A Comparison of Ignition Characteristics of Diesel Fuels as Determined in Engines and in a Constant-volume Bomb
A 1939 technical report from the National Advisory Committee for Aeronautics, compiled for engine researchers, comparing diesel fuel ignition behaviour measured in running engines and in a constant-volume bomb. The first picture is a line graph of ignition delay against air density at bomb temperatures of 870 and 1,155 degrees Fahrenheit, with curves marked by open and filled symbols descending from left to right. The second is an oscilloscope trace with a flat baseline that rises in a stepped, jagged curve at the moment of ignition, giving a designer a clean graphic motif of a sudden onset.
