INTERLABORATORY COMPARISONS FOR INSPECTION BODIES AND TESTING LABORATORIES
Obligations and participation procedures in compliance with ILAC P9:01/2024 policy
TABLE OF CONTENTS
If your Inspection Body or Testing Laboratory performs in-house calibration of the measuring instruments used for verifications or tests, it must now participate in mandatory Interlaboratory Comparisons on calibration of working standards on a periodic basis.
SA Quality for Metrology can assist you by offering various comparisons specifically organized for this purpose.
Here you will find all the information you need on these requirements and how you can fulfill them with our support.
Discover our Interlaboratory Comparisons dedicated to Inspection Bodies and Testing Laboratories!
Explore our ILC calendar and look for the comparisons marked with the following codes:
• Inspection Body ISO 17020
• Testing Lab ISO 17025
Discover our Interlaboratory Comparisons dedicated to Inspection Bodies and Testing Laboratories!
Explore our ILC calendar and look for the comparisons marked with the following codes:
• Inspection Body ISO 17020
• Testing Lab ISO 17025
Why Inspection Bodies and Testing Laboratories must participate in Interlaboratory Comparisons
The ILAC P9:01/2024 policy stipulates that the following organizations:
- Inspection Bodies (IBs), accredited in accordance with ISO 17020 standard;
- Testing Laboratories (LABs), accredited in accordance with ISO 17025 standard;
that perform in-house calibration of the working standards utilized for their verifications, are required to participate in Proficiency Testing / Interlaboratory Comparisons (PT/ILCs) on the calibration of the standards themselves.
Procedures and timelines for IBs and LABs participation in PT/ILCs
Each national accreditation body establish regulations for the participation in PT/ILCs of its country’s IBs and LABs, as well as for the planning of subsequent periodic participations.
Why are PT/ILCs on calibration useful for for IBs and LABs
PT/ILCs are essential tools for bodies performing in-house calibration of their measuring instruments.
Instrument calibration ensures the measurement traceability with reference to national and international standards, as well as maintaining instrumental uncertainty, a component of the uncertainty of verification and testing results.
According to ILAC P9:01/2024 policy, participation in PT/ILCs is a fundamental requirement to ensure the quality and consistency of measurements performed by accredited IBs and LABs, as they guarantee the validity of the measurements and demonstrate technical competence in the calibration of work samples (travelling samples).
How should PT/ILC be planned by IBs and LABs?
The ILAC P-9:01/2024 policy and ILAC G27:20219 guide establish the requirements for participation in PT/ILC. The document states that IBs and LABs must:
- Develop a participation plan for PT/ILCs that ensures the representativeness of the measured quantities and covers their accreditation scope.
- Ensure participation occurs at an appropriate frequency, based on metrological risk and the complexity of the measurements performed.
- Choose PT/ILC organized by qualified providers, compliant with the ISO/IEC 17043 standard.
- Document and analyze PT/ILC results to implement corrective actions in case of unsatisfactory outcomes.
Which measurement fields should be chosen?
To ensure adequate metrological coverage, IBs and LABs must select PT/ILC based on the critical quantities within their accreditation scope. According to the ILAC P9ILAC P-9:01/2024 policy, the selection should be based on:
- The type of instruments used.
- Measurement ranges.
- Operating conditions.
- Availability of recognized PT/ILC.
How Interlaboratory Comparisons on calibration are conducted
ILCs are sequential tests that compare the performance of a certain number of participating laboratories or other bodies. ILCs are organized by special suppliers called Proficiency Testing Providers (PTPs).
During an ILC, the same sample is calibrated by participants in succession: the first one performs their measurements, then sends the sample to the second one who conducts theirs, and so on until the last one. At the beginning and end of the cycle, the sample is calibrated by a reference laboratory to assign a reference value and assess its stability over time.
The results are collected and compared with the reference value to evaluate calibration’s precision and accuracy of each participant, using the En compatibility index (Normalized Error).
Finally, a report with conclusions is prepared and sent to each entity for result analysis and the definition of any corrective actions.
How to select the PT/ILC provider
PT/ILCs are organized by specialized bodies called Proficiency Testing Providers (PTPs). Each accreditation body establish national criteria for the selection of PTPs in its country. Anyway, in general the providers should meet the following requirements:
- They must be accredited according to ISO/IEC 17043 standards, by accreditation bodies signatories of the EA, IAF, and ILAC International Mutual Recognition Agreements (MLA/MRA).
- They must be included in the EPTIS database.
• SA Quality for Metrology is an accredited Proficiency Testing Provider (Accredia PTP certificate no. 0024P).
• Accredia is the only accreditation body for Italy. In accordance with EA, IAF and ILAC MLA/MRA, we are authorized to operate at an international level.
• Our PTs are included in the EPTIS database.
How we can help you: our Interlaboratory Comparisons for IBs and LABs
To support accredited IBs and LABs which must participate in the PT/ILCs required by ILAC P9:01/2024 policy, we have organized a series of comparisons specifically dedicated to this purpose.
These PT/ILCs concern the measuring instruments most commonly used by IBs and LABs, such as analytical balances (NAWI), reference weights and tanks, micropipettes, thermometer probes.
Explore our Interlaboratory Comparisons calendar and look for those relevant to your IB or LAB. You will find them marked with the following special codes:
- Inspection Body ISO 17020.
- Testing Lab ISO 17025.
Click on the SHOW button of the ILC you are interested in, to open the corresponding presentation and technical card.
We are also working on additional ILCs of this kind, which we will make operational as soon as the technical details are finalized. For updates on the latest news, we recommend checking our website periodically or contacting us directly.
How to participate in our PT/ILCs?
To register for and participate in our PT/ILCs, you need to access our PT Portal, which is located in the reserved area of our website.
You can access the reserved area by creating an account. Through the PT Portal you can easily manage all comparisons’ phases: registration, document sending, and execution.
If you have any doubt or need more information, please do not hesitate to contact us.