Haze and Light Transmittance Test

Haze is a cloudy cloud-like appearance due to the diffusion effect of light. It is usually expressed as a percentage of the ratio of the diffusely reflected luminous flux to the luminous flux transmitted through the material. It is one of the important parameters to indicate the transparency of the material. The light transmittance is the percentage of the luminous flux passing through the sample to the luminous flux incident on the sample. There is no specific unit for haze, and it can also be said that its unit is a percentage. Generally, the haze value is expressed directly by a percentage. The greater the haze, the stronger the ability to scatter light.

Sample Requirements

The sample must be transparent or translucent.
Note that the sample is required to be non-toxic and harmless, and no qualitative change will occur in the air.
Block size requirements: the diameter or side length is more than 2 cm.
The liquid should not be less than 25 mL.

Application

For testing the light transmittance and haze of all transparent and translucent parallel plane samples (plastic plates, sheets, etc.)
For turbidity or clarity determination of liquid samples (water, beverages, etc.)

Instrument and Result Display

FAQ

Q1. Calculation formula of haze and transmittance.

A. In the process of measuring the haze and light transmittance of the sample, it is necessary to measure the incident light flux (T1), the transmitted light flux (T2), the scattered light flux of the instrument (T3), and the scattered light flux of the sample (T4). Its calculation formula is as follows.

Light transmittance: Tt=T2 / T1×100%, where T1 is set to 100

Haze: H=T4 / Tt×100%, T3 is 0

Q2. In which wavelength range are the haze and light transmittance measured?

A. Measured in the wavelength range of visible light (390 nm - 780 nm).