ISO 8655-2:2022

Overview

ISO 8655-2:2022 - "Piston-operated volumetric apparatus - Part 2: Pipettes" - is the international standard that defines metrological and usability requirements for single- and multi-channel pipettes. It covers air-displacement (Type A) and positive-displacement (Type D) pipettes, including fixed- and variable-volume models, together with their selected tips and essential consumables. The document specifies requirements for metrological performance, maximum permissible errors, marking, and user information to support correct operation, calibration and quality control.

Key Topics

• Scope and types: Defines fixed-volume and variable-volume pipettes; distinguishes Type A (air-displacement) from Type D (positive/direct displacement) and subtypes D1 (reusable elements) and D2 (disposable elements).
• Metrological requirements: Sets performance criteria and maximum permissible errors for different pipette types, single- and multi-channel instruments, and pipette tips; includes tables (revised Tables 1–3) and rules for calculating permissible errors for intermediate volumes.
• Adjustment procedures: Requirements for initial adjustment at a reference temperature (20 °C or 27 °C options), provisions for subsequent adjustment, and clear marking when adjustment has been modified. Guidance for adjusting for liquids with properties different from water is included.
• Design and ergonomics: Requirements to minimize transfer of hand warmth, consistent piston operation, and tip sealing to reduce systematic drift and variability.
• Pipette tips: Shape, sealing, wettability and sterilization effects are addressed to ensure consistent dispensing and metrological integrity. Disposable versus sterilizable tip requirements are covered.
• User information and marking: Mandatory information manufacturers must provide (operation, adjustment, special liquid handling) and labeling of pipettes and tips.
• Informative annexes: Annex A lists possible sources of error for air-displacement pipettes; Annex B covers motorised/electronic pipettes and multi-dispensing test methods.

Applications and Who Uses It

ISO 8655-2:2022 is used by:

• Manufacturers for product design, factory adjustment and declarations of conformity.
• Calibration laboratories and test houses for independent verification, gravimetric/photometric or alternative volume measurement procedures (see ISO 8655-6, -7, -8).
• Clinical, pharmaceutical and R&D labs for procurement specifications, routine checks, validation and traceable calibration of pipettes (single- and multi-channel).
• Quality and compliance teams ensuring instruments meet metrological requirements and labeling/ documentation standards.

Related Standards

• ISO 8655-1 (Terminology, general requirements and user recommendations)
• ISO 8655-6 (Gravimetric reference measurement procedure)
• ISO 8655-7 (Alternative measurement procedures)
• ISO 8655-8 (Photometric reference measurement procedure)
• ISO 3696 (Water for analytical laboratory use)

Keywords: ISO 8655-2:2022, pipettes, air-displacement pipette, positive displacement pipette, metrological requirements, maximum permissible errors, pipette calibration, lab equipment, multi-channel pipettes.