Missing Default tank on DC import

[Steve Butler]

On 11/23/2014 07:34 AM, Dirk Hohndel wrote:
> On Sat, Nov 22, 2014 at 11:30:33PM -0800, Steve Butler wrote:
>> Deleted last dive so I could import from DC.  It came in without the default
>> tank from my preferences (HP119).
>>
>> In addition, when I selected HP119, the cu ft is not 123 (the manufacturer
>> of my XL-119 tanks claims they have 123 cu ft at 3442 #).  I have verified
>> that all occurrences of HP119 in my dives have been modified to show 123.
>> Is there some other place I should change?
> What's the wet volume of that tank? It's possible that the manufacturer
> gives the gas volume based on the ideal gas law (i.e., wet volume
> multiplied with the pressure in bar). But air doesn't behave like an ideal
> gas at higher pressures. We try to calculate an approximation of the real
> behavior of air (look at surface_volume_multiplier() in dive.c) which
> gives a lower gas volume at higher pressures as you would assume by simply
> using the ideal gas laws.
>
> /D
>
The specs are:  http://www.xsscuba.com/tank_steel_specs.html
The Nominal Capacity at 
http://www.xsscuba.com/tank_steel_specs_metric.html is what we need.
15.3 liters should be 0.54 cuft.  @230 Bar the ideal gas is 124.34.

The Z-factor for air at 250 bar and 300 K (little warm for room temp) is 
1.0669.
The Z-factor at 200 bar/300K is 1.0326.  I'd estimate the Z-factor 
around 1.05 for 230 bar.  Just an eyeball would put the "real" around 119.

<<sigh>> and here I wanted to believe the manufacturer especially since 
their 120 tank is listed as having 120 cu ft and costs $25 more at my LDS.
--Steve


So I'm guessing the True Volume from the first web page is the ideal gas 
calculation.  However that implies to me that the actual capacity is 116 
cu ft  (124.34/1.0669=116.55).

However, we are not at 250 bar so looking down at 200 bar with a Z 
factor of