Definitions for "Ratio scale"
Some scales are given as a ratio, variously written as either a ratio (i.e., 1:300) or a fraction (i.e., 1/300). The number on the right of the pair indicates how many units (inches or centimeters) on the original are equivalent to one unit on the replica. For example, with a 1:300 scale miniature, if the miniature is 1" long, then the original was 300" in length. In spoken English, you would say 1/300 as "one [pause] three hundred scale."
A measuring system having the property that ratios of the numbers assigned accurately reflect ratios of the magnitudes of the objects being measured.  This means that a behavior assigned a number of, say, 10, must have twice the magnitude of a behavior assigned a number of 5. Effectively, this requires that there be a true zero, a score that means the behavior is absent. Ratio scales in psychology are almost always physical scales employed to capture behavior, such as the use of response latency to measure task difficulty. Typical “psychological” dimensions, e.g., intelligence or attitude, do not have a “zero” point.
a scale of measurement that indicates the ratio of scores to one another. (641)