EN ISO 8655-5:2022 PDF

Overview

EN ISO 8655-5:2022 / ISO 8655-5:2022 specifies metrological and user requirements for piston-operated volumetric apparatus - dispensers. It applies to dispensers with nominal volumes from 1 µl to 200 ml, designed to deliver their preset volume (Ex). The standard is part of the ISO 8655 series adopted by CEN and supersedes the 2002 edition.

Keywords: piston-operated volumetric apparatus, dispensers standard, ISO 8655-5, volumetric accuracy, laboratory dispenser calibration.

Key topics and technical requirements

• Scope of requirements
  • Metrological requirements and maximum permissible errors for dispensers.
  • Marking and user information that manufacturers must provide.
• Device types and operation
  • Single-stroke and multiple-delivery (ratchet) dispensers.
  • Drive mechanisms: manual, electric, pneumatic or hydraulic.
  • Change-over units (interchangeable pistons/cylinders) and importance of including them in performance assessment.
• Adjustment
  • Dispensers must have an initial adjustment at manufacture.
  • Subsequent adjustment allowed per manufacturer instructions; any adjustment must be recorded and visibly indicated.
  • Reference environmental conditions: standard reference temperature either 20 °C or 27 °C, relative humidity 50%, barometric pressure 101.3 kPa, using ISO 3696 grade 3 water.
• Metrological performance
  • Total-system testing must include drive, change-over unit, aspiration and delivery tubing.
  • Determination of systematic (trueness) and random (precision) errors using reference methods.
  • Reference measurement procedures: gravimetric (ISO 8655-6), photometric (ISO 8655-8), or alternative methods (ISO 8655-7).
  • Dispenser tips and tubing: specific metrological requirements and manufacturer guidance on compatible tubing to meet specifications.
• Documentation & marking
  • Manufacturers must supply clear marking and user information (operation, adjustment, calibration instructions, compatibility of change-over units and tips).

Applications and who uses this standard

• Manufacturers - design, quality control, and conformity claims for laboratory dispensers.
• Calibration laboratories and test houses - procedures and acceptance criteria for calibration and verification.
• Laboratory users - selection, correct operation, maintenance, and routine checks to ensure volumetric accuracy in analytical workflows (pharmaceutical, clinical, research, environmental testing).
• Regulatory and procurement teams - specification of equipment that meets defined metrological performance.

Related standards

• ISO 8655-1 - Terminology, general requirements and user recommendations
• ISO 8655-6 - Gravimetric reference measurement procedure
• ISO 8655-7 - Alternative measurement procedures
• ISO 8655-8 - Photometric reference measurement procedure
• ISO 3696 - Water for analytical laboratory use

EN ISO 8655-5:2022 helps ensure dispenser accuracy, repeatability and traceability - essential for reliable volumetric delivery in laboratory settings.