an analogous machine (70's)
In the 70's there was an analog dive computer available:
Gehaeuse = housing, Druckmesser = pressure gauge (bourdon type),
- it was italian made
- it was called "SOS" (don't know why ...)
- simulated exactly ONE compartment, that is: one half-time
- normally, a dive to 45 m and 30 min. did usually show up no deco time
- which, at that time, was normal for us, because deco meant to us the same
- what a hyper-oxic seizure meant to Hans Hass 15 years before
- more or less: nothing
- now, times have changed ...
- have a look at the box (the tip of the pencil is just for size reference):
- and at the internals:
PVC Balg = plastic bag, Keramikfilter = sinter filter, N2 = nitrogen gas
the ambient pressure through diving forced the nitrogen gas in the little plastic bag
through the filter into the pressure gauge, thus moving the pointer.
The filter thus simulates the half-time of one compartment via it's resistance to the gas-flow.
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