ASTM D1003 Haze and Transmittance Scope:

When light scatters upon passing through a film or plastic-like material, it can produce an unclear or smoky effect. So, objects look hazy when viewed through the material. The factors responsible for this scattering of light are the impurities present in the plastic material, surface abrasion, and weathering of the material. This property of partial clarity in plastics is called Haze. Lower the haze measurement value, the higher the clarity of the material, indicating fewer impurities. As it can affect surface appearance quality, haze is an important property of plastic materials to consider in widely used applications like food packaging.

Test Procedure:

For the ASTM D1003 test, all plastic materials come with some degree of light scattering, which is usually measured by this test. A highly automated BYK Gardner Spectrophotometer measures the degree of transmission loss. Illuminant, observer angle and the reference color are specified before the test sample is placed into the specimen holder. The spectrophotometer then takes the reading. After taking three readings, the average of the results is calculated. Haze value is measured as the percentage of incoming light scattered by more than 2.5° through the plastic material. It has no specific unit and is expressed in percentage. 

A clear specimen is positioned some distance from the integrating sphere’s entrance port to obtain regular luminous transmittance. However, if the specimen is hazy, it must be placed at the sphere’s entrance port in order to estimate the total hemispherical luminous transmittance. Depending on the optical characteristics of the sample, the measured total hemispherical luminous transmittance will be higher than the normal luminous transmittance. In order to quantify haze and total hemispherical luminous transmittance using this ASTM D1003 test method, the specimen must be fixed to the sphere’s entrance port. Avoiding heterogeneous surface or interior faults that are not characteristic of the material will allow you to acquire haze data that is representative of the material. 

Data on haze and luminous transmittance are particularly helpful for quality assurance and specification needs. The specification of the substance being tested should be consulted before using this test procedure. The preparation, conditioning, dimensions, and testing parameters described in the materials specification—or any combination of them—shall take precedence over those in this test method. If no material specifications are provided, the default conditions are followed.

Video 01: Haze Meter and Light Transmittance