OSTC3 GF_high smaller than 70?

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cyril
Posts: 5
Joined: Saturday 13. July 2013, 20:23

OSTC3 GF_high smaller than 70?

Post by cyril »

Hi,

on my OSTC3 I'd like to have a more conservative GF_high. But it seams not possible to set values between 70 and 110. Is there a way to get smaller values?

Regards,
cyril
heinrichsweikamp
Posts: 4446
Joined: Sunday 13. May 2007, 18:07

Re: OSTC3 GF_high smaller than 70?

Post by heinrichsweikamp »

No, 70 is the most conservative setting.

Regards,
Matthias
cyril
Posts: 5
Joined: Saturday 13. July 2013, 20:23

Re: OSTC3 GF_high smaller than 70?

Post by cyril »

Hi Matthias,

is this a permanent problem or will this change in future firmware updates?

Regards,
cyril
wrobell
Posts: 105
Joined: Wednesday 28. January 2009, 16:28

Re: OSTC3 GF_high smaller than 70?

Post by wrobell »

hey Cyril,

why do you need less than 70% gf high?
cyril
Posts: 5
Joined: Saturday 13. July 2013, 20:23

Re: OSTC3 GF_high smaller than 70?

Post by cyril »

Hi,

because my instructor said so.
Have a look at: read.php?2,12060

Bye,
cyril
Olaf70
Posts: 11
Joined: Sunday 30. October 2011, 19:57

Re: OSTC3 GF_high smaller than 70?

Post by Olaf70 »

Just extend your latest stop by your own calculations. You do plan your dive don't you.
adrian-bluescuba
Posts: 14
Joined: Wednesday 15. August 2012, 20:27

Re: OSTC3 GF_high smaller than 70?

Post by adrian-bluescuba »

This is not a problem. Its is conservative enough.
www.bluescuba.net
kscksc
Posts: 5
Joined: Thursday 20. October 2011, 14:22

Re: OSTC3 GF_high smaller than 70?

Post by kscksc »

@cyril:
Yes, there are reasons to decrease the GFhigh lower than 70%. Some peples need very, very low GF's ..

I usually use 25/60 on deep trimix-dives. The dives are only some minutes longer, but very save .. sometimes i have to do more deep dives a day.

@Olaf70: The GFhigh does not only affect the latest stop.
The GF's for the deeps between the GFLow(at bottom) and GFHigh(at surface) are linear interpolated depending on the depth. Because on that, all "flat-Stops" are affected by the GFHigh.

@forum:
I use the OSTC as Backup. Why should i use any computer for backup, when i must under water "recalulate" the calculation of my backup-computer by brain ????
In that case i use a table for Backup and a very cheep sport-diving computer in gauge-mode ( i did exact that for many years and decides to use a backup-computer).

I think, it is a dangerous possibility of the OSTC3, that its possibe to set GF values greather than 90 % :
100% is pure bühlmann and there ist no question, that with pure bühlman the normal diver has an significant chance to get an DCI. For that reason, the GF's where implemented in the bühlmann-algorythm.

The OSTC2 was an experimental platform for "specialists" : there we have many options to change. I think, OSTC3 is for standard consumer market:

In the consumer marked the OSTC3 alowes to dive "dangerous" GF's i.e. 110, but it's not possible to dive very safe parameters - thats the thing i don't understand.


regards
Koni
Anonymous User

Re: OSTC3 GF_high smaller than 70?

Post by Anonymous User »

There are many using GF high >100 or >110 without problems...

Jo
heinrichsweikamp
Posts: 4446
Joined: Sunday 13. May 2007, 18:07

Re: OSTC3 GF_high smaller than 70?

Post by heinrichsweikamp »

We though 70% is conservative enough but it's an easy fix to have 60% as the lowest setting for the gf high...

Regards,
Matthias
heinrichsweikamp
Posts: 4446
Joined: Sunday 13. May 2007, 18:07

Re: OSTC3 GF_high smaller than 70?

Post by heinrichsweikamp »

Here you go. GF_high can be between 60 and 110, aGF_high between 70 and 120.

Cheers,
Matthias

P.S.: Just in case: Do not use a GF>85% for diving. No matter if you have heard that people "survive" with GF_high=100% or 110%. "Surviving" a dive is only one goal of a decompression schedule...
cyril
Posts: 5
Joined: Saturday 13. July 2013, 20:23

Re: OSTC3 GF_high smaller than 70?

Post by cyril »

I've tried to approximate OSTC3 deco calculations with V-Planner.
Given a 15min dive at 35m with air you get comparable results with GF 15/70. The OSTC result then is somewhere in between V-Planner with conservatism 2 and 3 (out of a total range of 0...5). This is a good medium of conservatism and not the highest rate. Therefore I think it's pretty good that we now have the possibility of a lower GF_high.

Thanks a lot for the update!

Regards,
cyril
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