Reaumur scale
— Noun
– English
～ a temperature scale on which water freezes at 0 degrees and boils at 80 degrees
Rankine scale
— Noun
– English
～ a scale of absolute temperature in Fahrenheit degrees; the freezing point of water is 491.69 degrees and the boiling point of water is 671.69 degrees
Richter scale
— Noun
– English
～ a logarithmic scale of 1 to 10 formerly used to express the magnitude of an earthquake on the basis of the size of seismograph oscillations
retinal scanning
— Noun
– English
～ biometric identification by scanning the retina of the eye; "identification by retinal scanning is complicated by eye movements"