Overview
ISO 648:2008 - "Laboratory glassware - Single-volume pipettes" specifies the metrological and constructional requirements for volumetric (single-volume) pipettes with one mark (total delivery) and two marks. The standard defines how pipettes must be designed, manufactured, adjusted and marked so they deliver their nominal volume reliably at a reference temperature (20 °C, or 27 °C for tropical use). ISO 648 aligns with the general principles in ISO 384 for volumetric glassware.
Key topics and technical requirements
- Scope and types
- Applies to single-volume pipettes with one or two graduation marks, suitable for general laboratory use.
- Two accuracy types: no waiting time (Classes A and B) and 5 s waiting time (Class AS).
- Accuracy classes and errors
- Classes: A, AS (higher grade) and B (lower grade).
- Maximum permissible errors are specified by nominal volume (e.g., 10 ml Class A ±0.02 ml; 1 ml Class A ±0.008 ml).
- Delivery time and waiting time
- Delivery time ranges are given per nominal volume and class (see Table 5 in the standard).
- Class AS requires a 5 s waiting time, and this must be marked on the pipette.
- Construction and materials
- Made from glass meeting chemical resistance and thermal properties at least to HGB3 (ISO 719).
- Shapes: straight tube or bulb pattern; dimensional limits and wall thicknesses are specified.
- Delivery jet design (smooth taper or capillary) to avoid turbulent outflow.
- Graduation and meniscus
- Graduation line(s) must be permanent, uniform, encircle the tube (small gap allowed), and meet thickness limits.
- Meniscus setting follows procedures in ISO 384.
- Marking and visibility
- Each pipette must be marked with nominal volume (ml/cm3), reference temperature, “Ex”, accuracy class (A/AS/B), waiting time when applicable, and manufacturer’s mark. Certification and delivery time markings are addressed.
Applications and users
- Practical use:
- Ensures accurate volumetric delivery for analytical chemistry, pharmaceutical QC, environmental testing, academic laboratories, and routine lab work.
- Useful for procurement specifications, manufacturing tolerances, calibration, certification, and compliance testing.
- Primary users:
- Laboratory managers, QA/QC personnel, metrology labs, pipette manufacturers, instrument calibrators, and regulatory bodies.
Related standards
- ISO 384 - Principles of design and construction of volumetric glassware
- ISO 3696 - Water for analytical laboratory use
- ISO 719 - Glass hydrolytic resistance classification
- ISO 1769 - Pipette colour coding
- See also: ISO 835 (graduated pipettes) and ISO 8655-2 (piston-operated pipettes)
Keywords: ISO 648, single-volume pipettes, volumetric pipettes, laboratory glassware, Class A, Class AS, Class B, maximum permissible error, delivery time, ISO 384.
