Too much deco

[Bech]

Hi,

I have more than 30 Tx dives with the same configuration to 50 meters but ...

For the second time I had a similar problem while using my OSTC has a back up of my VR3 : at the end of the dive the OSTC gives me at least 25 minutes extra than my VR3 or the one of my friend. Dives to 50 meters with trimix diluent 15/30 and 20/30.

VR3: conservatism +20%
OSTC : CC GF 20/80

Does someone have any idea?

Thanks

Raph

[heinrichsweikamp]

Hello Raph,

Which SetPoint did you choose and (more important) which firmware version as installed on the OSTC?

regards,
Matthias

[Bech]

Hi,

I always use SP 1.20 as fixed (no low set point) and firmware version was 1.38 the first time and 1.40 last weekend.

Raph

[Anonymous User]

I had one vr3 give me 60 minute more deco than my backup Vr3, both VPM and same conservatism... so comparing Vr3 with OSTc is of little benefit.

[Bech]

ok, maybee but what seems strange is the fact that sometimes the OSTC goes mad on deco, because each time my buddy who was on VR3 had nearly the same deco.

Most of the time the decos between OSTC and VR3 are similair except for the pyle stops.

Raph

[heinrichsweikamp]

Hello,

We've done a lot of dives with the new 1.40 until today and we did not see unexpected, excessive ( >99" ) deco anymore (A bug in the older version).
Some minutes differences (remember that the OSTC used Bühlman and the Vr3 VPM!) are normal, especially on longer and deeper dives.

OSTC does not make Pyle stops, in the GF modes the deco is calculated based on Gradient Factors. This is very different from Pyle stops.

regards,
Matthias

[Bech]

Our VR3 are not the VPM version but the normal buhlman. Due to the fact that it mainly happend on a unregular basis I am pretty there is a bug or a security factor, because I think it happens if while ascending I make a small descent for a few minutes (between 5 or 10 meters).

[heinrichsweikamp]

Do you have such a dive with the 1.40 and can post the .bin file (Can be exported with the Divinglog Downloaded ("Advances Settings"))?

regards,
Matthias

[Bech]

I try it ...

Is it ok?

[heinrichsweikamp]

Hello,

Sorry for the delay. I checked the dive and there is not the steep increase in deco that occurred in some older versions (bug). So if you not noticed anything unusual during the dive on the OSTC screen I'd say that the deco model in the OSTC just calculated more deco then the Vr3 did. It may be related to your Pyle stops which will add extra saturation with the Bühlmann model, of course.

regards,
Matthias

[Bech]

ok, last weekend I reduced the low GF on the OSTC and did not get the problem back (only one dive with this setting at the moment).

Thanks for you help.

Raph

[Bech]

Same problem last weekend.

Saturday : 30m 70min without problem
Sunday : 71m 80min without problem
Monday : 40m during 7min after 30min at 12m, It gave me 44min deco time while the VR3 (conservatisme +20) gives nothing, except the Pyle stops!!!

OSTC version 1.40, SP 1.2, GF 30/80

Raph