SubSurface Leak Detection Inc

- Model LD-15 - Professional’s Leak Survey Instrument



The new LD-15 Professional’s Leak Survey Instrument offers the highest sensitivity and the best audio quality ever offered in an acoustic listening device by our company.

  1. Amplifier with Meter Display and Filter Controls
  2. Padded Case and Standard Belt (40 inches)
  3. High Sensitivity Sensor and Cable
  4. Base Plate for Listening on Street Surfaces
  5. Aviation-Grade Stereo Headphones
  6. Heavy-Duty ABS Plastic Carrying Case

  • 40 inches Long Contact Rod (not shown)
  • 60 inches Long Contact Rod (not shown)
  • Large Size Belt (50 inches)
  • Extra Large Size Belt (60 inches)

High sensitivity sensor with Neodymium magnet (extra strong). Sensor and cable connection completely sealed and water-proof (submersible).

Amplifier with superior audio quality (very low distortion and superior signal-to-noise ratio) and large meter display. Press the Mute Switch to hear sounds when you are ready.

“Survey” for water leaks by listening at hydrants and valves with the sensor and magnet. Survey at water meters with a Long Contact Rod (optional).

“Pinpoint” water leaks in pipes under asphalt or concrete with the base plate attached to the sensor and magnet.

Use the High filter range for water leak surveying. Use the Low filter range for water leak pinpointing. High frequency leak sounds travel on the pipes, but only low frequencies pass through the soil.


  • Amplification : 56 dB
  • Filter :
    • High Range Ranges 30 Hz to 5000 Hz
    • Low Range   30 Hz to 800 Hz
    • Notch Filter   150 Hz, 180 Hz
  • Power: 4 C dry cell batteries
  • Battery Life: 80 hours with alkaline batteries at 68 degrees F
  • Weight: 31 ounces (including 4 C batteries)
  • Size: 6.4' x 3.0' x 5.7'  (163mm x 76mm x 144mm)


  • Sensitivity: 10 V/g
  • Resonance Frequency: 950 Hz (±150 Hz)
  • Weather Protection: IP68 or equivalent (3 ft under water for 3 hours)
  • Cable Length: 9.75 ft

The sounds of leaks in pressurized water pipes can travel for hundreds (even thousands) of feet in every direction down the mains and services. If there is no evidence of the leak, then compare the loudness of the leak sounds at the meters, valves, and hydrants:

When you have found the two meters, valves, or hydrants with the loudest leak sounds, you are ready to begin the final “pinpointing”. First, mark the exact location of the pipe between the two loudest valves, meters, hydrants, etc. with a pipe locator. Then listen every 2-3 feet directly over the pipe.

Different pipe materials and different pipe diameters transmit leak sounds down their pipe walls very differently:

Water leak surveying at meters is often performed using a long contact rod:

Use your hearing and the meter display to determine exactly where the leak sound is loudest:

For water leak pinpointing, attach the base plate to the sensor’s magnet and listen directly over the pipe:

Listen and move the sensor every few feet directly over the pipe.

Press the Mute Switch only when the base plate is sitting firmly on the street.

The Long Contact Rods are NOT digging bars or probe rods. The sensor can be broken if the rod is pounded into the ground.

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