Helium Shortage has ended ...

[Manatee Diver]

They can pull up a calculator if they have Internet access. Hard to do while diving...

I don't remember the last time I had to do a force calculation underwater.

In fact if you are doing complex calculations underwater, you are probably doing it wrong. As underwater where you have to deal with narcosis isn't the place to be doing things like that.

 

[Angelo Farina]

I don't remember the last time I had to do a force calculation underwater.

In fact if you are doing complex calculations underwater, you are probably doing it wrong. As underwater where you have to deal with narcosis isn't the place to be doing things like that.

For rec diving I agree entirely. But I am a scientific diver, too...
And often you have to evaluate if your tank has enough air (bars) for filling a bag for lifting an object having some mass (hence weight) and some buoyancy...
Which is trivial in SI, not so trivial (at least for me) in Imperial units.

 

[Manatee Diver]

For rec diving I agree entirely.

Which is the context of the argument as almost all scientific pursuits use SI.

 

[tridacna]

It annoys me that in some areas when the US presents in metric, they present differently.

Example: Blood glucose concentration for diabetics is measured in mmol/L everywhere but in the US where it is measured in mg/dL. Ditto for cholesterol or triglycerides. What makes this especially confounding is that conversions are not straightforward. You have to know the molar masses of each molecule to make the conversions.

I wonder what precipitated such stupidity in the US. Even when converting to metric, they elected to be remain different.

 

[Superlyte27]

My supplier called me yesterday to tell me my new cost on helium. .46/cu’

 

[Addison Snyder]

My supplier called me yesterday to tell me my new cost on helium. .46/cu

Who's your supplier?

 

[Superlyte27]

Who's your supplier?

Airgas

 

[ELCAM]

Airgas

What was your price before?

 

[BRT]

As said, it is not trivial. It SEEMS trivial..
If you search on the Internet, you easily find unit converters, which state that 1 kg = 2.20462 lb
So apparently it is just matter of multiplying or diving by that factor.
The problem is that in SI you need to enter the MASS in kg in the formulas for doing calculations, while in the US system the pound is a measure of FORCE, not mass. So, apart converting the numerical value of lb to kg or vice versa, YOU NEED TO MODIFY THE FORMULAS, as they are dealing with different physical quantities.
If you are just purchasing a beef steak at the butcher, the change from mass to force is inconsequential: if you make the unit conversion correctly, you will come out with the very same beef steak you wanted to buy.
But whenever the mass/weight has to be used in a formula for doing calculations (as it often happens for scuba diving calculations), you must take into account that the two quantities measure different physical properties, and hence they must be used in different formulas...

Uh huh. Please tell me when a KG isn't equal to 2.2 earth pounds. And tell me how you determine how many kilograms of mass you have. When was the last time you measured KG except as a force? Nonsense.

 

[Manatee Diver]

Uh huh. Please tell me when a KG isn't equal to 2.2 earth pounds. And tell me how you determine how many kilograms of mass you have. When was the last time you measured KG except as a force? Nonsense.

In order to get the static force in metric you have to multiply by the gravity of earth. While pounds already factor in the force of gravity.