Purpose and scope of the project


Modern vacuum systems not only have to be robust and easy to operate, they also have to meet tough demands in terms of performance. 

Industry and research often need a complete characterisation of the vacuum process environment, which includes (in addition to the total pressure) the gas composition i.e. which species are present in the vacuum and their partial pressures. Therefore the "cleanliness" of a vacuum – or more technically the absence or sufficiently low partial pressure of specific gas species or vapours – is vital. Quadrupole mass spectrometers (QMS) are mainly used for this purpose. Although oil –free vacuum pumps and other components have improved cleanliness considerably, components can still be a source of unwanted gasses that can be released or "outgassed" into the vacuum. Outgassing rates are therefore a vital quality assurance figure in vacuum technology. Before this project, there was no internationally standardised way to measure such rates and to establish their traceability to the SI system of units, neither there were standardized procedures to characterize or calibrate QMS with a minimum of traceability to the SI.


We wanted to improve this situation by establishing internationally acknowledged ISO Technical Specifications (TS):  One TS was developed to characterize and calibrate quadrupole mass spectrometers, the second TS to measure and report outgassing rates.


The ISO Technical Committee (TC) 112 "Vacuum Technology" is responsible to develop written standards and technical specifications in the field of vacuum technology. The Working Group 2 (WG 2) within ISO TC 112 prepares standards for vacuum instrumentation. Our project closely worked together with WG2 and used the results of the Opens external link in new windowformer project EMRP IND12.

However, in order to make the two future TS a success, a much broader community had to be involved in the development process, in particular manufacturers of QMS, service companies working with QMS and users of QMS in industry, mainly the semiconductor industry, and in large research facilities as fusion machines, particle accelerators, free electron lasers etc.

We also included scientific investigations testing the methods described in the early drafts of the two TS. The present state of the art was presented and assessed in a workshop that took place from January 30 to February 1, 2017, in Berlin in the premises of PTB.

Are you complaining that your QMS does not repeat the catalogue parameter values?

Do you want to receive or report reliable outgassing rate data?

Then you are the right person to use the TS 20175 and TS 20177! Technical Specifications are standards under field test. So, if you have any suggestions for improvements and other comments: Opens internal link in current windowContact us.