Thank you! I
never would have figured this out on my own. These marks appear on a lot of altimeters. But it did not occur to me that since the main dial only covers 1000m, they could not be used for very much.
Now a follow-on question. I have seen diverse instrument markings. But there is little consistency across aircraft. These markings are useful, and for example the US went to more and more of them over the course of the war.
For example on one He 111 engine instrument panel, there are:
Hand-marked temperatures at 40 and 80 degrees C. Presumably these are high and low limits. (Gauge label = drücken Eintr. Temp. = ??)
A metal placard showing maximum temperatures at different altitudes.
RPM gauge with hand-marked limit at 2100 rpm. Presumably this is normal operating level.
Question: does anyone know history/use of such markings? Why weren't they used more widely, especially as less trained pilots became common?
Question2: The instruments are numbered eg M50, M52. Are these original labels, or added later by archivists?
thanks for any insights.
Roger
Higher resolution version of the panel is:
http://www.cockpitinstrumente.de/dow...0panel%20d.JPG