The claim made in this edit that the graph is in error in the glow discharge region seems to be mistaken.
The graph as it stands is consistent with that in Gewartowski Principles of Electron Tubes page 538, whereas of the sources quoted by 144.82.184.206, the second seems to be plotting a different quantity (the response of a radiation detector) and the first is for me "content is outside your subscription".
I shall revert 144.82.184.206's edit.
--catslash (talk) 20:09, 6 July 2015 (UTC)[reply]