SAC differences between AI computer and Manual Calculations

[MarkA]

Sometimes SAC is more useful, other times RMV is more useful. It's good to know how to convert either direction.

Most times metric is more useful.

Time to join the rest of the world and go metric.

 

[Jcp2]

Most times metric is more useful.

Time to join the rest of the world and go metric.

We’ll do that once the world adopts a new reserve currency.

 

[MarkA]

We’ll do that once the world adopts a new reserve currency.

At least the US Dollar is metric. Not like when I was young with 240 pence to the pound. I guess that system worked in the 800’s.

The maths for partial cylinder contents are easier using pressure (bar) and water capacity (litre). Where the original error came from.

 

[tursiops]

Where the original error came from.

Nope. The original error came from ignoring ATA. Nothing to do with metric.

 

[L13]

Nope. The original error came from ignoring ATA. Nothing to do with metric.

10m water => 1bar =>1 ATA , close enough for diving purposes. a lot easier than 33ft water=> 14.7psi => 1 ATA. You can do the RMV math in your head in metric.

Even here in the States, all the competent engineers I know do the engineering in metric and then convert to whatever units requested.

 

[tursiops]

10m water => 1bar =>1 ATA , close enough for diving purposes. a lot easier than 33ft water=> 14.7psi => 1 ATA. You can do the RMV math in your head in metric.

Even here in the States, all the competent engineers I know do the engineering in metric and then convert to whatever units requested.

Sometimes metric is easier, sometimes not. We older engineers use whatever works, convert if needed, do a lot in our head (slide-rule generation), and don't proselytize.

 

[rfwoodvt]

Most times metric is more useful.

Time to join the rest of the world and go metric.

I use metric for cooking and charcuterie.

 

[L13]

Sometimes metric is easier, sometimes not. We older engineers use whatever works, convert if needed, do a lot in our head (slide-rule generation), and don't proselytize.

You are right, I overstated my case. For problems with non-metric inputs and/or non-metric outputs, doing the engineering in metric is not always a good idea. Also when re-using existing engineering it can be a bad idea to switch units (see the recent death due to metric/imperial tank valve specs in another thread).

 

[inquis]

You can do the RMV math in your head in metric

No, you can convert depth to pressure in your head. Very few will calculate RMV in their head for using 153 bar out of a 11.1 l cylinder over 27 minutes at an average depth of 19 m.

Not to mention the op count / difficulty is the same. In imperial, I burned 2218 PSI out of a 2.6 cuft/hundred psi tank at an average depth of 62 ft.

Metric RMV: (153*11.1) / 27 / 2.9
Imperial RMV: (22.18*2.6) / 27 / 2.9

Easy peasy, either way. Wait, let me guess... you don't know what a 2.6 cuft/hundred psi tank is? If you get to "just know" that tank you dived in Mexico was 11.1 liters, then I get to "just know" mine was a 2.6 cuft/hundred psi cylinder.

 

[inquis]

Not sure how this devolved into "gotta use metric". We were discussing SAC and RMV. Use whatever units you like. I'm "bilingual" with respect to units and will converse with you in your native tongue if you aren't.