Overview
EN ISO 384:2015 - "Laboratory glass and plastics ware - Principles of design and construction of volumetric instruments" (CEN adoption of ISO 384:2015) defines fundamental principles for designing volumetric instruments made of glass or plastics to ensure reliable, convenient use to the intended degree of accuracy. The standard covers units and reference temperature, accuracy classes, calibration methods, construction features, graduation and marking, and visibility requirements.
Key topics and technical requirements
- Scope and purpose: Principles for design and construction of volumetric instruments to facilitate accurate measurement and use in laboratories. Applies to glass and plastics volumetric ware.
- Unit and reference temperature: The unit of volume is the millilitre (ml). The standard reference temperature is 20 °C (27 °C may be substituted where nationally adopted). Thermal expansion examples in the standard: a 20 → 27 °C change produces approx. 0.007% capacity change for borosilicate glass (coefficient ~9.9×10⁻⁶ °C⁻¹) and 0.02% for soda‑lime glass (coefficient ~27×10⁻⁶ °C⁻¹).
- Volumetric accuracy classes: Two accuracy grades - class A (or AS) for higher accuracy and class B for lower accuracy. Maximum permissible errors must be specified for instrument type, method of use and class. Preferred numerical series for permissible errors (and multiples) is provided (for example 10, 12, 15, 20, 25, 30, 40, 50, 60, 80).
- Calibration and use: Methods of calibration and instructions for correct use are required; ISO 4787 is cited for testing methods.
- Construction principles: Requirements for materials, wall thickness, shape, capacity, stability, delivery jets, stoppers, stopcocks and similar devices to ensure reproducible performance.
- Dimensions, graduations and marking: Guidance on linear dimensions, spacing/length/sequence of graduation lines, figuring, scale design, marking and visibility to support accurate reading and traceable calibration. Annex A relates maximum permissible error to inner diameter at the meniscus.
Applications and users
This standard is relevant to:
- Manufacturers and designers of laboratory volumetric instruments (pipettes, burettes, volumetric flasks, measuring cylinders).
- Calibration and testing laboratories specifying calibration procedures and acceptance limits.
- Laboratory managers, quality assurance personnel and procurement teams specifying equipment for analytical, clinical, pharmaceutical and research labs.
- Regulators and conformity assessors referencing harmonized European (CEN) requirements.
Related standards
- ISO 4787 - Volumetric instruments - Methods for testing capacity and for use
- ISO 383 - Interchangeable conical ground joints
- ISO/IEC Guide 99 (VIM) - Metrology vocabulary
Keywords: EN ISO 384:2015, volumetric instruments, laboratory glassware, laboratory plasticware, volumetric accuracy, calibration, reference temperature, class A, class B.