Method of Testing Oxygen Regulators
This is a 1935 NACA technical note, published as a government aeronautical research report, that sets out a laboratory method for testing aircraft oxygen regulators. Its two plates show a schematic of the test apparatus, with a gas meter, vacuum tank, pump and oxygen cylinder, and a photograph of a modified gas meter. For a designer the drawing offers a clean, labelled technical diagram style with plain line work and small lettered callouts, while the photograph shows a dark, heavily detailed metal instrument with a glass-fronted dial.
