PresentationPDF Available

Background Information on the update 03 / 2021: Decompression-Calculations for Trimix Dives with PC-Software; Gradient Factors: do they repair defective algorithms or do they repair defective implementations?

Authors:

Abstract

Background Information on the "update 03 / 2021" to the 2011 paper from smc-de.com: Decompression-Calculations for Trimix Dives with PC-Software; Gradient Factors: do they repair defective algorithms or do they repair defective implementations?
1
Background Information on the
update 03 / 2021:
Decompression-Calculations for
Trimix Dives with PC-Software;
Gradient Factors: do they repair
defective algorithms or do they
repair defective implementations?
2
Decompression-Calculations for Trimix Dives
with PC-Software;
Gradient Factors:
do they repair defective algorithms or
do they
repair defective implementations?
The overall # of profiles as a data base for this communication [1],
resp. [1a]:
4 software products (2 different versions of DIVE, COTS 3, COTS 4)
one of the COTS products being GAP, Version 3
6 bottom-depths: 30, 40, 50, 60, 70, 80 m
5 bottom-times: 20, 30, 40, 50, 60 min
16 Helium fractions per mix: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55,
60, 65, 70, 75, 80 %
i.e.: 6 * 5 * 16 = 480 box profiles per software product
that is: 480 * 4 = 1.920 profiles overall in the data base
3
Decompression-Calculations for Trimix Dives
with PC-Software;
Gradient Factors:
do they repair defective algorithms or
do they
repair defective implementations?
There is a wealth of data in this report, Ref. [1]
and the topical conference paper: „update per 03 / 2021“ [1a]
and as well a huge data base, not fully exploited:
30 graphs like Chart (2), pls. cf. next slide
underlining the basic messages:
• Δ TTS > 0, decreases slowly @ fHe 30 40 %
• Δ TTS vanishes @ fHe around 30 to 40 % for nearly all evaluated
profiles
• Δ TTS < 0 , increases with inceasing decompression obligation
AND Helium fraction fHe
4
Decompression-Calculations for Trimix Dives with PC-Software;
Gradient Factors: do they repair defective algorithms or do they
repair defective implementations?
5
base line: numerical solution
: Σ (tD,1 + tD,2 + tD,3) / 3
Decompression-Calculations for Trimix Dives with PC-Software;
Gradient Factors: do they repair defective algorithms or do they
repair defective implementations?
6
Decompression-Calculations for Trimix Dives
with PC-Software;
Gradient Factors:
do they repair defective algorithms or
do they
repair defective implementations?
There is as well a wealth of data in the published Chart (2) in [1], [1a}:
for one box profile ( = 1 combination of one bottom-depth
with one bottom- time) it condenses 16 * 4 datasets
1 data set = green line, the bottom line of method A)
defined as: TTS = 0 for the numerical method
3 data sets = black line
the black line with the consists of the arithmetic mean of the
calculated TTS, according to: ∑ = TTSi / 3 with i = 1 3
Let‘s have a closer look at Chart (2), pls. cf. next slide:
7
Instead of 16 data sets, there is only each 2nd. set depicted;
double arrow: Delta TTS, increasing with increasing Helium fraction
error margins: only through the GAP software,
since: Δ TTS = 0 between one COTS product & DIVE with method B)
8
Decompression-Calculations for Trimix Dives
with PC-Software;
Gradient Factors:
do they repair defective algorithms or
do they
repair defective implementations?
The 4 desktop deco software products under comparison:
DIVE Version 2_900 with method B), obsolete since 2013
due to not running under Windows 7 or higher
DIVE Versions 3, now 3_09 with methods A) and B) , pls. cf. ref. [2], [3]
COTS (commercially off-the-shelf) #3
COTS (commercially off-the-shelf) #4:
9
Decompression-Calculations for Trimix Dives
with PC-Software;
Gradient Factors:
do they repair defective algorithms or
do they
repair defective implementations?
References:
[1] Salm, Albi (2012) Decompression-Calculations for Trimix Dives with PC-
Software; Gradient Factors: do they repair defective algorithms or do they
repair defective implementations?
DOI: 10.13140/RG.2.2.35405.87527
[1a] update per 03 / 2021
(PDF) Update per 03 / 2021 on: Decompression-Calculations for Trimix Dives with PC- Software; Gradient
Factors: do they repair defective algorithms or do they repair defective implementations? (researchgate.net)
[2] Salm, Albi (2021) Synopsis and Fact Sheet
(PDF) Synopsis & Fact Sheet: PoC for DIVE (Proof of Concept for a free-/shareware decompression suite)
(researchgate.net)
[3] www.SMC-de.com (1991): DIVE, a desktop decompression suite for
Win7, german version:
https://www.divetable.info/DIVE_V3/index.htm
ResearchGate has not been able to resolve any citations for this publication.
Preprint
Full-text available
If there is more than one inertgas in the breathing mixture, the calculation of the decompression-time t d has to be done numerically. We analyzed 480 square dive-profiles in the TEC/REC range with one freeware, two commercially available software-packages and via numerical methods (depth range: 30-80 m, bottom times: 20-60 min, helium percentage: 5-80 %, only normoxic mixes i.e.: no travel-or enriched deco gases, only ZH-L model, no adaptions with gradient factors). There are significant differences in the calculation of the decompression-times t d with trimix gases, obviously dependent on the helium percentage. In the present analysis, these differences do not come from variations in the decompression algorithms.
Synopsis and Fact Sheet
  • Albi Salm
Salm, Albi (2021) Synopsis and Fact Sheet