vernier scale
Definition
Noun: A secondary, movable scale that slides parallel to a main, fixed measuring scale. It is used to obtain precise fractional readings of the main scale's smallest divisions, significantly increasing the accuracy of a measurement.
Usage
The vernier scale is used in conjunction with a main scale on precision instruments like calipers, micrometers, and barometers. To take a reading, one aligns a mark on the vernier scale with a mark on the main scale. The position of this alignment indicates the fractional part of the measurement beyond the last whole division on the main scale.
Examples
Advanced Usage
- Vernier Acuity: In optometry and physiology, this term refers to the human eye's ability to perceive a slight misalignment between two lines or gratings. It is named for the vernier scale because it describes the high precision of spatial discrimination, much like the scale's function.
- Digital Vernier: Modern digital calipers often simulate the function of a traditional vernier scale electronically, providing a direct digital readout while still being based on the same sliding measurement principle.
Variants and Related Words
- Vernier Caliper (n): A measuring instrument consisting of a main scale and a sliding jaw with a vernier scale, used for taking precise internal and external measurements.
- Vernier (n): Often used as a shortened form to refer to the vernier scale itself or an instrument equipped with one (e.g., "Read the vernier").
- Nonius (n): A historical term, largely synonymous with "vernier scale," named after its Portuguese inventor, Pedro Nunes (Latin: Petrus Nonius).
Synonyms
- Auxiliary scale
- Fractional scale
Related Phrases and Concepts
- Main Scale: The primary, fixed scale against which the vernier scale slides.
- Least Count: The smallest measurement that can be taken with an instrument; for a vernier scale, it is the difference between one main scale division and one vernier scale division.
- Zero Error: A condition where the zero mark of the vernier scale does not align with the zero mark of the main scale when the measuring jaws are closed, requiring a correction to the final reading.
Noun
-
a small movable scale that slides along a main scale; the small scale is calibrated to indicate fractional divisions of the main scale
Khám phá thêm
Các từ liên quan
Từ đồng nghĩa
