ISO 9370:2017

Overview

ISO 9370:2017 - Plastics - Instrumental determination of radiant exposure in weathering tests - General guidance and basic test method - provides standardized methods for measuring irradiance on a planar surface and for integrating those measurements to determine radiant exposure. The standard covers measurements of natural solar radiation, intensified natural sunlight (e.g., solar-concentrating exposures), and radiation from laboratory light sources used in natural weathering, accelerated natural weathering, artificial accelerated weathering, and artificial accelerated irradiation tests. ISO 9370:2017 focuses on instrumental radiometric techniques (radiometers and spectroradiometers) and does not specify procedures using blue‑wool standards, chemical actinometry, or polymer/film dosimetry.

Key topics and technical requirements

• Measurement types: Continuous measurement and integration of total solar, solar ultraviolet (UV), and spectral solar (ultraviolet) irradiance to provide accumulated radiant exposure.
• Instrument guidance: Recommended characteristics for non‑selective and selective (UV) radiometers, detectors, cosine receptors, recorders and data loggers (see Clauses 5–5.4).
• Calibration: Procedures and requirements for calibrating reference and field radiometers, including selective UV radiometers (Clause 6). The 2017 revision clarifies calibration of selective instruments and addresses spectral mismatch issues (Annex B).
• Procedure: Test procedures for fixed‑angle or equatorial‑mount natural exposures, Fresnel‑reflecting concentrator systems for accelerated natural weathering, and laboratory sources for artificial accelerated irradiation (Clause 7).
• Reporting: Required elements for an exposure report that accompany weathering test results (Clause 8).
• Terminology and definitions: Key radiometric terms (irradiance, spectral irradiance, direct/diffuse radiation, FWHM, cut‑on/cut‑off wavelengths) are defined to ensure consistency.

Practical applications and users

ISO 9370:2017 is used to ensure reliable and comparable measurement of light exposure in weathering tests, with practical benefits including:

• Comparing outdoor exposures at different times/locations using radiant exposure rather than time alone.
• Monitoring and controlling UV dose in accelerated weathering devices and laboratory irradiation chambers.
• Selecting, calibrating and validating radiometers for test laboratories, quality control, R&D and durability testing.

Typical users:

• Plastics manufacturers and formulators
• Independent testing laboratories and certification bodies
• Materials scientists and product developers assessing UV/solar durability
• OEMs and procurement teams specifying weathering test conditions

Related standards

ISO 9370:2017 references calibration and instrument standards such as ISO 9059, ISO 9060, ISO 9846, ISO 9847, and relevant ASTM practices (e.g., ASTM G90, G130, G183). Consult these for detailed calibration procedures and instrument classification.

Keywords: ISO 9370:2017, radiant exposure, weathering tests, radiometer, solar irradiance, UV radiometers, accelerated weathering, calibration, spectral irradiance.