This part of ISO 8655 specifies metrological requirements, maximum permissible errors, requirements for marking and information to be provided for users, for air-displacement (type A) and positive displacement (type D) single-channel and multi-channel pipettes, complete with their selected tip(s) and any other essential, consumable parts, designed to deliver the selected volume (Ex). NOTE General requirements and definitions of terms for piston-operated volumetric apparatus are given in ISO 8655-1. The gravimetric reference measurement procedure for the determination of volume is given in ISO 8655-6. The photometric reference measurement procedure for the determination of volume is given in ISO 8655-8. Alternative methods for the determination of volume are described in ISO 8655-7. For safety requirements of electrically powered pipettes, see regional or national safety standards.