Overview
EN ISO 21178:2020 - Light conveyor belts: Determination of electrical resistances specifies standardized test methods for measuring the electrical behaviour of light conveyor belts. Adopted by CEN and identical to ISO 21178:2020, this European standard defines how to determine surface resistance, volume resistance (perpendicular to the belt plane), and longitudinal and transverse volume resistance (parallel to the belt plane). It also includes methods to determine surface resistivity and volume resistivity. EN ISO 21178:2020 supersedes EN ISO 21178:2013 and is intended for laboratories, manufacturers and conformity assessment bodies working with conveyor belt components.
Key Topics and Requirements
- Scope and definitions: Terms and symbols related to electrical resistance of light conveyor belts are defined to ensure consistent testing and reporting.
- Surface resistance test methods:
- Method A - omni-directional measurement of surface resistance.
- Method B - directional measurement (longitudinal and transverse).
- Each method covers apparatus, test-piece preparation, test procedure, result expression and test reporting.
- Surface resistivity: A separate test procedure for expressing resistance as surface resistivity (ρs), including specimen preparation and measurement technique.
- Volume resistance tests:
- Perpendicular volume resistance (RD) - measurement across the belt thickness.
- Parallel volume resistance (longitudinal/transverse, RDi) - measurement along the belt plane.
- Procedures detail apparatus, specimen geometry, conditioning, measurement and reporting.
- Test documentation: The standard requires clear expression of results and standardized test reports for reproducibility and traceability.
- Normative references and conformance: The standard references ISO 21183‑1 and follows ISO/CEN collaboration procedures.
Practical Applications
- Quality control and product development: Manufacturers use the standard to verify electrical properties of light conveyor belts during material selection and production.
- Electrostatic discharge (ESD) management: Test data support ESD control strategies in industries where static can damage products or create ignition risks (e.g., electronics handling, packaging, powder handling).
- Safety and compliance: Test results help demonstrate conformity with customer specifications and workplace safety requirements.
- Material comparison: Enables objective comparison of alternative belt compounds and constructions based on electrical resistance and resistivity.
Who Should Use This Standard
- Conveyor belt and component manufacturers
- Independent testing laboratories and certification bodies
- Design and reliability engineers (materials, safety, ESD)
- Procurement and quality assurance teams in logistics, food, electronics, and light manufacturing sectors
Related Standards
Keywords: EN ISO 21178:2020, light conveyor belts, electrical resistance, surface resistance, volume resistance, surface resistivity, volume resistivity, test methods, conveyor belt testing.
