Every service and repair contractor sooner or later needs to locate a leak. The technology available ranges from putting one's ear to the ground to computerized correlation.
When fluids like water escape from pressurized piping, they emit an "acoustic signature." Such sounds are normally composed of multiple frequencies that combine to form the signature sound. These different sounds are normally in the range of 100 to 800 Hz (cycles per second). Leaks at higher pressures produce higher frequency sounds; leaks at lower pressures produce lower frequency sounds. Both the material and the mass of the pipe carrying the water can also affect the frequency. Some noises even lower in frequency can be produced by the turbulence created in the loose fill adjacent to the leak.
Today's contractors have sophisticated leak-locating technology available to them that can detect leaks
by identifying their signature sounds. A sensitive transducer (microphone) can receive these sounds and
send them to a high-gain, low-noise amplifier in the instrument. The leak detector visually displays the
sound amplitude, then magnifies and transmits the sound to headphones worn by the technician.
Should You Buy One?If your firm performs slab leak repair procedures, you are presented with a couple of options. You can retain the services of a professional company that provides leak detection services and then rely on their skill and accuracy, or you can acquire your own leak-detection equipment. There are both advantages and disadvantages to hiring specialized subcontractors. Accurate leak detection and pinpoint location take significant skill and experience. Possessing the equipment is no more of a guarantee of successful diagnostics than possession of a scalpel makes a person a surgeon.
Professional leak detection companies have highly skilled technicians. One well-known leak detection firm puts its new service technicians through six weeks of full-time training before they are allowed to work in the field unsupervised. How many service and repair contractors can give that type of training to their techs?
With professional detection companies it's usually a find-and-forget process. Your service technician can be assured that where he is told to excavate is where he will find and expose the leaking pipe. But there are possible drawbacks to using an outside company. Some companies have poor accuracy reputations. Also, the price of three calls to an outside leak detection company can pay for an inexpensive leak detector.
Many contractors who own the equipment report that they use it as a marketing tool, letting clients know
that they are equipped to handle the procedure in-house from start to finish. Also, if the original leak
location was inaccurate, you are in a position to relocate it at minimal cost in a low-profile fashion.
Leak-locating technology will never be a substitute for mechanical aptitude and experience, but it sure
goes a long way to ensure success.
The ProcessThe service technician begins by interviewing the client and noting the history behind the symptoms, if any. Sometimes there are obvious symptoms, like water gushing up through the floor. Other times something as innocuous as a cat that habitually curls up in the middle of an otherwise cold, hard floor can be the tip-off to a leak. But most of the time sound trouble-shooting skills are employed.
First the service technician should perform a water meter reading to make sure there is a water demand. Then a thorough inspection is made of the inside of the premises. Usually a leaking fixture is found, but if not, then the interior water system can be isolated from the outside water main and irrigation. If the leak is found outside, oftentimes the condition of the pipe will determine your course of action. Depending on the material from which the leaking pipe was made, the technician can give the client the option of material replacement or repair.
If the leak is inside and concealed - as in under a slab concrete floor - then leak detection is warranted. The technician begins by "pre-locating" the leak. This is done by taking the acoustic microphone and contacting hard piping points throughout the water distribution system. Typically this means emergency water shutoffs underneath fixtures, or the inlet/exit piping to a water heater. With some leak-detection instruments, peak sounds can be recorded on the display. With analog units, the tech makes a mental note of the highest value sound. Once this is acquired, the technician then goes back and uses a conductive pipe locator to trace out where the concealed pipe runs. Then over this line trace, the service technician again finds the highest peak sound that is over the pipe.
Once this sound is located with spectrum-analyzing leak detectors, the technician can then record the highest peak intensity within the sound spectrum range. After the frequency is observed with the strongest signal, the technician can filter out any other anomalous sounds and just target the sound within the selected frequency.
Most contractors are familiar with basic leak-detection instruments. They have a simple analog meter dial and controls, and are comparatively inexpensive. The only advantage to this type is its low price. This isn't necessarily a feature to be taken lightly. If you're losing leak detection income because you don't have equipment, all the switches and knobs on a feature-packed leak detection instrument won't do you any good if it is sitting on the manufacturer's shelf instead of yours.
If you have the budget, what will the high-end instruments do for you? Without proper training, they will just eat up your budget and confuse your tech if he tries to use them. But with proper training, they provide more clues than non-spectrum analyzing models. Will you need that? Oftentimes no. But many successful contracting business owners purchase the top of the line in equipment, even if it has features that aren't needed at the moment. That way, if you do need them later on, you won't have to upgrade.
There is one point to consider when deciding whether to purchase high- or low-end equipment that is almost always overlooked by contractors, and that's client perception. I once went into a dentist's office where the equipment was 40 years old. I wanted to get out as quickly as possible, despite the possibility that the dentist was quite competent and experienced.
High-tech equipment, when observed by clients, can make the difference between client satisfaction and a price complaint. I once assisted on a call with a tech who was using a simplistic pipe tracer. The homeowner watched and heard the obvious audio tone when the tracer antenna was over the pipe. Even though he had previously agreed to the price in writing, he declined to pay the company because he said it looked "too easy."
If you advertise, make sure you include the feature "Electronic Leak Detection." Clients will call you solely because of that, even if the equipment isn't necessary for you to diagnose the cause of their particular problem. It's a real draw. If others are advertising electronic leak detection, if you acquire a spectrum-analyzing model you can truthfully advertise "Spectrum-Analyzing Leak Detection."
When doing telephone consultations, you can advise your client that you use only spectrum-analyzing instruments. These things immediately set you above and apart from other companies in the eyes of prospective clients - even if you don't need the features on a given repair procedure.