Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Optical innovator uses soda-straw-like tubes to solve widespread sensing problems

12.01.2005


Car battery failing? Hazardous material leaching? Oil level dropping?



There you are, tapping your fingers on the cold steering wheel as your windows cloud over from your breath. How could you have known your car battery was that low? Sending weak beams of light through inexpensive glass tubes that resemble soda straws, Sandia National Laboratories researcher Jonathan Weiss - dubbed by some the "light wizard" - can inexpensively solve problems ranging from the migration of waste through a landfill to detecting when an automobile battery soon will be too weak to start a car.

Similar sensors also could tell oil field operators when to stop pumping oil from their tanks before the pumps pick up water that accompanies oil from the ground.


The oil/water interface sensor is the subject of a pending Sandia patent application and a research agreement with Custom Electronics, an electronics company in upstate New York. The company is partnering with Sandia, a National Nuclear Security Administration (NNSA) lab, to develop a prototype device from the current bench-top demonstration.

The car battery solution awaits a visionary entrepreneur to put this cheap, safe, patented solution in the hands of the public. And in an invited talk at a recent American Soil Society meeting on Nov. 3 in Seattle, Weiss presented his patented device for detecting hazardous waste movement.

Avoiding the unexpectedly dead battery problem A turkey-baster-like device inserted into a popped-open port has been the traditional way for a driver to test the amount of acid in a car battery (and possibly splash sulfuric acid on his or her fingertips). Weiss’s simple invention requires no direct human intervention under the hood.

His procedure: factory-inject sulfuric acid or even, possibly, sugared water into a clear glass tube smaller than a soda straw and immerse the tube in the battery’s acid. Glass is inert in acid and should have ample longevity, he says.

Next, send light through the tube and measure the amount that returns. (The light is generated by hardy, inexpensive diodes [LEDs] already mass-produced for traffic signals, house night lights, bike tail lights, and instrument control panels.)

The amount of light that stays in the tube depends on the refractive index of the surrounding solution. If the refractive indices are identical, light would just as soon escape from the sides of the tube as stay within it. That is the case when the tube is filled with sulfuric acid at maximum charge. The refractive index is at first the same as that of the battery acid surrounding it (1.38). But over time, the battery’s acid weakens and becomes more like water (1.33). Its lessening refractive index attracts less light from the tube. The exchange rate, in a manner of speaking, is worsening, and light remaining in the tube (as reflected by a tiny piece of metal placed at the tube’s far end) increases.

A simple solid-state light detector - a photodiode - at the tube’s near end registers more light, therefore, as the battery deteriorates. The detector could easily be wired to activate a dashboard alarm light similar to ones that notify a driver that a seat belt is unclasped.

Sugar water inserted in glass tubing also works well, Weiss says, because the refractive index of water can be adjusted upward by dissolving sugar in it. "Quite a substantial change can be produced, far exceeding that needed for this application," he says.

While the glass of the tubing does have an effect on light leakage, says Weiss, "the liquid core and liquid cladding are dominant." The tube is a millimeter in diameter, two to three inches long, and inexpensive: 200 tubes set Weiss back $10 for his experiments. Mass production would drive costs down even lower.

Measuring battery deterioration will become increasingly important as more hybrid electric/gas vehicles, with their high reliance on batteries, take to the highways, he says. Another possible use for the device is for cheap, continual monitoring of battery banks maintained by local phone companies. The batteries are used for back-up power to keep home phones working when wall-current electricity fails due to an outage.

Using light to find the level of oil and water in a tank Imagine you’re in the oil business and you’ve pumped oil and water (just the way it increasingly comes out of the ground) into a holding tank. You want to retrieve only the oil floating atop the water so you can transport the least possible weight from the oil field to a refinery. How do you know - accurately, safely, and simply - when to stop pumping?

This widespread problem is often solved currently by the most primitive means: An employee opens a hatch and drops a stick into the liquid, possibly inhaling its fumes as pumping is in progress.

With trivial hook-ups and a bit of engineering logic, Weiss shows - at least in laboratory demonstrations - that the answer to this problem can be quickly determined.

Weiss’s recipe: Take two five-foot-long optical fibers made of plastic. Mount them vertically in a tank that holds water with oil on top. Send light down one fiber, and then detect light carried back up by the second fiber. The strength of the detector’s signal depends on the height of the oil/water interface. If the tank is all water, the signal is very strong, and the pumping machine is instructed to stop pumping fluid; there is no oil left. "The device is immune to electromagnetic interference and will not create sparks in a potentially explosive environment," says Weiss.

The possibility of sludge building up on the device, muting the light, as the large tanks are filled and depleted is a potential reliability problem that might be overcome by "potting" the fibers in a clear plastic that repels hydrocarbons, says Weiss.

The transfer of this technology to a private company is the maiden effort of Sandia’s new Mission Centric Venturing program, intended to expedite interactions with industry. The program offers Sandia researchers the alternative of marketing their ideas commercially while remaining at Sandia.

Detection device for landfill When people are interested in the behavior of a landfill that holds chemicals that may undesirably leach into groundwater, the problem naturally comes up: How can an observer tell what the chemicals in a landfill are doing?

For leaching to occur, liquid must be present.

Weiss’s solution: Arrange two fiber optic cables like snakes, one above the other, in the landfill. Shine a light through the fibers. Because the temperatures of the fibers change the amount of light scattered by them, the emissions can be used to indicate the temperature at any point along the fiber. That temperature is determined in part by how much water is in the surrounding soil. Thus, fluid flowing down through the landfill would produce a clear signal from the wetted, cooled fiber.

Weiss’s innovative fiber optic sensors have received 12 patents in the last ten years - five of them with Sandia and the others with the U.S. Department of Energy.

Neal Singer | EurekAlert!
Further information:
http://www.sandia.gov

More articles from Power and Electrical Engineering:

nachricht Multiregional brain on a chip
16.01.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht Researchers develop environmentally friendly soy air filter
16.01.2017 | Washington State University

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>