vacuum vs pressure

[R Cubed]

Right then imagine two chambers with actuating rods coming out of them one to push out on pressure and one to push out on vacuum, would 20" Hg vacuum give the same force on the rods as 20psi ?

[Richard Farrant]

would 20" Hg vacuum give the same force on the rods as 20psi ?

 

the answer is no ........ here is what Hg and PSI are equal to;

1 inHg = 0.491 098 psi, or 2.036 254 inHg = 1 psi.

[Paul H]

No sadly not - the unit of measurement is different. 14.6 psi is just about the same as 30 in Hg. You could measure a vacuum in psi if you wished though.

 

 

[R Cubed]

the answer is no ........ here is what Hg and PSI are equal to;

1 inHg = 0.491 098 psi, or 2.036 254 inHg = 1 psi.

 

All very interesting, thanks

 

No sadly not - the unit of measurement is different. 14.6 psi is just about the same as 30 in Hg. You could measure a vacuum in psi if you wished though.

 

Yep, I realized the units are different but thought there must be some kind of similarity between them and here you two go and deliver the goods.

 

All these calculations are all very interesting, just goes to show they knew what they were doing back then didn't they

 

Thanks very much.