RMV vs SAC rate

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Fine shearwater should let us choose which to display. And require us to input tank type if we want rmv.

Everybody is happy heh.
 
Fine shearwater should let us choose which to display. And require us to input tank type if we want rmv.

Everybody is happy heh.
Every time the user has to enter something, especially if it is required, the more chance for an error...either because it was entered incorrectly or misunderstood as to what was to be entered. It is a trade-off.

Long ago, I used a device to measure surface waves as part of my job. It was a 1m stainless steel sphere with electronics and batteries inside and an antenna sticking out of the top. The batteries would last about a year. The crusty old Dutch engineer who designed them and sold them welded the two hemispheres together before he shipped the device to you....he said within a year it would be lost or some ship would run it over so there as no reason to allow it to be opened to replace batteries, and once you could open it all the problems began. I convinced him to make me one I could open; I wasn't going to be using it in a shipping channel, and when used it was only for a few days to a week or two. I needed to be able to replace the batteries. He made it, I used it, and only forgot to connect the battery pack before deploying it once. Sometimes, the manufacturer is so intent on making some foolproof he forgets it might also be less usable.
 
SAC vs RMV, who cares what’s called? I think people love to complicate things and this just creates confusion.

I consume x cf3/min at the surface, it’s what matters, from here I can calculate the consumption at any depth, irregardless what name one may assine to it.

One for pressure and the other for volume just leaves room for error in my opinion.

SAC and RMV are closely related, but are not the the same thing.

SAC is expressed at PSI per minute. It’s used to estimate dive time remaining during the dive, or to calculate RMV.

RMV is expressed in Cubic Feet per minute. Mostly used for calculating how much gas is required for a dive, before the dive. However, SAC must be known to calculate RMV.

So they’re interrelated, but not the same.
 
Every time the user has to enter something, especially if it is required, the more chance for an error...either because it was entered incorrectly or misunderstood as to what was to be entered. It is a trade-off.
True but, there's other things that must be set right so what's the difference?
I would like the option.
 
True but, there's other things that must be set right so what's the difference?
I would like the option.
I think that’s what @tursiops said as wel if you read the rest of his post.
 
Here is a response to my inquiry on this subject to Shearwater 2 years ago.

For now we've decided to report based on pressure (psi) and not volume (cu ft) mainly because it keeps simplicity. We agree with your assessment that many technical divers do not find air integration attractive. Concurrently many recreational divers are attracted to the air integration feature and we want to keep things as simple and reliable as possible for them. That said, we always take feedback from customers like yourself seriously. Feedback always plays a role in decisions for implementing new features. Thank you for your note.
 
I just calculate the RMV myself using the provided SAC psi and looking up the rated tank air volume and rated tank max psi.
I then record it in the App under gas notes.
 

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