BACKGROUND: Engineers are using the tether-controlled Sahara sensor inside water mains to pinpoint even the smallest leaks - without disrupting pipeline service. Consumers can't see the technology but the nonetheless reap the benefits: the sensors ensure that water keeps flowing through pipes reliably and safely.
HOW IT WORKS: The system is inserted into a live transmission main through any tap two inches or more in diameter. It is safe for all drinking water systems. The probe is carried along the pipe by the flow of water, and the system locates leaks as small as one-quarter of a gallon per hour. It does this, in real time, through the identification of distinctive acoustic signals generated by leaks in the pipe walls, the joints, or steel welds. Once a leak has been detected, the sensor head can be stopped at the precise position of the leak. Its location within the main can be identified from the surface and accurately marked for subsequent excavation and repair. As a result, operators can also use Sahara to accurately map the course of a pipeline.
BENEFITS: Depending on the pipe configuration, lengths of up to 6000 feet can be surveyed with a single insertion, and inspections can be conducted in mains with a diameter of at least 12 inches. The ability to identify individual leaks has many benefits, such as helping water transmission pipeline operators pinpoint the exact location of the leaks causing a pipeline to fail a pressure test. Based on this information, it is easier to establish priorities for repair and replacement of parts. More generally, being able to establish the structural integrity of a given water transmission main makes it easier to more accurately value pipeline assets, and comply with legal requirements.
SENSING ABILITY: A sensor is a type of transducer: an electronic device that converts energy from one form to another. For instance, microphones convert sound waves into electrical signals, while speakers receive the electrical signals and convert them back into sound waves. There are many different kinds of sensors, but most are electrical or electronic. Microelectro-mechanical systems (MEMs) integrate electronic and moving parts onto a microscopic silicon chip, making them ideal for new sensor technology. The term MEMS was coined in the 1980s. A MEMS device is usually only a few micrometers wide; for comparison, a human hair is 50 micrometers wide. Among other everyday applications, MEMS-based sensors are used in cars to detect the sudden motion of a collision and trigger release of the airbag. They are also found in ink-jet printers, blood pressure monitors, and projection display systems.
The American Waterworks Association contributed to the information contained in the TV portion of this report.