ISO 17025: 2017 Clause 6.4 Equipment (6.4.10 & 6.4.12)

 

Clause 6.4.10: "When intermediate checks are necessary to maintain confidence in the performance of the equipment, these checks shall be carried out according to a procedure."

Explanation:

Intermediate checks: These are checks performed on testing equipment in between its scheduled full calibrations. The aim is to find out potential equipment drift or malfunctions early on, preventing inaccurate results.

Maintaining confidence in performance: Laboratories using ISO 17025 must ensure their equipment consistently operates within acceptable accuracy and performance standards. Intermediate checks help provide this ongoing reassurance that the equipment continues to function reliably.

According to a procedure: Intermediate checks cannot be haphazard or informal. The standard requires a well-defined, documented procedure to ensure these checks are done consistently, correctly, and the results are adequately recorded for analysis.

 

Why This Clause Matters:

Reliability of Results: Regular calibration is important, but equipment performance can change between those calibrations. Intermediate checks mitigate this risk, ensuring the results generated by the equipment remain trustworthy.

Early Detection of Issues: Intermediate checks can catch minor deviations or malfunctions before they significantly affect results, preventing inaccurate data from being released.

Quality Assurance: ISO 17025 is centered on quality management. Documented procedures for intermediate checks are part of a robust quality assurance system.

Example:

A laboratory uses a precision balance for weighing samples. Full calibration occurs annually. The lab's intermediate check procedure might involve:

·        Daily checks against a standard reference weight

·        Recording the results

·        Pre-defined tolerances for acceptable deviation

·        Corrective actions if tolerances are exceeded

 

Clause 6.4.11 “When calibration and reference material data include reference values or correction factors, the laboratory shall ensure the reference values and correction factors are updated and implemented, as appropriate, to meet specified requirements."

Explanation

Calibration: The process of comparing a piece of measurement equipment against a known standard to determine its accuracy.

Reference Material: A well-characterized material with an assigned value and known uncertainty. Laboratories use these to calibrate equipment or check the validity of their methods.

Reference Values: The values assigned to reference materials (e.g., the concentration of a substance in a standard solution).

Correction Factors: Adjustments applied to measurement results from equipment to compensate for known deviations or biases.

Updated and implemented: Laboratories must actively ensure that the latest reference values and correction factors are obtained and used in their work.

Specified requirements: The needs and accuracy standards of the testing or calibration procedures.

Why this Clause Matters

Accuracy and Traceability: Outdated reference values or correction factors will lead to inaccurate results. This clause maintains the accuracy of the laboratory's measurements and ensures that the results are traceable to accepted standards.

Changes in Standards: Reference values and correction factors may evolve as standards are refined or better reference materials become available. Laboratories must keep up with these changes.

Customer Confidence: Clients and regulators rely on accurate measurements from ISO 17025 accredited labs. This clause helps uphold that trust.

Example

·        A lab calibrates a thermometer using a certified reference thermometer. The reference thermometer certificate provides updated reference values and correction factors. The lab must:

·        Update its calibration records with the new reference values.

·        Apply the correction factors to measurements made during subsequent testing.

 

Clause 6.4.12 “The laboratory shall take practicable measures to prevent unintended adjustments of equipment from invalidating results."

Explanation:

Unintended adjustments: Changes to equipment settings, configurations, or components that happen without proper controls or authorization. These could be accidental or due to tampering.

Invalidating results: Unintended adjustments can compromise the accuracy and reliability of the equipment, making the results produced by the laboratory untrustworthy.

Practicable measures: The laboratory must take reasonable and feasible steps to protect their equipment from these kinds of adjustments. What is considered "practicable" may depend on the type of equipment and the laboratory's risk assessments.

 

Why this Clause Matters:

Reliability of Results: Even small, unintended adjustments can have significant repercussions for the accuracy of the data produced by the laboratory. This clause protects the integrity of the lab's work.

Quality Assurance: ISO 17025 emphasizes a systematic approach to quality. Prevention strategies are key to this approach, and preventing unintended adjustments aligns with this.

Client Confidence: Clients rely on labs to provide accurate, reliable data. Protecting equipment from unintended adjustments upholds trust in the lab's results.

Examples of Practicable Measures:

Access Controls: Restricting who has physical access to equipment or implementing password protection for software settings.

Change Logs: Documenting any adjustments made to equipment, including the reason, date, and who carried out the adjustment.

Regular Inspections: Visually checking for signs of tampering or unauthorized changes.

Staff Training: Educating laboratory personnel about the importance of avoiding unintentional changes to equipment and how to identify potential issues.