What is haze, transmittance and clarity?

What is haze, transmittance and clarity?

The appearance of a transparent or translucent product is described by total transmittance, haze and clarity. They are important parameters for plastic films, glass, food packaging, LCD panel, automotive windshields and other transparent and translucent products. Total transmittance is influenced by absorption and reflection, while Haze and clarity are interrelated which is influenced by the scattering of the diffused light.

If light scatters when it passes through a material, haze appear and compromise the clarity of the product. Transmission haze measurement is vital when the transparency is essential to ensure the clarity of a product. In order to maintain consistency of the transparency of a product, haze meter is used to measure the haze value to ensure it is within the establish reference standard. It helps to identify issue earlier for the necessary corrective actions, prevent additional cost involved due to rejected product and to ensure the quality of the product. Thus, haze can be controlled and minimized using a haze meter.

What is transmittance, haze, and clarity?

Picture 1

Transmittance / Total Transmittance

Total transmittance is the ratio of transmitted light to the incident light. Its equation is Transmittance= Tt/T1.

Tt: Transmitted light (as shown in pink color of picture 1)

T1: Incident light (as shown in the blue color of picture 1)

Haze: Wide Angle Scattering

Haze is how blurry or cloudy the appearance of a transparent material is. This measurement is defined by ASTM D1003. According to ASTM definition, haze is the percentage of light which passing through deviates from the incident beam greater than 2.5 degree on the average. Haze equation is Haze = Td/Tt.

Clarity: Narrow Angle Scattering

Clarity refers to the transparency and purity of a transparent material, as well as how well very fine details can be seen through. It is determined by percentage of light which passing through deviates from the incident beam less than 2.5 degree. Clarity equation is Tn/(Tp+Tn).

Tn: Narrow angle scattered light (as shown in yellow color of picture 1)

Tp: Transmitted parallel light (as shown in the blue color of picture 1)

Color and haze meter ZHIYI-166CH can be used to measure haze, transmittance and color parameters. If any inquiry, you are welcome to contact us.