SubSurface - Model LD-8 - Leak Survey Tool
From Water Leak Detector
The new LD-8 Leak Survey Tool is designed specifically for “water leak surveys” done by water departments, water districts, and other government and private agencies concerned about “unaccounted-for water losses.”
- Heavy-Duty ABS Plastic Carrying Case
- Over-the-Ears Stereo Headphones
- Amplifier with Display and Volume Control
- Short Contact Rod (4 inches)
- 4-Section Contact Rod Set (52 inches)
- Optional 40 inches Rod (top photo)
- Optional 60 inches Rod (not shown)
- Instruction Manual (not shown)
Amplifier with push button ON/OFF switch, volume control, two-digit display of loudness, and three-range sensitivity switch.
Use the short contact rod for listening at hydrants.
Use the long contact rods for listening at below-grade meters and below-grade valves.
Notch filters reduce A/C hum from transformers, power lines, etc.
Excellent sensor sensitivity, leak sound amplification, and audio clarity.
Stereo headphones with soft leather ear covers are comfortable for hours and hours.
Use the two-digit display to compare the loudness of leak sounds at nearby locations, like adjacent water meters, close water hydrants, close water valves, etc. The display can show which is loudest when your ears can not tell.
Sturdy, light-weight carrying case weighs only 10 lbs. and fits behind the seat in the truck.
- Sensor: Piezoelectric Element
- Amplification: 55 dB
- Frequency Range: 100Hz to 2000Hz
- Notch Filters : 150Hz and 180Hz
- Temperature Range: 25 F to 130 F
- Batteries: Two AA
(dry cell or rechargeable)
- Battery Life: 24 hours minimum
- Weight: 10.6 ounces (with batteries)
- Size: 8.15 by 3.3 by 2.4 inches
- Stereo, 8 ohms
ABS CARRYING CASE
- Weight (full): 10 lb.
- Dimensions: 18 by 11.5 by 7 (inches)
STANDARD CONTACT RODS
- Short Rod : 4 inches, anti-slip tip
- 4-Section Rod : 4 sections, each 13 inches, threaded connections
OPTIONAL CONTACT RODS
- 40 Inches Rod : Single piece, light-weight stainless steel
- 60 Inches Rod : Single piece, light-weight stainless steel
The sounds of leaks in pressurized water pipes can travel for hundreds (even thousands) of feet in every direction down the mains and services:
Different pipe materials and different pipe diameters transmit leak sounds down their pipe walls very differently:
The service line material is also very important when listening at meters or curb stops:
The leak survey “strategy” must consider the pipe materials, pipe diameters, service line materials, and types of leaks expected.
If the distribution system experiences main breaks (5 to 10 gal/min or more) at certain times of the year and the mains are iron pipe or A/C pipe, then a “Hydrant Survey” can be effective and an efficient use of time. Listen at every hydrant in every block. If there is no hydrant for 500 ft., then choose a main valve.
If the distribution system has PVC mains and copper services, then an “Every Meter and Every Valve Survey” may be necessary. Particularly if the system experiences small leaks at the corp valves (taps into mains).
If you hear a leak, listen at the adjacent service lines, hydrants, and valves. If the sound is louder, then you are closer. If you cannot tell which one is louder with your ears, then study the two-digit display: