Pressures can be expressed in traditional units (torr/atm; 1 atm= 760 torr), or in SI units (Pa; bar = 100 Pa used instead of atm). Which do you think is better, and why?
2007-12-01 05:50:03 · 5 answers · asked by Facts Matter 7 in Science & Mathematics ➔ Chemistry
I'm flexible, although given the choice I personally prefer atmospheres. It's easy enough for me to remember 1atm=14.7 psi=101,300 Pa=760 torr=, and from that I can convert any pressure unit to any other unit.
Pressure is probably the least standardized unit. I work a lot with HPLC(high pressure liquid chromatography) systems, and even the manufacturers of those can't seem to decide on one unit.
The other day, I opened a brand new Varian column. The test chromatogram reported the back pressure for that column at 1.1 MPa, while the accompanying instructions said that the back pressure shouldn't exceed 5000 psi. I then hooked the column up to a Hewlett Packard HPLC system, which reported the back pressure as 210 bar.
2007-12-01 06:32:12 · answer #1 · answered by Ben H 6 · 1⤊ 2⤋
1 atm = 101.3 kPa = 760 torr To convert set up a ratio between the equivalences above to what you are looking for. For example: convert 850 torr to kPa. Answer: 760 torr / 101.3 kPa = 850 torr / x You now have an equation you can solve. This method works because in the first ratio the numerator and denominator are equal, so in the second ratio the numerator and denominator are also equal so x must equal 800 torr, it just has the units of kPa, which is what was needed. In the above problem x = 113.3 kPa.
2016-04-07 01:55:32 · answer #2 · answered by Anonymous · 0⤊ 0⤋
One of my pet hates - units ; I believe strongly that the whole world should work in SI and anything else should be banned! This would eliminate a lot of "stupid" conversion mistakes!
Therefore my answer will obviously be Pa = (N/m^2) !!!
Once you got a feel for it it doesn't hurt anymore either.....
2007-12-01 05:56:45 · answer #3 · answered by klimbim 4 · 1⤊ 0⤋
I have to say that my personal preference is to use SI units as I find it easier, however I think it is all down to the individual and what suits them best.
2007-12-01 18:11:01 · answer #4 · answered by Anonymous · 0⤊ 0⤋
I believe the best and easier to use is Atmospheres.
From that, any of the others can by calculated easily.
2007-12-01 06:08:00 · answer #5 · answered by Norrie 7 · 0⤊ 1⤋