Proficiency Testing

Laboratories are committed to optimum quality of their instruments, procedures and measurement capabilities. To do this, they usually work with internal inspections. However, external validation is indispensable. VSL provides this, in the form of proficiency tests.

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The importance of proficiency testing

Systematic measurement deviations that develop over time cannot be detected by internal audits alone. Several accreditations, as well as ISO/IEC 17025:2017, therefore require laboratories to participate in Proficiency Tests (PT schemes) or interlaboratory comparisons (ILC). This involves an anonymous comparison of measurement results from multiple laboratories (benchmarking) to identify any deviations. VSL is an accredited PT provider.


Proficiency testing in practice

During a Proficiency Test, all participating laboratories perform the same measurements and data analyses. The results are compared and compiled into a report in which each participant is assigned a unique code. Participants only know their own code, allowing them to anonymously compare their results with those of other laboratories. We treat the data confidentially and only disclose them to the laboratory itself.

Participation in proficiency tests is an investment in reliability, operational security and confidence in one’s own capabilities. It also enables laboratories to meet the requirements for accreditation and ISO/IEC 17025:2017.

Laboratories that are committed to quality also consider it important to participate in PT schemes because:

  • they allow them to independently verify and confirm their own performance
  • they provide input for strategic marketing decisions because they show how the laboratories perform compared to others
  • they either confirm the laboratories’ satisfactory performance or provide a warning of possible problems that require investigation
  • the laboratories see PTs as a quality and risk management tool
  • they recognise the educational role of PTs
  • they meet the requirements set by regulatory and accreditation bodies.

Would you like to know more about our services?

Our experts are happy to help.

Koen Haije
Senior Account Manager

Need another proficiency test?
Depending on demand from the market, we can set up proficiency tests with a diversity of ranges, artefacts and technologies. Another possibility is to organise a bilateral comparison with VSL. Just let us know.


Planned proficiency tests
VSL carries out proficiency tests in several areas. These range from pressure, mass and viscosity to temperature, electricity and length.

Proficiency testStart dateRegister untilRegister form
Natural GasOctober 1, 2023September 1, 2023 FullRegistration closed
FrequencyDecember 1, 2023November 1, 2023Register
Mass E2December 1, 2023November 1, 2023Register
Humidity TransmitterDecember 1, 2023November 1, 2023Register
DataloggerDecember 1, 2023November 1, 2023Register
Refinery GasDecember 1, 2023November 1, 2023Register
NAWi BalanceJanuary 1, 2024December 1, 2023Register

Our areas of expertise