[mrusnak]

My question is in regards to having a manometer fluid other than water or mercury. If the fluid in an open-ended manometer was heptane, how do you convert mm heptane to atm?

[Borek]

What is pressure definition?

[gunasankar]

First findout the liquid column of heptane which is equivalent to 1 atm.As we know 1 atm equals to 10,330 mm of water column. If you know the sp.gravity of heptane at the respective temperature (say as 0.730), you can convert the water column in to hepatne column by dividing it by sp. gravity of heptane. For this case 1 atm = (10330/0.730) =14150.68 mm of heptane column.

I think this will fulfil your requirements.

Gunas