forum.heinrichsweikamp.com

Hi, I think this has been discussed in German already but my translation skills are too rusty to understand it all.

I have been running simulations on my OSTC prior to it's first dive this weekend and I cannot get the TTS to match the deco obligation even though I take into consideration the 10m/min ascent rate. I always gain a minute or two on the TTS. I noticed this as I was trying to work backwards from the deco obligation to give me dive run times.

Having looked around the forum I came across a post with the attached file. It shows a couple of simulated dive profiles but running a ruler against the screen indicates that the dive end point doesn't match the text on the right of the graph. If you go by the x-axis only you are out of the water a minute or so before the text says you are.

I also noticed that when I ran a full 40min dive simulation on the OSTC my TTS was 3mins when I had only 1min of deco left.

Am I missing something really obvious?

Thanks Nick

(attachment borrowed(!) from a post by JeanDo on CF55...thanks)

The OSTC calculates with an ascent rate of 7m/min. This is one reason for some minutes. Another one might be, that the computer calculates seconds but only displays rounded figures - may result in another minute. What I can't see from here, if you have also changed some CF's that might influence calculation like CF55 (gas change time).

Hi,

It's 10m/min and one additional minute for the way between 3m and the surface. All is rounded up to the next full minute.

Regards,
Matthias

I was sure that I read 7m/min somewhere here in the last months...

7m/min is the default value to display vertical velocity (CF05)
and CF47 display color warning

Bühlmann algorithm use 10m/mn to calculate TTS and stops

Yep, maybe I mixed those values...