Units of measurement for manifold pressure

[AbortedMan]

So lately I've been flying in formation/leading with regulars and friends online and when we're in the VVS aircraft I'm at a complete loss of what I should be calling the manifold pressure unit of measurement when notifying my wingman of what engine settings I'm flying at...is it lbs/inch (seems unlikely..80lbs of manifold pressure is insane), inches of mercury (also unlikely given the numbers on the gauge)?

 

Someone in TS suggested it was "donkey farts", but that doesn't seem right.

 

Does anyone know what the correct unit of measurement nomenclature is so I can stop saying "I'm flying at 8 and a half thingies/whatevers"?

Edited May 8, 2014 by AbortedMan

[Matt]

I think "800 mm mercury", "1200 mm mercury" etc. would be the correct term.

[Rama]

Normally it should be in mmHg (mm mercury)

[VR-DriftaholiC]

760mm being 1 atmo. 

Edited May 8, 2014 by driftaholic

[6high]

Interesting...mm/HG. Anyone care to elaborate on the technical background (short and for a woodworkers mind pls, otherwise i will prefer to set my mind to "donkey fart" )?

Thank you!

6

[LukeFF]

Interesting...mm/HG. Anyone care to elaborate on the technical background (short and for a woodworkers mind pls, otherwise i will prefer to set my mind to "donkey fart" )?

Thank you!

6

 

What is it you want to know? Wikipedia has a page that describes it quite well.

[6high]

Thank you Luke, i just visited that page. Very interesting.

I guess i expected a nice little summary from someone, lazy me

[AbortedMan]

Thanks fellas, we were speculating it was mmHg...it just didn't add up since 80mm is absolutely nothing, but the gauge being in denominations of x10 makes a bunch more sense....shoulda caught that.

[LukeFF]

mm Hg, as the Wikpedia article alludes to, is still widely used today in the medical field. When you have your blood pressure measured, for instance, it's being measured in mm Hg.