EN ISO 8655-8:2022 (ISO 8655-8:2022) specifies a photometric reference measurement procedure for determining the delivered volume of piston-operated volumetric apparatus (POVA). The procedure applies to complete systems - the basic apparatus and all selected disposable or reusable parts - with a maximum nominal volume of 5 000 µl. This standard is intended as a laboratory reference method for accurate volume verification using a spectrophotometric (photometric) technique.
Key topics and requirements
- Scope and applicability
- Reference procedure for piston-operated volumetric apparatus (pipettes, dispensers, syringes, burettes) up to 5 000 µl.
- Covers complete systems including tips and accessories involved in delivery.
- Test equipment
- Requirements for spectrophotometers, cuvettes, mixers, precision balances, density meters and pH meters.
- Reagents and solutions
- Use of defined reagents (e.g., water, buffer solutions, copper(II) chloride, Ponceau S, calibrator solutions) and guidance on stability, preservatives and light sensitivity.
- Test conditions
- Environmental conditions (test room, evaporation control) and procedural controls to ensure repeatability.
- Procedure
- Steps for system calibration, photometric measurement, cuvette preparation, dispensing of test liquids and calculation of delivered volume.
- Specific sections for device types: single-channel and multi-channel air displacement pipettes, positive displacement pipettes, burettes, dispensers and syringes.
- Evaluation and reporting
- Calculation of calibration constant, test liquid volume, temperature correction, mean volume, systematic and random errors, and measurement uncertainty.
- Requirements for recording and reporting results.
Practical applications and users
- Calibration and testing laboratories use ISO 8655-8 as a reference method for high-accuracy volume verification and to establish traceability.
- Manufacturers of pipettes and piston-operated devices apply the standard for performance validation and product development.
- Quality assurance personnel and laboratory managers use the procedure to qualify equipment and document compliance with internal or regulatory quality systems.
- Accreditation bodies and metrology labs reference the method when assessing uncertainty and measurement performance.
Related standards
Keywords: ISO 8655-8, EN ISO 8655-8:2022, photometric reference measurement, piston-operated volumetric apparatus, pipette calibration, spectrophotometric volume determination, measurement uncertainty.
