Abstract
The purpose of this review paper is to explain the procedure to measure vacuum pressure quantitatively. This paper also includes following contents, i) concepts of “uncertainty” and “traceability”, ii) obstructions to measure vacuum pressure quantitatively, iii) methods to generate absolute pressure, and iv) practical use of calibration certificate. It is stressed that two points are most important for quantitative measurement of vacuum pressure; to clarify the relation between the pressure indication of a vacuum gauge and absolute pressure, and to evaluate the reliability of the measurement, in other words “uncertainty”, quantitatively.
