NASA Helps Keep Boat Owners From Running Out of Gas
Boat owners now have a better idea of the amount and purity of their fuel thanks to a NASA-developed wireless sensor technology.

Originally developed at NASA's Langley Research Center in Hampton, Va., to retrofit aging aircraft with vehicle safety monitoring equipment, the technology is a spinoff for designing and using sensors without the shortcomings of many commonly used measurement systems.

NASA senior scientist Stan Woodard and Bryant Taylor, an ATK Space Division electronics technician, created a wireless fluid-level measurement system that eliminates the need for any electrical component or circuit to be in contact with combustible fuel or fuel vapors. The wireless fluid-level measurement technique is simple to use, install, and in use by commercial and recreational boaters.

NASA approved a partially exclusive license agreement for wireless sensor technologies between NASA and Caplan Taylor Enterprises LLC doing business as Tidewater Sensors. Located in Newport News, Va., Tidewater Sensors markets and sells the fuel sensor units internationally.

Wireless fluid-level measurement system for marine use developed by Tidewater Sensors, Newport News, Va.
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A wireless fluid-level measurement system for marine use from Tidewater Sensors, Newport News, Va. NASA approved a partially-exclusive license agreement for its wireless sensor technologies with the company. Outside of the fuel gauge, the system has no moving parts inside the boat's tank. Credit: NASA


Hampton, Va., police boat with sensor installed, inset: close-up of fuel gauge

This Hampton, Va., police boat has a NASA-developed wireless sensor technology. The wireless fluid-level measurement system is more accurate than conventional systems and eliminates the need for any electrical components to be in contact with combustible fuel. Inset: Close up of a boat's fuel gauge after a retrofit with the wireless sensor technology. Credit: NASA

Traditional marine fuel-gauge float systems can experience inaccurate readings due to movement; a boat's pitch and roll in open waters can create a "seesaw" effect on fuel gauges. But the wireless fluid-level measurement system has two stationary pieces of conducting material in the fuel connected to an inductor on the outside of the tank.

When the system activates the internal fuel sensors using a harmonic magnetic field, the external sensor becomes powered and responds with its own harmonic magnetic field. A frequency corresponds to the amount of fluid in the sensor's electric field and is accurate regardless of the amount of fuel movement in the tank or the boat's position. The signal is then wirelessly transmitted to an antenna and sent by cable to a standard fuel gauge.

A key and unique safety feature of the system is that it allows the sensors to be completely enclosed so that the fuel level can be measured without contact with any electrical components. This eliminates the potential for fires as a result of combustible fuel vapors being ignited by arcing from damaged or exposed electrical wires or panels. This design feature also allows the system too be used with fluids like acids or other harsh chemicals.

"That is its best embodiment as an improvement over current fuel systems," said Stan Woodard, "And it's very easy to retrofit into existing vehicle tanks."

Another important aspect of the wireless fuel-level sensor system and a major concern for boaters in a marine environment is that its design can be modified to detect water -- similar to a commercial version of the sensor. It can also be modified to detect other non-fuel liquid contaminants in the tank. And although this particular system is for a marine application, Woodard says it could easily be used for any type of vehicle: truck, train, boat, plane, or car.

"Although the fluid-level measurement system gets lots of attention, the fundamental technology could be used to design an unlimited number of sensors for a variety of measurements," added Woodard. "Just think about anything that you would want to measure. Don't be surprised when you see this technology commercially available in your home or cars."

For more information:
  › http://technologygateway.nasa.gov/
  › NASA Langley's Fluid Measurement Sensor
  › http://tidewatersensors.com/

Christopher P. Rink
NASA Langley Research Center