In the pressure range from 10 mPa to 130 Pa, a fully automated static expansion system made of aluminum has been set up and validated. The principle of static expansion is based on the transfer of a fixed amount of gas from a small volume to a larger volume. Thereby, a well-known lower pressure is generated if the initial pressure and the ratio of the two volumes are known precisely. To reduce the uncertainty in gas temperature the system is built from vacuum components made of aluminum, whose thermal conductivity and diffusivity is higher by more than one order of magnitude compared to stainless steel. The temperature is measured by a total of 90 Pt100 sensors. As a result, relative standard measurement uncertainties between 0.8‰ and 0.12‰ are achieved.

For the high vacuum range from 10^-6 Pa to 10^-2 Pa a new type of ionization vacuum gauge has been developed. Unlike conventional Bayard-Alpert and extractor gauges, the new gauge features well-defined electron trajectories and mechanically robust electrodes. It exhibits excellent stability and linearity resulting in a measurement uncertainty of 1%, a reduction of one order of magnitude compared to the conventional gauges. The gauge can be used as reference or transfer standard. The essential parameters of the gauge geometry and electrode voltages are published in ISO/TS 6737:2023. By adhering to the standard, manufactures can produce gauges with predictable gauge sensitivity and relative gas sensitivity factors without the need for metrological characterization.

Primary standards based on cold atom traps promise a new route to the realization of the pascal in the ultra-high vacuum range by measuring the loss rate induced by collisions with gas molecules. To establish such standards, comparisons with conventional standards must be carried out in order to validate their working principle. The University of British Columbia and the PTB have performed a comparison of a mobile standard based on cold atoms and a continuous expansion system. The comparison covered N₂, Ar and H₂ in the pressure range from 3×10⁻⁸ Pa to 1×10^⁻⁶ Pa. The obtained values of the collision cross sections are compared with values obtained by NIST.

In the semiconductor industry, outgassing from components in vacuum must be well controlled. These contaminants are monitored by quadrupole mass spectroscopy. However, a quantitative measurement of the amount of contamination is challenging as quadrupole mass spectrometers (QMSs) inherently lack stability of their sensitivity. This is particularly problematic when maximum levels of contaminants must be agreed between manufacturers and suppliers. To improve the comparability of outgassing rate measurements, PTB together with IMT and industrial partners has developed outgassing rate reference samples for dodecane and water. By means of an in-situ calibration of QMS, traceable outgassing rate measurements can be achieved.