A Note About Removable Memory - Valeport MIDAS WLR Hardware Manual

A NOTE ABOUT REMOVABLE MEMORY

We are sometimes asked whether we offer these devices with removable memory. The
answer is no we don't, but there are sound reasons for this. It is natural to think that
since removable memory cards are now the norm in consumer electronics, they must
be "state of the art" and therefore desirable in all applications, but this is not necessarily
the case.
An essential feature of an underwater instrument is that it is water-tight; this is
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achieved by using various seals on the mechanical parts of the device. Every
time that one of these seals is broken and remade, it introduces a small risk that
the seal is not correctly made, and the instrument could leak. The fewer times
that the device has to be opened, the better – you certainly wouldn't want to do it
after every profile to get the memory card out.
All memory cards are susceptible to ESD shock (static electricity) while being
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handled. We take the view that the value of your data means it shouldn't be
exposed to the possibility of this risk, which could result in loss of all data on the
card.
Memory cards are not particularly efficient at storing data – they will only accept
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minimum sized lumps of data at a time. This may be perfect for a camera where
you instantly generate a few Mbytes, not so for an application where you only
want to store a few bytes of data at a time.
From a practical point of view, the time taken to connect a cable and extract the
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data to PC is actually typically much less than the time to open the device,
remove the memory, replace the memory, and close the device up again.
The implementation of removable memory is not technically difficult, but we
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believe that the disadvantages currently outweigh any possible advantages in
this product and its applications. However, should circumstances change it will
of course be considered for future product enhancements.
M WLR Hardware Manual
IDAS
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