Tests luminous transmittance

Tables 4—6 Ust ASTM methods used for the characterization of PB and PMP. A number of specialized methods were developed for testing particular articles manufactured from polyolefins several of these determine the performance of PB and PMP film, including the measurement of the film s dart impact strength and tear strength. Dart impact strength is measured by dropping a heavy dart with a round tip on a stretched film. Tear resistance, which reflects the film s resistance to tear propagation, is measured with the Ehnendorf tear tester. Two values for the tear strength are usually reported, one in the machine dkection of the film and the other in the transverse dkection. Pipes manufactured from PB are tested by pressurizing them internally with water the time-to-burst failure is determined at various temperatures (46). The standard test method for haze and luminous transmittance (ASTM D1003) is used for the measurement of PMP optical characteristics.

Opacity or transparency is important when the amount of light to be transmitted is a consideration. These properties are usually measured as haze and luminous transmittance. As reviewed haze is defined as the percentage of transmitted light through a test specimen that is scattered more than 2.5° from the incident beam. Luminous transmittance is the ratio of transmitted light to incident light. Table 5-7 provides the optical and various other properties of different transparent plastics. 

ASTM D1003-92, "Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics," Philadelphia (1992). 

A related property is haze or the scattering of light as it passes through a transparent material. The standard test method for measuring both transmittance andhaze is ASTM D1003-00, Standard Test Methodfor Haze and Luminous Transmittance of Transparent Plastics Instruments that... 

Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics). The film samples were cut into a rectangular piece (1x2.5 cm), fixed on the inner side of a 1cm of spectrophotometer cell and the absorbance spectrum recorded. The film opacity measurements were repeated three times. 

Haze n. Haze and luminous transmittance are tests to measure the fight transmittancy of different types and grades of plastic materials Haze is defined in ASTM D 1003 as the percentage of transmitted fight passing through the specimen which deviates more than 2.5° from the incident beam by... 

Light transmittance (luminous transmittance, light transmissivity). The ability of a material to pass incident hght through it, whether specular or diffuse. ASTM (www.astm.org) prescribes several tests of this property in plastics. Transmissivity is... 

Standard test method for haze and luminous transmittance of transparent plastics, ASTM Standard, Book of Standards, Vol. 08.01 ASTM D1003-07el, ASTM International, West Conshohocken, PA, 2009. 

Light absorbance (absorbance, absorptivity). The percentage of the total luminous flux incident upon a test specimen that is neither reflected from, nor transmitted through the specimen. Compare light reflectance and light transmittance. 

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