Air consumption rate and translation

Air consumption rate and translation

Postby AgentMax » Wed Feb 12, 2014 11:54 am

Hello,

I'm syncing to Dive log manger from my Atomics Cobalt computer.

I noticed that the air consumption rate on the cobalt is much higher than in dive log manager.
Both set to 12 liter tank.

Example:
Cobalt: 12 liter. Starting pressure 183bar. End 52bar. Usage 1570 liter = 18l/min.
Dive log: 12 liter. Starting/End same. 16,38l/min.
Dive time 38 min. average depth 14,3m.

Most of the time the difference ist around 2 l/min.

And one last thing.
What about a german translation of your software? I'd like to have both (Mac/iOS) in my native language.
If you need someone to do that, feel free to ask me. I really would like to have it in german. Even if I have to translate it.


Thanks for making this great software,
Michael
AgentMax
 
Posts: 2
Joined: Wed Feb 12, 2014 11:37 am

Re: Air consumption rate and translation

Postby support » Wed Feb 12, 2014 2:31 pm

Hi Michael,

Couple of things that can cause the difference.

First, the Atomic Cobalt is the only computer that we support that gives you the average depth of the dive when you download a dive. When we draw the "average depth line" on the profile display, we just do the basic calculation over all the samples we have. The sample interval the Cobalt uses is pretty "coarse" at 30 second intervals, so if you think about your depth profile over time, a 30 second interval doesn't give you a very accurate average depth. But the Cobalt itself knows your depth while you're diving of course and so the average depth it delivers with the profile information on download is much more accurate than our own calculation from the samples. So we use *that* average depth when calculating the SAC, *not* the average depth shown on the DLM profile display. Right now, there is no good way for you to see the former since the Cobalt is the only one that does this. If you are motivated, I can tell you where the file is that it is stored when you download.

Second, when we're calculating the SAC rate, we don't use the Dive Time as entered in the Dive Details. We use the time as calculated from the profile as the actual dive time. Since the Dive Details time is shown only in minutes, it does not take fractional minutes into account. So if you look at the profile for your example dive, see how long the profile is. With the Cobalt, we see generally two or three more samples after the listed dive time. So if your dive is shown as 38 minutes, you probably have 39 minutes of profile. And you'll probably see that your depth does not become "zero" until the last sample. So "generally" (but not necessary always), the profile is a more accurate representation of your dive time.

The Cobalt probably uses the more accurate average depth in it's calculations, but I thought it was important to mention if you are doing the math yourself that you'll see a difference. The likely cause for the difference is the dive time. It can be a minimum of 1 minute and as much as 1.5 minutes longer using the profile and waiting for a zero depth. The Cobalt may use the time based on when you reach less than 5 meters or 15 feet - I'm not sure what they use. But since it is reporting your Dive Time as 38 minutes, I'm betting that they use that number.

What about a german translation of your software? I'd like to have both (Mac/iOS) in my native language.


Ooooooooo, I'm so sorry about that. We have been saying "soon" for a while now and we still haven't done it :( For German or any other language. Once one is done, the rest become easier. Unfortunately there are always so many features that we want to add and "internationalization" just keeps getting pushed down the priority list. We have many German users who have made the same offer, we just haven't done it. The good thing is that MacOS 10.9 added some great new features to make it less work for us! So we were kind of waiting for that for awhile. Maybe now if we wait long enough, Apple will figure out how to just make it happen magically with no work on our part? :lol: Just kidding. It's still on the list.

Thanks for your understanding,
Janice
support
 
Posts: 550
Joined: Wed Mar 31, 2010 4:35 pm

Re: Air consumption rate and translation

Postby AgentMax » Wed Feb 12, 2014 4:04 pm

Thanks for your reply.
I set the cobalt to a sample time of 15 seconds. So its more accurate.

I compared the data in my cobalt and in DiveLog.
The dive time in the computer is 39 Minutes and the profile ends. depth 0,7m.
In DiveLog manager the dive time is 39 Minutes but the profile is 1 minute longer till 0,4m.

DiveLog is average depth 7 meters.
Atomic is 7,6 meters.

After your explanation I assume that the cobalt air time is not more accurate?
Cobalt uses only a "not definded" window of the dive time to calculate the value and DLM is using the whole dive time.
Could you implement a way to correct the value in DLM if I or someone else prefer the cobalt value?

Great to hear that you're working on a german translation. Hope to see it soon :D ;)


EDIT:
Got one more question.
In "Location" tab, if I add a dive site I'm not able to add it to a city (the city that is shown in the upper right of the dive site). Or add a city to a country.
There is no drop down menu to edit that correlation.

EDIT 2:
Found the "problem". Had to edit all dives with that location/site and set it everywhere equal :)
AgentMax
 
Posts: 2
Joined: Wed Feb 12, 2014 11:37 am

Re: Air consumption rate and translation

Postby support » Sat Feb 15, 2014 10:36 am

After your explanation I assume that the cobalt air time is not more accurate?
Cobalt uses only a "not definded" window of the dive time to calculate the value and DLM is using the whole dive time.
Could you implement a way to correct the value in DLM if I or someone else prefer the cobalt value?


I think that "accurate" is in the eye of the beholder. There can not be any "absolutes" in these kind of things, only personal preferences. So generally, using the longer dive time as we do, would give you a better result. Using the shorter dive time as the Cobalt does, will give you a worse result. But it doesn't really matter what the exact number is, you really just want to look at the changes to it over time. And you want to be able to look at a specific dive and see whether the number is bigger or smaller than another dive you want to compare against.

One thing we could do is add a global preference to have the SAC rate calculated from the user entered Dive Time instead of from the profile. That way, a user could see how changing the total dive time affected the SAC. We'll add it to our list of "things to do" eventually :-)

In "Location" tab, if I add a dive site I'm not able to add it to a city (the city that is shown in the upper right of the dive site). Or add a city to a country.
There is no drop down menu to edit that correlation.


Yes. This is meant to just show the "default" City to be used for that DiveSite (and the "default" Country for a City). And this is the default that will be used the next time you enter a dive with that DiveSite(City). The correlation is made on the DiveDetails page of the Dive itself. So if you enter a dive and set the DiveSite to "Aquarium", and then enter the City and Country afterwards, then the next time you enter another Dive and set the DiveSite to Aquarium, it will automatically fill in that same City and Country. Which may or may not be what you want because "Aquarium" is such a common name for a DiveSite that you may have different dives there but in different Cities and Countries!

Hope that clarifies.
Janice
support
 
Posts: 550
Joined: Wed Mar 31, 2010 4:35 pm


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