Overview
ISO 11093-2:1994 - "Paper and board - Testing of cores - Part 2: Conditioning of test samples" specifies the conditioning atmospheres, apparatus and procedures for preparing cores (spool cores, paperboard cores) prior to physical testing. Based on ISO 187, this part of ISO 11093 defines how to bring test specimens to a stable moisture equilibrium so that subsequent measurements (dimensional, strength, flat crush, etc.) are repeatable and comparable.
Key topics and technical requirements
- Conditioning atmospheres: The standard defines standard atmospheres (e.g., the preferred 23 °C ±1 and 50 % RH ±2, with an alternate atmosphere around 27 °C/65 % RH as shown in the table) to be used for conditioning and testing cores.
- Climatic chamber and instrumentation: Conditioning must take place in a climatic chamber equipped with automatic control and air circulation to maintain uniform temperature and relative humidity at relevant points in the chamber. Monitoring follows procedures in ISO 187 (and ISO 554 for tolerance specifications).
- Pre-drying: To accelerate moisture equilibration, specimens may be pre-dried for 48 h in air at 40 °C ±2 °C and at 20–35 % RH before conditioning.
- Equilibrium criterion: Moisture equilibrium is reached when two consecutive weighings, at least 48 h apart, differ by no more than 0.1 % of mass.
- Specimen placement: Test pieces must be arranged to give air free access to all surfaces during conditioning.
- Conditioning report: Test records must include reference to the standard, specimen type, place/date of conditioning, number of specimens, conditioning atmosphere and duration, and any deviations from the method.
Applications and users
ISO 11093-2 is used by:
- Quality control and testing laboratories assessing paperboard and spool/core performance.
- Paper and board manufacturers and converters who need consistent test conditions for cores.
- Packaging engineers and R&D teams who evaluate core properties (dimensional stability, moisture-related behaviour) under standard atmospheres.
- Certification and compliance bodies requiring standard conditioning before mechanical or dimensional tests.
Practical benefits include improved repeatability of core tests, reduced variability from moisture differences, and consistent reporting for contractual or regulatory comparisons.
Related standards
- ISO 187:1990 - Standard atmosphere for conditioning and testing, and monitoring procedures (normative reference).
- ISO 554:1976 - Standard atmospheres for conditioning and/or testing - tolerances (referenced for tolerances).
- Other parts of ISO 11093 cover sampling, moisture content, dimensional measurements, and specific mechanical tests (Parts 3–9).
Keywords: ISO 11093-2, conditioning of test samples, paper and board cores, conditioning atmosphere, climatic chamber, moisture equilibrium, ISO 187.
