Overview
EN ISO 835:2007 sets out the international standard requirements for graduated pipettes made of glass for laboratory use. Published by CEN and identical to ISO 835:2007, this standard specifies the metrological and constructional features necessary for graduated pipettes used in a variety of laboratory settings. EN ISO 835:2007 ensures that graduated pipettes meet consistent quality, reliability, and accuracy required for scientific, analytical, and quality control processes across laboratories worldwide.
Key Topics
Metrological and Constructional Requirements
- Specifies accuracy classes (A, AS, and B) for pipettes, addressing higher and general-use laboratory precision.
- Defines requirements for material quality; glass used must meet chemical and thermal resistance specifications.
- Details the permitted division markings and graduation patterns for easy and accurate volume reading.
Types of Graduated Pipettes
- Describes four types:
- Type 1: Partial delivery
- Type 2 & 3: Total delivery
- Type 4: Total delivery with blow-out for complete evacuation of liquid
Accuracy and Error Limits
- Sets maximum permissible errors in delivered volumes by class and nominal capacity, supporting precise volume delivery.
- Stipulates delivery and waiting times, particularly for Class AS pipettes requiring a 5-second waiting period to enhance delivery accuracy.
Graduation, Marking, and Visibility
- Outlines strict requirements for the clarity and permanence of graduation lines and inscriptions, advocating practices for clear, durable labeling.
- Specifies mandatory markings such as unit of volume, reference temperature, adjustment method, class of accuracy, and manufacturer identification.
- Incorporates color coding guidance compliant with ISO 1769 for quick identification and classification.
Applications
Laboratory Usage
- Widely applied in chemical, clinical, pharmaceutical, and research laboratories for the accurate measurement and transfer of liquid volumes.
- Ensures reliable and repeatable results in titration, preparation of standards, sample dilutions, and analytical testing.
- Supports both routine and high-precision laboratory workflows, with choices between Classes A/AS for high-accuracy tasks and Class B for general applications.
Quality Assurance
- Facilitate compliance with international requirements in quality management systems for laboratory glassware.
- Essential for laboratories seeking accreditation or certification to recognized standards, providing documented assurance of equipment accuracy.
Educational and Training Contexts
- Frequently utilized in academic laboratories for scientific instruction in basic and advanced laboratory techniques.
Related Standards
- ISO 384: Principles of design and construction for volumetric glassware - core reference for this standard's construction requirements.
- ISO 648: One-mark pipettes - provides requirements for single-volume pipettes.
- ISO 1769: Colour coding of laboratory glassware - referenced for classification color codes.
- ISO 3696: Specifications for water used in analytical laboratories.
- ISO 4794: Methods to assess chemical resistance of color markings.
- ISO 8655-2: Piston-operated pipettes - alternative for mechanical liquid handling.
Practical Value
Adopting laboratory glassware that complies with EN ISO 835:2007 ensures trustworthy, harmonized performance in volume measurement. Laboratories benefit from using standardized graduated pipettes to:
- Minimize risk of measurement error
- Demonstrate compliance during audits and inspections
- Streamline procurement by referencing a recognized standard
- Enhance data validity and comparability in global scientific collaboration
For laboratories aiming to maintain high-quality processes, EN ISO 835:2007 is an essential standard for selecting and verifying graduated pipettes.