*****SPAM***** Re: Cylinder pressure interpolation and end pressure display for CCR

[Willem Ferguson]

On 09/11/2014 15:10, Rodrigo Severo wrote:
> On Sun, Nov 9, 2014 at 5:49 AM, Willem Ferguson
> <willemferguson at zoology.up.ac.za> wrote:
>> As far as the present implementation is concerned, I suspect it would be fairly easy (not simple) to to changes. We just need to agree on the principle of interpolation for the diluent.
> I was initially proposing a method that would use the regular OC depth
> dependent interpolation method with one modification: only the samples
> that represent an increase in depth to be considered, i.e., when
> ascending or maintaining depth, we would consider diluent consumption
> as zero.
>
> This method creates the problem of separating what actually is a depth
> increase and what is simply noise in depth reporting. Two methods
> where suggested to solve this issue:
>
> * a threshold (3 feet? something changeable by the user on
> preferences?) that would define the minimum depth change that we would
> actually consider a depth increase
> * a 1 minute time average depth (suggested by Dirk).
>
> I like Dirk`s idea but I believe any one of them would work.
>
> Regarding the graph you posted Willem, I believe that during ascends
> and fixed depths periods, the diluent graph should be a perfect
> horizontal line (no consumption as I mentioned above).
>
>
> Regards,
>
> Rodrigo
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Thanks, Rodrigo,
These are real readings taken with accurate pressure sensors on both the 
oxygen and diluent cylinders. Is the real-life situation perhaps a bit 
different from the expected theoretical situation? You guys have the 
experience. Certainly one cannot ignore the real measurements?
Kind regards,
willem