Comparison of different measurement methods for transmittance haze

Transmittance haze is increasingly important to the LCD and solar cell industry. Most commercial haze measurement instruments are designed according to the method recommended in the documentary standards like ASTM D 1003 (ASTM 2003 Standard Test Method for Haze and Luminous Transmittance of Transparent Plastics), JIS K 7361 (JIS 1997 Plastics-Determination of the Total Luminous Transmittance of Transparent Materials-Part I: Single Beam Instrument) and ISO 14782 (ISO 1997 Plastics-Determination of Haze of Transparent Materials). To improve the measurement accuracy of the current standards, a new apparatus was designed by the Center for Measurement Standards (Yu et al 2006 Meas. Sci. Technol. 17 N29-36). Besides the methods mentioned above, a double-beam method is used in the design of some instruments. There are discrepancies between the various methods. But no matter which method is used, a white standard is always needed. This paper compares the measurement results from different methods, presents the effect of the white standard, and analyses the measurement uncertainty.