Overview
EN ISO 11646:2014 - Leather: Measurement of area (ISO 11646:2014) specifies a standardized method for measuring the surface area of dressed and other dry flexible leathers. The method uses a mechanical pin-wheel area-measurement machine and defines requirements for apparatus, calibration, sampling and specimen conditioning. This European adoption of the ISO text is intended for use in quality control, commercial transactions and laboratory testing within the leather supply chain.
Key topics and technical requirements
- Principle: Area is determined mechanically by feeding a conditioned leather piece through a pin-wheel area-measurement machine.
- Apparatus:
- Preferred feed-roller speed: 20 m/min ± 2 m/min.
- Recommended pin-wheel pin spacing: 25,4 mm ± 2,5 mm (measured parallel to the axis).
- Use of a circular calibration template made of flexible reinforced material; template area ≥ 5% of machine capacity and width ≤ 50% of working width.
- Template verification: independent annual check traceable to national standards; acceptable if within ± 0.5% of nominal area.
- Calibration procedure: Multi-stage routine before each series of tests (warm-up passes, certified-template passes repeated N times, tolerance checks and repeat measurements) to ensure machine accuracy.
- Conditioning and sampling:
- Default conditioning atmosphere: 20 °C and 65 % RH (ISO 2419 referenced) for at least 48 h.
- Measurements should be made within 30 minutes of removing specimens from the conditioning atmosphere unless otherwise agreed and reported as a deviation.
- Support specimens to allow air access to both surfaces; note conditioning time.
- Measurement method:
- Feed the leather with the higher-friction surface against the pin-wheels, ensuring the specimen is absolutely flat and crease-free at the feed point.
- Where a straight edge exists, feed so the edge makes about a 30° angle to the direction of movement.
- Reporting: The standard requires documentation of apparatus, calibration records, conditioning regime (when deviating), number of measurements and measured area results.
Applications and users
- Leather tanneries and manufacturers for production quality control and yield reporting.
- Independent testing laboratories and R&D facilities performing standardized physical tests.
- Buyers, specifiers and trading partners requiring consistent area measurements for commercial transactions or arbitration.
- Product developers and engineers who need accurate area data to estimate material requirements and costs.
Related standards
Keywords: ISO 11646, EN ISO 11646:2014, leather area measurement, pin-wheel area-measurement machine, leather testing, calibration template, conditioning 20 °C 65 % RH.