What is the atmospheric pressure of helium

[bigiron]

What is the atmospheric pressure of helium ?

When using Boyles law calculator http://www.endmemo.com/chem/boyle.php it is required that we know the atmospheric pressure of helium ?

By calculating the volumes of pressurized helium within following cylinders I have found the atmospheric pressure to be approximately 1.47 Bar.

 

Cylinder 1

150cm x 11.5cm Radius - contains .0035m3 of helium @ 200 Bar therefore the initial volume should be 1.37 Bar

Cylinder 2

33cm x 5cm Radius - Contains .0025m3 of helium @200 Bar therefore the initial volume should be 1.42 Bar

Cylinder 3

91cm x 7cm Radius - Contains .0149m3 of helium @200 Bar therefore the initial volume should be 1.64 Bar

 

Is this correct ?

Edited July 6, 2011 by bigiron