Regarding the saltwater submersion: I think your scenario is not correct.
The whole orange thing displayed on that page will be have to be in contact with saltwater. Otherwise the ultrasound pinger (the cylindrical aluminum thing) doesn't even start emitting pulses... (conductive liquid on sensor pads is how they normally detect that they have to turn on)
The "lifetime" of 30 years, or 17'000 operating hours is for how long it's certified to run in a non-crashing normally operated airplane.
The 30 days in saltwater probably means that no moisture will have crept in through the covers and seals: You can rinse the power-connector and Ethernet with deionized water, let it dry, connect to the computer and read it out.
{A assume that these devices are read out much more often in cases of non-fatal crashes where they weren't subject to the elements that much.}
The block diagram they show has an separate component for the nonvolatile memory, in a "Crash Survivable Housing". Also I assume that the company at least has some plan for accessing data given a complete disintegration of the memory module, probably by contacting single flash chips.
EDIT/ADDED:
http://edition.cnn.com/2014/04/23/world/asia/malaysia-370-bl... says: """A lot of our work is with undamaged recorders and it's very easy to download them, much as you would a USB memory stick,(...)""" and """One of the most challenging scenarios is when the board itself is damaged: "We could take each individual chip off the circuit board, read those out individually, and then with the help of the manufacturer, piece all that information together,"""
The whole orange thing displayed on that page will be have to be in contact with saltwater. Otherwise the ultrasound pinger (the cylindrical aluminum thing) doesn't even start emitting pulses... (conductive liquid on sensor pads is how they normally detect that they have to turn on)
The "lifetime" of 30 years, or 17'000 operating hours is for how long it's certified to run in a non-crashing normally operated airplane.
The 30 days in saltwater probably means that no moisture will have crept in through the covers and seals: You can rinse the power-connector and Ethernet with deionized water, let it dry, connect to the computer and read it out.
{A assume that these devices are read out much more often in cases of non-fatal crashes where they weren't subject to the elements that much.}
The block diagram they show has an separate component for the nonvolatile memory, in a "Crash Survivable Housing". Also I assume that the company at least has some plan for accessing data given a complete disintegration of the memory module, probably by contacting single flash chips.
EDIT/ADDED:
http://edition.cnn.com/2014/04/23/world/asia/malaysia-370-bl... says: """A lot of our work is with undamaged recorders and it's very easy to download them, much as you would a USB memory stick,(...)""" and """One of the most challenging scenarios is when the board itself is damaged: "We could take each individual chip off the circuit board, read those out individually, and then with the help of the manufacturer, piece all that information together,"""