Dive planner VPM-B problems

[Willem Ferguson]

On 17/10/2017 09:53, Stefan Fuchs wrote:
>
> Hello Willem,
>
> Am 17.10.2017 um 09:42 schrieb Willem Ferguson:
>> On 16/10/2017 21:56, Stefan Fuchs wrote:
>>>
>>> BTW: You could be one of the best candidates for testing my latest 
>>> changes around cylinder handling in the planner. It would be great 
>>> to hear from your side if this improves or breaks s.th. for you. 
>>> Robert merged the changes already but the PR was this one:
>>> https://github.com/Subsurface-divelog/subsurface/pull/663
>>>
>>> Best regards
>>> Stefan
>>>
>>> -
Stefan,

I have been trying out a lot of things around dive planning today this 
afternoon to test your patches within my dive context. I could not find 
any problem. Attached one of the dives I worked with. I loved it when 
changing the gas of the first segment of the dive, the cylinder table 
changed to put the gas first used at the top. I added segments at the 
bottom of the dive planner points table and these were placed at the 
start of the profile if the runtime was set appropriately. I really 
messed around, deleting cylinders, changing cylinders and adding 
cylinders and everything remained coherent and stable. I also see that 
all the cylinders used in the dive planner points table are marked as 
non-removable from the dive. Ok, Good.

About minimum pressures, you can see that the minimum pressure is given 
for the final bottom gas. As planned, there are 34 bars of bottom gas 
required to from the start of ascent complete the dive. If I double the 
deco SAC (SAC factor = 2) I would need 41 bars of back gas for the 
ascent. If I took one minute for problem solving I would need 
30(litres/min=2*deco SAC)*9(atm) = 360 litres of air = 11 bars of D12 
cylinders. That is 45 bars in total. But the problem solving would have 
been at the bottom depth (80m) before ascent, therefore the problem 
solving need is possibly better defined in terms of the bottom SAC, not 
the deco SAC (i.e. 15 bars and not 11 bars). But, I am very slowly 
getting to understand the argument.

Kind regards,
willem



-- 
This message and attachments are subject to a disclaimer.
Please refer to 
http://upnet.up.ac.za/services/it/documentation/docs/004167.pdf for full 
details.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: plan2.jpg
Type: image/jpeg
Size: 100594 bytes
Desc: not available
URL: <http://lists.subsurface-divelog.org/pipermail/subsurface/attachments/20171017/8c9815dc/attachment-0001.jpg>