Corroding Aircraft
	Non Destructive Evaluation Tools
		Eddy Current Tester
has the acronym CAN DETECT
and refers to three projects that assist with light aircraft maintenance.

Flying a light aircraft can be cheaper than many arcade video games,
even though maintenance is about a third of the cost.
Non destructive evaluation technologies
aim to minimize the amount of disassembly,
reducing labor as well as wear-and-tear from inspections.

Corrosion inspection is especially difficult
because water accumulates in the low corners that are hard to get to
such as between sheet metal layers that are riveted together.

A so-called eddy current probe applies a magnetic field from the outside,
measures the response from each layer of metal
and estimates how much metal has corroded away.

One of our three projects is designing a probe
using new magnetoresistive sensors
for high performance at a low price.

Eddy current measurements are usually made at high frequencies,
far above the range humans can hear.
Thick layers of aluminum need a lower frequency to penetrate the material,
so we can use a generic sound card if it is capable of stereo full duplex.

The second of our three projects is currently writing a subroutine library
to replace an expensive audio network analyzer with the Open Sound System.

The Federal Aviation Administration has a database listing all qualified
aviation maintenance technicians with over a third of a million people.
They use workshops at airports all over the country,
in industrial parks older than the internet and maybe the personal computer.
Electrical power is unreliable and internet access might be unavailable.
This is a difficult environment for recent operating systems
that assume 'net connectivity, take a long time to boot
and don't journal their files.

The last of our three projects aims to put all the software we need
on a CDROM so it can easily run on any computer with compatible hardware.

For example,
the $200 unit from the New Internet Computer company
is already designed to run from a CD
and includes a sound chipset that meets our needs.
In conjunction with the Embedded Linux Journal competition,
a unit was donated to this project and development is continuing.

Thank you for your interest,
our project website is "CAN DETECT" as one word on SourceForge.

Any questions ?