Overview
EN ISO 8655-6:2022 - "Piston‑operated volumetric apparatus - Part 6: Gravimetric reference measurement procedure for the determination of volume" (ISO 8655-6:2022, Corrected version 2022-06) specifies a gravimetric reference method for determining the delivered or contained volume of piston‑operated volumetric apparatus (POVA). The procedure applies to complete systems including the basic apparatus and all disposable or reusable parts used during delivery (Ex) or containment (In). This CEN‑endorsed standard replaces the 2002 edition and is intended for calibration, verification and performance testing of pipettes, burettes, dilutors, dispensers and syringes.
Key Topics
- Gravimetric measurement principle: volume determined by weighing dispensed liquid and converting mass to volume using liquid density and buoyancy (Z‑factor) corrections.
- Test equipment and liquids: requirements for analytical balances, weighing vessels, liquid reservoirs and standardized test liquids.
- Test conditions: controlled laboratory environment, evaporation management and specified test cycle timing to ensure repeatability.
- Procedures by device type: tailored test cycles and preparation for single‑channel and multi‑channel air‑displacement pipettes, positive‑displacement pipettes, burettes, dilutors, dispensers and syringes (references to ISO 8655‑2, ‑3, ‑4, ‑5 and ‑9).
- Weighing and data handling: recommended weighing procedures, evaporation correction, conversion formulas (including Z correction factor) and use of the informative annex for calculations.
- Performance evaluation: determination of mean delivered volume, systematic (bias) and random errors, and calculation/reporting of measurement uncertainty.
- Reporting: standardized result presentation to support traceability and conformity assessment.
Applications
- Laboratory metrology & calibration labs: primary method for certifying pipette and dispenser performance to ensure accurate liquid handling.
- Manufacturers of POVA: for design verification, quality control and product specifications.
- Clinical, pharmaceutical and research labs: for internal QC, routine verification and regulatory compliance where precise volumetric transfer is critical.
- Accreditation bodies and auditors: to verify calibration procedures and to assess measurement uncertainty and conformity to ISO/CEN requirements.
Related Standards
- ISO 8655 series (general requirements and device‑specific parts, e.g., ISO 8655‑2, ‑3, ‑4, ‑5, ‑9) - use in conjunction with EN ISO 8655‑6:2022 for a complete calibration framework.
Keywords: EN ISO 8655‑6:2022, gravimetric reference measurement, piston‑operated volumetric apparatus, POVA calibration, pipette calibration, volumetric accuracy, gravimetric volume determination.