The statistics are alarming: Up to 40 percent of fresh water flowing through supply pipes today never reaches the end consumer, but seeps out unused through leaks and into the ground. This is because many of the pipes are now over a hundred years old and correspondingly fissured. So far, there has been no cost-efficient way of detecting these leaks. Conventional high-end flow sensors, which cost 1000 to 2000 euros, are too expensive to be used throughout entire networks.
On behalf of Pisa’s water supply company Acque S.p.A., researchers at the Fraunhofer Institute for Silicon Technology ISIT in Itzehoe and their Italian colleagues at Sensordynamics have developed a cost-efficient alternative: silicon-based sensors. These only cost around five percent of the average price of their high-end counterparts. The new probes function according to the same principle as mass air flow sensors, which have been used for some time to measure the air intake in car engines. “Now we are able to use these sensors in liquids for the first time,” says ISIT project manager Dr. Peter Lange.
At the heart of the sensor are two heating wires, which are mounted one behind the other on a thin membrane. An electric current flowing through the wires heats them to a constant temperature. When cold water flows past them, the front wire gives off more heat into the water than the rear one, which is in its slipstream. Accordingly, a higher current has to flow through the front wire in order to keep the temperature constant. On the basis of this difference in electrical current, it is possible to determine the speed and volume of the water traveling through the pipes.
The special feature of this sensor is that it operates in pulse mode. The wires are not heated constantly, but only for about three seconds per minute, which means that they are cold most of the time. This helps to reduce lime deposits and air bubbles, which could otherwise distort the measurements. Another advantage of pulsed operation is that it saves energy, and the batteries last much longer. The first tests were successful: The sensors survived for three months under water without suffering any damage. For further tests, the researchers integrated 70 prototypes into Pisa’s water pipes just a few weeks ago. There, they must withstand the flow for several months at full operation, measuring how much water is traveling through the supply pipes and where it is lost. “The data can be retrieved by mobile phone or radio,” says Lange. If the tests are successful, it is perfectly conceivable that the sensors will be produced at a rate of 50,000 to 500,000 per year.
Press Office | alfa
Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide
Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering