Quote:
Originally Posted by bdhill1979  If I remember rightly it is worded as "partially evacuated" in the instrument flying Handbook. I think it also says that the disk is Bronze or a bronze alloy.
Too tired/lazy to look it up though. |
yeah, its not in there
well its 10Kpa below standard ath. pressure. 10Kpa converts to 2.95inHG@0c, so that means at 8,000 on a standard day the pressure inside the aneroid wafer is 18.9 which makes it partial vacuum since its lower then the pressure of outside.
damn that was confusing as #### when I had to convert all those figures haha.
however, that is for 'aneroid barometer' and not specifically aneroid wafer for altimeter' but its close enough, and its the same concept. so its def partial vacuum.