Assertion: unit | /r/HasProperty | based on tungsten kα 1 line
Facets:
value: as a standard
type: MANNER
Source sentences:
text: Before 1965, most x-ray wavelengths were expressed in terms of the X-unit, which is approximately 10-13 m. The X-unit has been superseded by the A* unit, which is based on the tungsten Kα 1 line as a standard.