noun
The scientific study of measurement, including standards, instruments, and methods.
計測学は、正確な測定のための理論と技術を扱う学問です。
Metrology is a discipline that deals with the theory and techniques for accurate measurement.
計測 refers to measurement or instrumentation in general, while 計測学 specifically denotes the academic field of metrology.
Compound of 計測 (measurement) + 学 (study, -ology). The exact historical derivation is uncertain, but the term follows the standard pattern for naming academic disciplines in Japanese.