Scope:

The Diffuse Light Transmission Factor test by ASTM D1494 determines the diffuse light transmission factor of translucent reinforced plastics. The relation between the reflected light and the incident light is termed the light transmission factor of the reflection factor. This ratio is 6-8 % in a clean glass, 70-80 % in cement and concrete, 10-60% in light wood, 10-15% in a dark wood, and 5-20 % in prismatic glasses. ASTM D1494 test obtains the diffuse light transmittance factor of both corrugated and flat translucent building panels with the help of a simple apparatus. 

Test Procedure:

The test samples are conditioned at 23±2°C‌ ‌(73.4‌3±3.6°F)‌ ‌and‌ ‌50‌±5%‌ ‌relative‌ ‌humidity‌ ‌for‌‌ about 40 hours before the ASTM D1494 test is performed. The test sample is then placed in the test cabinet, completely covering the 610×610 mm (24×24 inches) inside space as specified by ASTM D1494.  The transmittance is read on the test instrument as a percentage. 

Sample size:

The translucent reinforced plastic panel test samples should be a minimum of 610 mm (24 inches) long and more than 610 mm (24 inches) wide, as per ASTM D1494. The maximum desired width is 711 mm (28 inches).

Data:

The percent transmission of the test sample.

The source and identity of test samples.

The average thickness of the test sample in inches