OD Light Transmittance and Haze Meter

How to Choose the Right Light Transmittance Meter?

Light transmittance meters play a crucial role in measuring the visible light transmittance of various materials, ensuring consistent quality control across industries and eliminating reliance on subjective visual assessments. Whether testing automotive glass, plastic films, optical coatings, or window tint films, an accurate light transmittance meter helps guarantee consistent and uniform of products.

This article provides a comprehensive comparison of different light transmittance meters, including the LS110, LS116, LS117, and LS155 models. By understanding their applications and technical features, you can select the most suitable light transmission measuring device for your specific needs.

I. What is Light Transmittance & How Do We Measure It?

Visible light transmittance: Visible transmittance is the amount of light in the visible portion of the spectrum that passes through a glazing material.It describes the percentage of visible light (approximately 390 to 780 nanometers within the solar spectrum) transmitted through the glass. A lot of materials have VLT requirements. (Quoted from Wikipedia) Nowadays, we can get the VLT of the test material by the light transmittance testing instrument. Next, we will introduct four cost-effective light transmittance meters. The parameters of these light transmittance meters are listed below:

II. The Difference Between Regular Transmission And Diffuse Transmission

1. Regular transmission

The phenomenon that light deflects through a material with a smooth surface and a uniform medium and then deflects at the same angle is called regular transmission.

2. Diffuse transmission

The light passes through a material with a rough surface or an uneven medium, the transmitted light will be scattered in many directions because the light will be refracted at different angles on the rough materials' surface and at the junction of the uneven medium, this phenomenon is known as diffuse transmission.

• One key optical effect of diffuse transmission is wide-angle scattering, which results in haze. Haze occurs when light is scattered at large angles, leading to a milky or cloudy appearance. This phenomenon is particularly relevant in the evaluation of transparent plastics, films, and coatings, where excessive haze can impact both visual aesthetics and functional performance.

• Another effect associated with diffuse transmission is narrow-angle scattering, which affects clarity. Clarity describes how well fine details can be seen through a transparent material. When light is deflected at small angles, it results in a distortion of object outlines, making fine details harder to recognize. Unlike haze, clarity is highly dependent on the distance between the observed object and the material—the farther the object, the greater the distortion. This property is particularly important for automotive windshields, display screens, and high-precision optical materials, where maintaining high clarity ensures optimal visibility and sharp image reproduction.

By understanding the principles and difference of regular transmission and diffuse transmission, industries can better select materials with appropriate optical properties. Instruments such as a haze meter or an optical density meter help quantify these effects, ensuring that transparent materials meet specific quality standards.

III. Common Regular Transmission And Diffuse Transmission Materials

Regular transmission needs to meet the two characteristics of uniformity and transparency of the medium. We can determine whether the material is a regular transmission material in a simple way: observe the palm of your hand through the tested material. If you can clearly see the edge of the palm, then the measured material belongs to the regular transmission material; otherwise it belongs to the diffuse transmission material (provided that the light-transmitting material).

1. Regular transmission material

Note: The regular transmission materials listed above are for reference only

2. Diffuse transmission materials

Note: The diffuse transmission materials listed above are for reference only

IV. Which Light Transmission Measuring Device is Best for Your Needs?

LS110 Light Transmittance Meter: Designed with a split-type structure, this model is ideal for testing automotive glass. Its compact, two-part design allows for easy placement on car windows, ensuring accurate measurements even in confined spaces.

LS116 Light Transmittance Meter: With a parallel optical and detachable design that specializes in regular transmission materials such as optical glass, acrylic sheets, and coated films. It provides precise transmittance readings for industries requiring high optical clarity and minimal distortion.

LS155 Color Haze Meter can play a crucial role in ensuring that transparent materials meet industry standards for clarity, light transmittance, and optical performance, making it an essential tool in quality control and material development.

If the goal is to measure optical density, which is crucial for evaluating tinted glass, coated films, and lens ink, an optical density meter or optical densitometer, such as the LS117 Optical Density Meter, is recommended. The device is suitable for testing the light transmittance of opalescent translucent materials, matte materials.

V. FAQs

1. How to measure haze and transmittance simultaneously?

For measuring haze and transmittance simultaneously, simply use the LS155 Color Haze Meter. Select the “H/T” mode in the settings, place the material sample in the measuring area, and press the test button. The device will automatically display both haze (%) and transmittance (%) on the screen, providing quick and accurate optical measurements.

2. Can LS117 optical density meter test regular transmission materials?

Yes, the LS117 optical density meter is not only suitable for measuring all kinds of diffuse transmission materials, but also suitable for regular transmission materials. If you have multiple testing needs, it is recommended to choose this model. If you only need to measure uniform and transparent regular materials, the LS116 light transmittance meter is more cost-effective.

3. How accurate are your light transmittance meters?

In addition to the LS110 accuracy of ±2%, Linshang another light transmittance meters offer high-precision measurements with ±1% accuracy, ensuring reliable results.

4. Why is light transmittance important for automotive window tinting?

Many regions have strict visible light transmission (VLT) regulations for car window tinting. A window tint tester ensures that tinted windows comply with local laws, preventing excessively dark tints that reduce visibility and safety.

5. Where can I buy a reliable light transmittance meter?

Linshang offers a range of high-precision light transmittance meters, window tint testers, and optical density meters for various industries. Visit our website to explore our product lineup and find the perfect solution for your testing needs. If you have any other questions, please feel free to contact our customer service team.

6. Whether a traceable calibration certificate is included？

• The calibration certificate is not a standard configuration.If you need it, please pay additional calibration costs and wait patiently for the inspection duration of the device.

• The three Linshang light transmittance meters conform the relevant regulations and standards, and can pass the inspection of authoritative measurement agency (which has been approved by CNAS and ilac-MRA) and obtain a calibration certificate.