Assertion: difference frequency | /r/HasProperty | measured
Facets:
value: directly
type: MANNER
Source sentences:
text: Above these frequencies the signal to be measured is combined in a mixer with the signal from a local oscillator, producing a signal at the difference frequency, which is low enough to be measured directly.
text: From light of opposite ends of the broadened spectrum the difference frequency is generated in a nonlinear crystal, and a heterodyne beat between this mixing product and light at the same wavelength of the original spectrum is measured.