Overview
ISO 835:2007 - "Laboratory glassware - Graduated pipettes" specifies the metrological and constructional requirements for graduated pipettes intended for general laboratory use. It consolidates earlier parts and aligns pipette design with the principles in ISO 384 (volumetric glassware). The standard covers materials, dimensions, accuracy classes, delivery behaviour, graduation and marking so that users, manufacturers and calibration laboratories have a consistent basis for production, testing and use of graduated pipettes.
Key topics and requirements
- Scope & reference conditions
- Delivery volumes are adjusted using water (ISO 3696, grade 3) at a reference temperature of 20 °C (or 27 °C where adopted for tropical use).
- Accuracy classes
- Two main accuracy grades: Class A/AS (higher grade) and Class B (lower grade).
- Class AS requires a specified waiting time of 5 s; Class A and B require no waiting time.
- Pipette types
- Type 1: Partial delivery (from top zero to a graduation line).
- Type 2 & 3: Total delivery variants.
- Type 4 (blow-out): Last drop expelled by blowing; adjusted to Class B.
- Metrology & performance
- Maximum permissible errors, subdivisions and capacities are defined (see Table 1 in the standard). Limits apply at any graduation point and to differences between points.
- Delivery time and waiting time definitions and test methods are specified; delivery testing must use a glass receiving vessel to avoid capillary variations.
- Construction & materials
- Glass must meet chemical resistance and thermal requirements at least to HGB3 per ISO 719.
- Requirements for the top, suction tube, delivery jet, wall thickness and overall dimensions (see Table 2).
- Graduation & marking
- Graduation patterns I, II, III correspond to Classes A, AS, B respectively; positioning and figuring follow ISO 384.
- Required markings include unit (ml/cm3), reference temperature (20 °C or 27 °C), “Ex”, accuracy class (A/AS/B), waiting time (e.g., “Ex + 5 s” if applicable) and manufacturer ID.
Applications and users
- Useful to laboratory managers, QA/QC teams, calibration laboratories, pipette manufacturers, and procurement specialists who need reliable volumetric transfer, traceability and consistent performance.
- Applies in analytical chemistry, clinical labs, research institutions and any setting requiring accurate liquid delivery and standardized pipette production or verification.
Related standards
- ISO 384 - Principles of design and construction of volumetric glassware
- ISO 719 - Glass hydrolytic resistance (HGB classifications)
- ISO 3696 - Water for analytical laboratory use
- ISO 1769 - Pipette colour coding
- ISO 648 - One-mark pipettes (related)
- ISO 8655-2 - Piston-operated pipettes (related)
Keywords: ISO 835, graduated pipettes, laboratory glassware, pipette accuracy, delivery volume, delivery time, Class A, Class AS, Class B, pipette construction, calibration.
