Measurement and analysis of haze and clarity guarantee a uniform and consistent product quality and help analyze influencing process parameters and material properties, e.g.cooling rate or compatibility of raw materials.
The figure on the picture shows the measurement principle of the haze meter:
A light beam strikes the specimen and enters an integrating sphere. The sphere's interior surface is coated uniformly with a matte white material to allow diffusion. A detector in the sphere measures total transmittance and transmission haze. A ring sensor mounted at the exit port of the sphere detects narrow angle scattered light ( clarity).
The measurement of Total Transmittance and Transmission Haze is described in international standards. Two different test methods are specified:
1. IS013468 Compensation method
2. ASTM D1003 Non-compensation method
The compensation method takes the light reflected on the sample surface into account. Differences between the two methods can be approximately 2 Total Transmittance on clear, glossy samples.
ASTM D 1003
Measurement conditions are different during calibration and actual measurement. During calibration, part of the light escapes through the open entrance port of the haze meter. While taking a measurement, the entrance port is covered with the sample, thus, the amount of light in the sphere is increased by the light reflected at the sample surface.
Measurement conditions are kept equal during calibration and measurement due to an additional opening in the sphere. During calibration the sample is placed at the compensation port. For the actual measurement, the sample is changed to the entrance port. Thus, the so-called sphere efficiency is independent of the reflection properties of the sample.
Two Standard Methods in one Unit
The clarity and haze meter CS-720 complies with both ASTM and ISO measurement standards. It can meet the following measurement standards ASTM D1003 / D1044, ISO13468 / ISO14782, JIS K7105, JIS K7361, JIS K7163 and other international standards. If any inquiry, you are welcome to contact us.