Conclusion

Understanding vacuum is a necessary corollary to mastering its measurement. First and foremost, vacuum can be understood on a logarithmic scale, as the traceability of its measurement is established over fourteen decades below atmospheric pressure. Some vacuum gauges are even capable of measuring over six decades with the same performance. What's more, whether considering primary vacuum measurement methods or direct measurement with a vacuum manometer, the nature of the gas must be taken into account (except for manometers whose principle is based on mechanical deformation). Finally, the measurement configuration is often that of a stationary equilibrium: in a vacuum installation, the pressure field that is established depends on the location and size of the sources of gas emissions and pumping. As the vacuum manometer can rarely be positioned exactly at the required point, the pressure...