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I have just dive with my new OSTC 2N. I had previously a STINGER SUUNTO and a GALLILEO UWATEC. On both of them I can use the computer in a more conservative mode than the normal one.
So these computers take my age (52) and my weight (102Kg) into account by amplifiyng the time during dive stops...

How to do that with my OSTC 2N?

Hi,

You'll have to play with Gradient Factors. The algo is ZHL16-GF (OC or CC).
Basically, there are two numbers to play with: GF-Low and GF-High. It's often written GFxx-yy with xx being the Low value and yy the High value.

GF100-100 will give you a pure Bühlman decompression curve.
The lower the High value is, the longer the last deco stops will be.
The lower the Low value is, the deepest the first deco stop will be.
This is to go fast, you can find many papers on the theory behind this (on the Shearwater site for example).

GF are good to play with when doing O2 deco stops, it does not have a lot of sense using them with air only.

If you want to dive nitrox, you can use 85-85 as it will give you more security than a pure Bühlman deco curve while not extending stops too much.

You could play with a simulator (MV Plan for example) to see how those GF act.

Some articles on gradient factors:
http://www.dive-tech.co.uk/resources/mvalues.pdf
http://www.dive-tech.co.uk/resources/deepstops.pdf

Beside the GF please also have a look to the various CF settings where you can define several additional tresholds and margins.

HTH,
Jan

i agree with Solodiver
If you dive with air or nitrox only, check CF11 and CF12 (default 110/90, 120/80 by exemple if you want more security)

Thanks for these info.

I have find in a book (Nitrox Trimix) explanation about GF Low and GF High. I have modify the CF 33 (GF High) with 80 instead of 90. It's still a trial and error process.
After some dives I will test CF 11 and CF12 with 120/80 .

Tx;)

MAES Alain

OSTC 2N 2537

For french speakers, there are nice explanation on decompression here: http://www.plongeesout.com/articles%20p ... ession.htm

Have fun.

François Peeters