90% of people get it mixed up! Haze and light transmittance are simply not the same thing!

Friends in purchasing and quality control must have heard this: "My material has a light transmittance of 90%+, it's definitely clear enough!" Many people also assume a logic: the higher the light transmittance, the more transparent the material and the less foggy it is. But reality hits hard—two plastic films with almost identical measured light transmittance can look completely different; one is crystal clear, while the other always looks like it's covered in a layer of mist. Why is this?

The answer is simple: you have completely confused haze and light transmittance, two entirely independent indicators! This is also the #1 trap that 90% of people fall into during haze measurement. 

Let’s first give a plain-language definition of these two indicators, and you’ll never mix them up again.

First, let's talk about light transmittance. It only looks at the "quantity," not the "direction." To put it bluntly, it’s about how much light successfully "gets through" when it passes through a material. It’s like pouring water into a sieve; the ratio of the water that eventually flows out to the total amount of water is the light transmittance. Whether the water flows straight down through the holes or splashes everywhere and flows out at an angle, as long as it comes out, it counts toward light transmittance.

Haze, on the other hand, only looks at "quality," not "total volume." It measures how much of the light that passed through is "off-track" scattered light. Using the water pouring example again, light transmittance looks at how much total water flows out, while haze looks at how much of the outflowing water splashed everywhere instead of falling straight through the holes.

Let’s give you an extreme example: frosted glass. Its light transmittance is actually not low at all—many types of frosted glass can reach over 80%—but its haze is close to 100%. This is because almost all light is scattered in all directions by the rough surface as it passes through, so you can only see brightness but cannot see the objects on the other side clearly at all. In contrast, high-end optical glass has a light transmittance of 92% but a haze as low as 0.1%. Almost all light passes through straight, so everything can be seen clearly.

Here is the key point: haze and light transmittance are two completely independent indicators with no absolute positive correlation. It is not true that the higher the light transmittance, the lower the haze must be.

 For example, a film with 90% light transmittance might contain many microscopic impurities invisible to the naked eye, leading to significant scattered light and a haze as high as 5%, making it look foggy and whitish. Another film might have only 88% light transmittance but extremely high material purity and a uniform structure, resulting in a haze of only 0.3%, making it look clearer and more transparent.

In daily quality inspection, incoming material acceptance, and product R&D, a professional and reliable testing instrument is essential to accurately control both light transmittance and haze. The CHNSpec TH-110 Haze Meter is specifically designed for industries such as film, glass, plastic, packaging materials, and optical plates, providing a one-stop solution for precise haze and light transmittance testing.

Core Advantages & Key Parameters of CHNSpec TH-110 Haze Meter:

1.Dual Measurement, High Efficiency: Simultaneously measures light transmittance and haze. Data is displayed in real-time, eliminating blind spots from single-parameter testing. It is suitable for material comparison, sampling inspection, and finished product control.

2.Precise Detection Compliant with Standards: Strictly follows domestic and international standards such as GB/T 2410 and ASTM D1003. It features a parallel light path design and diffuse reflectance reception with a stable, uniform light source to avoid scattered light detection errors, accurately capturing even tiny haze differences.

3.High Precision and Good Repeatability: Measurement range for haze/transmittance is 0-100%. Haze resolution is 0.01 units; repeatability within 0.05 for a Φ21mm aperture. Transmittance resolution is 0.01 units; repeatability ≤0.1 units. Integrating sphere Φ154mm, light path structure 0/D (parallel light illumination, diffuse reflectance reception).

4.Versatile Adaptation and Simple Operation: Equipped with 21mm / 7mm dual measurement apertures and an open measurement area, it is compatible with films, sheets, and small irregular samples. Smart touch screen operation allows for one-key testing, automatic data storage, and supports data export and report printing, facilitating batch data traceability.

5.Stable, Durable, and Suitable for Mass Production QC: The machine structure is stable and resistant to ambient light interference. It can be used steadily in workshops and laboratories. Data does not drift over long-term measurements, providing reliable data support for standardized product quality control.

Different products have vastly different requirements for these two indicators: Mobile phone screens and car center consoles require not only high light transmittance but also extremely low haze; otherwise, the screen will look whitish, contrast will drop, and it will be impossible to see clearly under strong light. Lamp shades, frosted packaging, and cosmetic bottles require high light transmittance + high haze to let light through while making it soft and not glaring. Agricultural greenhouse films require a precise balance; they must ensure light penetration for photosynthesis while using scattered light to ensure crops receive light uniformly.

Whether in optical electronics, packaging and printing, construction glass, or the plastic and chemical industries, relying on the quantified data of the CHNSpec TH-110 Haze Meter allows you to escape subjective visual judgment and avoid parameter traps set by merchants.

Finally, here is a helpful summary: Light transmittance determines how "bright" a material is; haze determines how "clear" a material is.