Altimeter - Barometric Scale

[bse7entn]

Greetings,

Does anyone have a photo of what the barometric scale looks like on the inside of an altimeter? Something like AN 5760? I'm not a pilot and I don't know what the low and high for the scale goes to. I found one photo online but it's so small the type is illegible.

 

[Wurger]

Do you mean a such AN 5760 altimeter ?

 

[bse7entn]

That would be the one yes.

 

[Wurger]

Ok.. what is the problem you are trying to get sorted out?

 

[bse7entn]

The small window with the barometric scale. What values do the scale go to? I've been looking for a photo of that disc but no success yet.

 

[Wurger]

Do you mean the small scale on the right with the number 304 seen above or with the 309/310 seen below?

 

[bse7entn]

Yes, that's it.

 

[Wurger]

Sorry for the delay but here is almost ten past 5 o'clock in the morning. I should have hit the sack long time ago.

The barometric scale dial range depends on the measurment unit the altimeter was set and the type of an altimeter. Usually it can be 28.0 to 31.0 in HG or 946 to 1060 in mb or hPa.

 

[bse7entn]

Oh wow. Thank you for looking. Definitely wasn't something needed tonight but very appreciated.

 

[Wurger]

My pleasure.

 

[bse7entn]

Thanks again. Not having this info was a stopping point.

 

[Wurger]

 

[fliger747]

The 31" was sort of a "problem" for the FAA when the altimeter hit over 31" one Winter back circa 1990. We got grounded in Nome till the pressure again decreased. The issue was IFR flight without an accurate altimeter setting. Actually not to much of a danger as it was clear everywhere and pressure over 31" would make you high, not low.