ISO 15106-2:2003

Overview

ISO 15106-2:2003 specifies an instrumental method for measuring the water vapour transmission rate (WVTR) of plastic film, sheeting and multi-layer structures using an infrared detection sensor. The method uses a two-chamber transmission cell (a wet, high‑humidity chamber and a dry chamber) separated by the specimen. An infrared humidity sensor monitors the change in humidity in the dry chamber until a steady state is reached and the result is converted to WVTR (expressed in g/(m²⋅24 h)). The method is designed for rapid measurement across a wide range of water vapour transmission rates.

Key topics and requirements

• Principle: Dry chamber (controlled RH) is separated from saturated/humid chamber by the specimen; transmitted water vapour is detected by an infrared sensor.
• Apparatus: Transmission cell, IR humidity sensor, pump, flow meter (5–100 ml/min), drying tube, valves and temperature controller (±0.5 °C). Transmission area typically 5–100 cm².
• Sensor performance: IR sensor sensitivity down to ~1 µg/litre (≈1 ppm by volume); follow manufacturer calibration and maintenance.
• Specimens & conditioning:
  • Representative, wrinkle‑free specimens; hermetically mounted.
  • Usually three specimens (more may be used for better representation).
  • Condition specimens at 23 °C ± 2 °C and 50 % RH ± 10 % (or as specified).
• Test conditions: Preferred options include combinations of temperature (23–40 °C) and high RH (75–90 %). Exact set chosen by agreement.
• Procedure & calculation:
  • Zero-level voltage measured with dried air.
  • Test and reference specimens measured to steady state (output voltage stable within ±5 %).
  • WVTR calculated by comparing sensor voltages for test and reference specimens, scaled by reference WVTR and transmission areas.
• Reporting: Test report shall reference ISO 15106-2 and include test conditions, reference specimen details, sample identification, specimen side facing vapour, area, thickness, conditioning, number of specimens, test result, date, and any deviations (e.g., steady state not within ±5 %).
• Precision: Not stated - no inter-laboratory precision data available in this edition.

Applications and users

• Used by manufacturers and R&D of plastic films and barrier packaging (food, pharmaceutical, medical devices) to assess moisture barrier performance.
• Employed by quality-control and testing laboratories for product specification, incoming inspection and shelf‑life evaluation.
• Relevant for manufacturers of multi‑layer and laminated films, converters, and packaging designers optimizing moisture-sensitive products and processes.
• Useful where rapid, instrumental WVTR measurement with good sensitivity is needed (alternative to gravimetric methods).

Related standards

• ISO 15106-1: Humidity detection sensor method (same series)
• ISO 15106-3: Electrolytic detection sensor method
• ISO 2528:1995: Gravimetric (dish) WVTR method - for reference specimen calibration
• ISO 4593:1993: Thickness measurement for films and sheeting

Keywords: ISO 15106-2, water vapour transmission rate, WVTR, infrared detection sensor, plastics film, barrier properties, test method.