ISO/IEC 17025 clause 6.4: manage equipment from selection to release
Clause 6.4 covers more than instruments. Equipment can include software, measurement standards, reference materials, reference data, reagents, consumables and auxiliary apparatus needed for correct laboratory work. The laboratory must have appropriate access and control, whether or not it owns the item permanently.
What clause 6.4 requires in practice
Clause 6.4 has thirteen provisions that follow equipment through its working life. The laboratory has access to the equipment it needs, and the definition is wide. It takes in measuring instruments and software, and also standards, reference materials and data, reagents, consumables and supporting apparatus. Equipment outside permanent control is covered by the same requirements.
A procedure covers how items are handled, moved, stored, used and maintained on a plan. Equipment is verified against specified requirements before entering or returning to service and must be able to deliver the needed accuracy or uncertainty. Calibration is required in defined circumstances, a calibration programme is kept under review, and status is visible to users. Doubtful equipment is taken out of service and nonconforming work is evaluated. Intermediate checks follow a procedure, correction factors are kept current, unintended adjustment is prevented and records are kept.
The output is equipment that is demonstrably suitable, identified, controlled and traceable through its history.
Establish suitability before use
Clauses 6.4.1 and 6.4.2 address access to necessary equipment and equipment outside permanent control. Clause 6.4.3 requires a procedure covering handling, transport, storage, use and planned maintenance. These arrangements should prevent deterioration, contamination or damage that could affect performance.
Under clause 6.4.4, verify conformity with specified requirements before placing equipment into service or returning it to service. Clause 6.4.5 requires measurement equipment capable of the accuracy or uncertainty needed for valid results. Acceptance therefore needs a technical basis: a purchase order, successful power-on test or supplier's delivery note is not enough by itself.
Distinguish calibration and other checks
Clause 6.4.6 identifies when measuring equipment needs calibration: where accuracy or uncertainty affects reported-result validity, or calibration is necessary for traceability. Clause 6.4.7 requires a calibration programme reviewed and adjusted as necessary. Clause 6.4.8 requires users to be able to recognise calibration status or a defined validity period through labelling, coding or another appropriate identification method.
An intermediate check under clause 6.4.10 helps maintain confidence between calibrations where needed and must follow a procedure. It is not automatically a substitute for calibration. Maintenance, verification, calibration and intermediate checks answer different questions, even when performed during one service visit.
Use correction information and prevent unintended changes
Where calibration or reference-material information includes reference values or correction factors, clause 6.4.11 requires them to be kept current and applied as appropriate. Follow the information into calculations and software; filing the certificate without implementing a needed correction can leave the reported result wrong.
Clause 6.4.12 requires practical measures against unintended adjustments that invalidate results. Controls might include restricted settings, seals or access permissions suited to the equipment. The standard does not prescribe one physical locking method for every instrument.
Respond when equipment becomes doubtful
Clause 6.4.9 addresses overload, mishandling, questionable results, defects and departure from specified requirements. Take affected equipment out of service, prevent inadvertent use, evaluate the effect on work and initiate the nonconforming-work process. Repair alone does not resolve the question of results already produced.
Confirm correct performance before return to service. Consider whether calibration, verification, updated correction factors or other technical checks are needed following the event. The decision should fit the defect and intended use rather than depend only on a service provider's statement that the instrument now operates.
Retain records that explain the equipment history
Clause 6.4.13 requires records for equipment that can influence laboratory activities. Relevant information includes identity and software or firmware version, manufacturer and unique identification, suitability evidence, location, calibration and acceptance information, reference-material validity, maintenance and relevant damage or modifications. Apply the items where relevant rather than forcing irrelevant fields onto every consumable.
An equipment register can organise this information, but a register listing serial numbers and next dates alone is incomplete. The records need to support decisions about suitability, status and past performance. Link supporting certificates and checks so the technical reviewer can follow the history.
Why equipment control matters to the business
Equipment is where measurement quality either begins or quietly fails. A balance that has drifted, a software update that altered a calculation or a reagent past its useful life can produce results that look normal and are wrong.
A well-run equipment system protects the laboratory financially. It prevents unnecessary calibration spending, shortens investigations when something goes wrong and limits the number of customer reports that must be reconsidered after a failure. It also gives assessors and customers an easy way to see that the laboratory knows the condition and history of the tools behind its results.
How to implement clause 6.4
Choose one family of equipment and trace it from selection to disposal. The same exercise then extends to the rest.
- Define what counts as equipment for your methods, including software, reagents and reference materials, not only instruments.
- Set acceptance criteria before purchase or loan, based on the accuracy or uncertainty the work requires.
- Verify performance before first use and after every repair, loan or relocation.
- Decide calibration need from the effect on results, set the programme and make status visible at the point of use.
- Write the procedure for handling, transport, storage and maintenance, and add intermediate checks where confidence between calibrations needs support.
- Keep records that explain each item's history, including software version, location, calibration, maintenance and damage.
- Check that correction factors from certificates reach the calculations and that settings cannot be altered unintentionally.
- Review the whole system from time to time, looking at failures, overdue items and near misses, and change the procedure where the same weakness repeats.
Evidence an assessor expects for clause 6.4
Assessors expect to follow an item of equipment from record to bench and back.
- Equipment records that agree with the item in front of them, including identity, version and status.
- Calibration results with a documented review against requirements, and correction factors that appear in calculations.
- Evidence of verification before use or return to service.
- Records of out-of-service events, with the evaluation of affected work.
- Observation of staff, who should be able to explain how they know the item is fit for use.
Two illustrative equipment decisions
A calibration laboratory receives a borrowed reference instrument. It verifies suitability for the required range and uncertainty, checks calibration and handling history, and applies the same relevant controls as for its own equipment. Ownership by a trusted partner is not a technical acceptance criterion.
A testing laboratory updates instrument software. It records the version, evaluates affected calculations and verifies performance before use. If new reference values need to be applied, the laboratory checks that the reporting workflow uses them rather than retaining an obsolete factor in a spreadsheet.
Common mistakes
Avoid treating calibration stickers as the whole control system, calibrating every item without assessing need, extending intervals only to save cost, or returning repaired equipment without verification. Also avoid ignoring reagents, reference materials and software because they do not resemble conventional instruments. Their influence on results determines the relevant control.
Explore each numbered part
6.4.6 · decide when calibration is required
Decide which measuring equipment needs calibration by examining its effect on reported-result validity and metrological traceability. This guide distinguishes direct measurements, correction inputs and calculated results, and explains why a calibration decision should reflect the method's needs rather than a blanket rule to calibrate every asset annually.
6.4.7 · plan and review calibration intervals
Build a calibration programme that maintains confidence in equipment status as use and performance change. This guide explains interval decisions, review triggers and the relationship with intermediate checks, using laboratory examples to show why a fixed annual date or an automatic extension is not a sufficient technical rationale.
6.4.9 · control faulty or questionable equipment
Respond when equipment is damaged, overloaded, defective, outside requirements or producing doubtful results. This guide explains removal from service, prevention of unintended use, evaluation of earlier work and verification before return. Examples show why repair and recalibration do not by themselves close the question of affected customer results.
Frequently asked questions
Does all laboratory equipment require calibration?
No. Clause 6.4.6 establishes the triggers for measuring equipment. Other items still require suitable controls, but calibration is not automatically appropriate for every item.
Can we use rented or borrowed equipment?
Yes, provided the applicable equipment requirements are met. Temporary access does not remove the need to establish suitability, status and effective control.
Is an intermediate check equivalent to calibration?
Not necessarily. Intermediate checks maintain confidence between calibrations where needed. Their purpose and technical basis differ from establishing calibration results and traceability.
Turn this requirement into reliable laboratory practice
Ask Sterling to review an equipment family from selection through reporting, including calibration evidence and failure response. A free consultation can identify where the agreed consulting and documentation work should strengthen technical decisions, records and staff understanding.
Build the team's understanding through Measurement Uncertainty (ISO/IEC 17025:2017). Discuss the relevant scope, employee learning and agreed access to Effivity ISO & GRC automation software with Sterling; laboratory technical decisions remain with competent, authorised personnel.
ISO/IEC 17025 requirements hub · Resource requirements · When calibration is required · Plan calibration intervals · Control unreliable equipment · Metrological traceability