kPa to in/Hg??

kjones6039 · Post by **kjones6039** » Wed Aug 02, 2006 4:48 pm

What is the relationship between kPa and inches of mercury?

PSIG · Post by **PSIG** » Wed Aug 02, 2006 5:04 pm

101.325kPa = 1 bar = 1 atomsphere = 29.92" Hg (mercury) = 14.6965 psi

Therefore 101.325kPa / 29.92"Hg = 3.3865kPa per inch of mercury. Other way around is 29.92 / 101.325 = .2952"Hg per kPa. Round 'em off for easy figuring.

Bernard Fife · Post by **Bernard Fife** » Wed Aug 02, 2006 5:06 pm

kjones6039,

101.3 kPa is roughly 0 inches of mercury (inHg) at sea level. 0 kPa is -29.92 inHg.

So at sea level on an 'average day':

inHg = kPa / 3.386 - 29.92

or

kPa = (inHg + 29.92) * 3.386

However, vacuum is measured relaive to the ambient pressure (which changes with elevation, the weather, etc.) but kPa is an absolute pressure scale, and doesn't change (which is why it's the preferred system of measurement).

See Eric's page and his very good converter here:

http://www.not2fast.wryday.com/turbo/bo ... rter.shtml

Lance.

kjones6039 · Post by **kjones6039** » Thu Aug 03, 2006 12:37 am

Just the info I needed!!

Many thanks!!!!

Ken