GB/T 46828.2-2025 Plastics—Determination of the total luminous transmittance of transparent materials—Part 2:Double-beam instrument
GB/T 46828.2-2025 Plastics—Determination of the total luminous transmittance of transparent materials—Part 2:Double-beam instrument
Basic Information
Scope
This document describes a method for measuring the total transmittance of nearly colorless flat transparent plastics in the visible spectral range using a double-beam photometer under specified CIE (International Commission on Illumination) standard light sources and photoelectric detectors.
This document is applicable to transparent molded materials, films, and sheets with a thickness not exceeding 10 mm. It is not applicable to plastics containing fluorescent materials.
Note 1: The total transmittance can also be measured using a single-beam photometer in accordance with GB/T 46828.1.
Note 2: Nearly colorless plastics include plastics with very light colors.
Note 3: If the instrument can test samples with a thickness exceeding 10 mm, the results will not be comparable to those obtained for samples with a thickness less than 10 mm.