ISO 11699-1:2008

Overview

ISO 11699-1:2008 - "Non‑destructive testing - Industrial radiographic film - Part 1: Classification of film systems for industrial radiography" defines how to classify and measure the performance of film systems used in industrial radiography (NDT). The standard specifies test methods and acceptance limits for parameters that affect radiographic image quality when films are used with specified lead screens. It is intended to ensure film-system image quality is compatible with international radiography requirements (for example ISO 5579, ISO 17636 and EN 12681). Note: this part does not apply to films used with fluorescent intensifying screens.

Key topics and technical requirements

• Scope and purpose: Classification of film systems (film + processing) used for industrial radiography to establish performance characteristics relevant to image quality.
• Test radiation and screening: Measurements are restricted to a defined radiation quality (tungsten target X‑ray tubes with specified copper filtration - equivalent to 8.00 ±0.05 mm Cu and HVL with 3.5 ±0.2 mm Cu; typical tube potential ≈ 220 kV). Film systems are evaluated with front and back lead screens of 0.02–0.04 mm.
• Measured parameters:
  • Gradient (G) - slope of the film characteristic curve at specified optical density (measured from D vs log K). Multiple exposures and polynomial fits are used; at least six measurements are required.
  • Granularity (σ) - stochastic density fluctuations measured with a microdensitometer (diffuse density, corrected to a reference density of D = 2 above fog and base). Scan length, aperture size (100 µm equivalent) and filtering/grouping procedures are specified.
  • ISO speed (S) - defined at diffuse optical density D = 2 above fog and base.
• Uncertainty and laboratory competency: Required measurement uncertainty limits (e.g., ±5% for gradient at D=2, ±7% at D=4, ±10% for granularity) and recommendation that measuring laboratories comply with ISO/IEC 17025 and participate in proficiency testing.
• Sampling and storage: Multiple batches and storage per manufacturer instructions to reflect typical product use.

Applications and users

ISO 11699-1 is used by:

• NDT laboratories and certifying bodies that classify and certify film systems for industrial radiography.
• Film and chemical manufacturers for product specification and quality claims.
• Radiography service providers and QA managers to verify image quality and select appropriate film systems for weld, casting and component inspection.
• Equipment manufacturers and procurement teams specifying film-screen combinations for compliance with NDT standards.

Related standards

• ISO 11699-2 - Control of film processing by means of reference values (process control methods).
• ISO/IEC 17025 - Competence of testing and calibration laboratories.
• ISO 5579, ISO 17636, EN 12681 - Standards referencing required radiographic image quality.

Keywords: ISO 11699-1:2008, industrial radiographic film classification, NDT film systems, film granularity, film gradient, ISO speed, radiographic image quality, lead screens, film system certification.