Mares Dive Organizer consumption spike at start of dive?

[brutus_scuba]

I challenge you to articulate your argument better! The percent change is not part of the equation! The tank is not compressible so the pressure does not change with depth! The SAC takes the volume of gas you are breathing divided by the ambient pressure, and does not relate to a change from the last sample time!

My guess would be that it has to do more with their algorithm than reality! I would guess that their sample rate is higher than your respiratory rate! So they use many many samples to calculate your breathing with a weighted average! However, that would drive your readout low so they compensate with a false backloaded history in the model!

All this speculation of mine though should be prefaced with this, I can't really see the graph well on my phone!

 

[Kharon]

But you can be pedantic. Don't remember saying anything about compression of the tank. You simply breath more air as water pressure increases. That may look like increased consumption if the software doesn't take depth into account.

 

[brutus_scuba]

If the software was giving you a straight out respiratory minute volume calculation (not taking into account depth) than you wouldn't see a spike it would just be a graph that generally increased with depth and decreased on ascent assuming breathing rate stays otherwise constant!

 

[kr2y5]

I would be surprised if this is just this particular computer... as you submerge in water colder than air and descend, the air in the tank cools down, and as a result, the pressure decreases slightly in a short amount of time. Unless the computer is measuring the temperature of the air in the tank, it has no way to account for that factor. I would not worry about a spike in SAC at the beginning of the dive.

Hello, I've noticed that every single of my dives logged with the Icon HD Net Ready starts with a huge consumption spike in the range 122 - 190 L/min.