Differences in VR3 run times

womble

I have 2 VR3's, one is version 3.03aC, the other (newer one) is 5.03aC. On a number of dives now I have found that the version 5 adds about another 5 minutes of deco. I've checked all the settings, both 'pooters are the same, I wear them on the same arm, both run the same setpoints (1.25), same gasses etc. The newer one is running the Bhulmann algorithm, not VBM.

I've also found if I change the setpoint on the version 5 from 1.25 to 1.35, the older VR3 still gets me out of the water quicker . .

Does anyone know why this is?

Oooops, should haved posted this in the computer forum . . DOH!!

womble

Anyone???

divetheworld

No idea, was watching hoping someone could explain it. I have a 3.03ac, would be nice to wear two identical to find out if there is a problem with one.

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Gobfish1

you could sell one , that will sort it

Deepthought_reloaded

The one nearer the wrist ends up being several centimeters deeper for the entire duration of the dive...

Seriously though it is likely to be a combination of issues
The software change is likely to be a major part, calculations may have been made more efficient to allow for new features e.g. tank pressure monitor.
If you look at the rate that compartments become saturated that may show a variation between the two algorithms

There may be minor differences in calibration, in battery voltage, the pressure/depth transducer may have been improved....

My old Physics teacher would have quoted something about the difference between Accuracy and Precision " a rifle with a bent sight is precise - it will miss the target every time (but by the same amount) a shotgun is accurate - it will hit the target but the pattern of pellets is different each time...."

Presumably there is no major discrepancies overall e.g. one says you dived to 50.7m and the other to 51.3 ....

Maybe worth contacting DeltaP - they'll know more about how the software has changed they may even be able to offer an upgrade...

womble

Cheers guys, will contact Delta P

dan@scuba-training.net

A man that has one watch knows what time it is.

A man with two watches is never sure...

decoweenie

A man with 3 watches can do voting logic...

If that fails, pull out the attached 4th "watch" (i.e. sun dial) to manually determine the correct time.

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johnv

The difference will almost certainly be down to the software version.


John

Drmike

Yes:
The deco algo in VR3s has changed over the years. I have 3 of different ages and they give different results (The oldest apears to be more conservative)

I use that one more as an expensive back up and bottom timer. If I used it for deco Id still be in Sra Keow now

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