Development of a transportable apparatus for vacuum gauge calibration

• A novel transportable apparatus for vacuum gauge calibration is developed.
• Its calibration range is from 1.96 × 10−5 Pa to 1.03 × 105 Pa.
• It has the advantages of simple structure, high efficiency, low cost, light weight.
• Its performances (ultimate pressure, pumpdown, static charateristics) are given.
• Its metrological characteristics (stability, repeatability, uncertainty) are given.

A new ultrahigh vacuum transportable apparatus for vacuum gauge calibration in the pressure range from 10−5 Pa–105 Pa is developed. On the basis of modularization design, it can be easily extended and assembled. A standard pressure pstd with various gas species can be generated by means of pressure attenuation module which is easy to introduce the corresponding calibration gas through an orifice. The standard pressure pstd in the range from 10−5 Pa to 10−2 Pa could be obtained by changing the upstream pressure from 1 Pa to 103 Pa with an uncertainty of approximately 2.4%. At the same time, calibration can also be performed by direct comparison with a reference gauge either in static or stationary equilibrium. The ultimate pressure could be in the level of 10−6 Pa typically. The pumpdown characteristic and outgassing rate of the apparatus after exposing to atmospheric pressure are presented. The main metrological characteristics of the apparatus are given. The size and weight of this apparatus are 475 mm × 420 mm × 800 mm and 37.8 kg, respectively. Its calibration range is from 1.96 × 10−5 Pa to 1.03 × 105 Pa with the relative combined standard uncertainty from 2.8% to 0.40%.