz sonde traced and depth-measured with a Leica DD175, they produce a survey record that is genuinely actionable. Exactly where it is, how deep it lies, and clear visual proof of what it is. That’s the difference between a guess and a plan, for everyone from a homeowner staring at a damp patch on the lawn to a water authority managing thousands of kilometres of buried pipe.
