The KRISS Primary Vacuum Gauge Calibration Standards: A Review

Abstract

 The calibration of vacuum gauges is mainly carried out in two ways; i) using the primary standards in which the readings of a test gauge are compared with the pressures generated by the standard, and ii) by comparison method in which the readings of the gauge under test are compared with the output signal of a secondary standard. The former type of standards are, usually, large and complicated systems comprising of vacuum pumps, chambers, valves, and gauges etc. while the later type are simply vacuum gauges, with superior qualities, which are attached to a properly designed calibration system. The Vacuum Measurement Lab at Korea Research Institute of Standards and Science (KRISS), Rep. of Korea, maintains primary standards as well as systems for calibration by comparison method. The KRISS primary standards can be used for the calibration purpose in the pressure range from ∼10⁻⁷ Pa to 133 kPa. For bilateral as well as key comparison of these standards, KRISS has participated in the past where its standards have good degree of equivalence and hence international recognition, with other national standards like that of NIST, PTB, NPL(UK), etc. Besides, the KRISS Vacuum Measurement Lab also has comparison system which can be used for calibration by comparison method. However, here the KRISS primary vacuum gauge calibration standards are discussed briefly with the aim to provide enough information to the readers in a single paper.