Research on Optical Detection Performance and Application of Multi-standard Compatible Haze Meter

Abstract

Haze is a core indicator for evaluating the optical uniformity of transparent and semi-transparent materials. As a special testing device, haze meter is widely used in quality control and material research and development of plastics, films, glass, display panels and other industries. Traditional haze meters generally have drawbacks such as limited supported standards, few light source types, long preheating time, slow testing speed and insufficient precision. Taking LISUN HM-120 haze meter/turbidimeter as the research object, this paper systematically elaborates the core performances of this haze meter, including compatibility with multiple testing standards of ASTM, ISO, JIS and national standards, simultaneous measurement with three light sources, preheating-free rapid detection and high-precision repeated measurement. It compares the parameter differences with HM-100 haze meter of the same series, and analyzes its optical path structure, hardware configuration and practical industrial application scenarios. Tests show that HM-120 haze meter requires no preheating and only takes 1.5 seconds for a single measurement. It can synchronously output haze and total transmittance data under three standard light sources of CIE-A, CIE-C and CIE-D65 with repeatability ≤0.05%, which can meet the full-process optical detection requirements of domestic and foreign laboratories and production workshops, providing an integrated solution for standardized detection of transparent materials.

Introduction

In industries such as plastic processing, optical glass, liquid crystal display panels and food & pharmaceutical packaging, material haze (HAZE) and total transmittance (T) directly determine product appearance, visual effect and service performance. The higher the haze value, the more serious the light scattering inside the material and the lower the imaging clarity; high transmittance represents excellent light penetration efficiency, and both together constitute the mandatory optical indicators for factory inspection of transparent materials.

A set of authoritative standards for haze detection have been formed worldwide: American ASTM D1003/D1044, international ISO 13468/ISO14782, Japanese JIS K7105/K7361/K7136, and China GB/T2410-2008. Import and export manufacturers, third-party testing institutions and material R&D laboratories all require haze meters to be compatible with multiple standards simultaneously to adapt to testing specifications of domestic and foreign customers.

Most conventional basic haze meters only support standards of a single region and are equipped with only 1~2 types of illumination light sources. They need 5~10 minutes of preheating after startup, and a single test takes 3~5 seconds, resulting in low efficiency for large batches of samples. The repeatability error of some low-end devices exceeds 0.1%, which cannot meet the high-precision testing requirements of high-end optical panels and precision optical glass.

LISUN HM-120 haze meter/turbidimeter has been optimized and upgraded for industry pain points, integrating three standard light sources, a full range of domestic and foreign testing standards, preheating-free optical path, dual measuring apertures and an Android intelligent touch control system. It takes both high-precision laboratory testing and rapid production line sampling inspection into account. This paper conducts a comprehensive analysis of its technical parameters, working characteristics and application scenarios.

Overall Technical Parameters and Hardware Configuration of HM-120 Haze Meter

Comparison of Core Specification Parameters
The parameter comparison between HM-120 haze meter and HM-100 basic haze meter of the same series is shown in Table 1 to intuitively reflect the upgrading advantages of HM-120.

It can be seen from Table 1 that HM-120 haze meter comprehensively surpasses the basic HM-100 haze meter in six dimensions including light source, standard compatibility, measuring aperture, repeat accuracy, operating system and data storage, making it a mid-to-high-end testing device balancing versatility and high precision.

Optical Path and Light Source System Design

HM-120 haze meter adopts the industry-general 0/D parallel light illumination and diffuse reflection receiving transmission optical path, matched with a large Φ154mm integrating sphere, which can completely collect the direct transmitted light and scattered light after passing through the sample, strictly meeting the mandatory requirements of each standard for optical path geometric structure.

The instrument is equipped with a 400~700nm full-spectrum LED light source covering the complete visible light range without measurement deviation caused by missing spectrum. It is built with three internationally general illumination light sources including CIE-A (incandescent lamp simulation light source), CIE-C (average daylight) and CIE-D65 (standard daylight), which can be switched with one click to synchronously output independent haze and transmittance values under the three light sources.

In export material testing, European and American customers usually adopt D65 light source to judge product appearance, while domestic national standards and Japanese industrial standards mostly adopt A and C light sources. HM-120 haze meter can switch light sources without hardware replacement, saving the procurement cost of multiple devices.

Analysis of Core Functional Characteristics of HM-120 Haze Meter

Compatibility with Full Series of Domestic and Foreign Testing Standards
This haze meter can easily realize haze measurement under both ASTM and ISO systems, fully covering the standard list: ASTM D1003/D1044, ISO 13468/ISO14782, JIS K7105, JIS K7361, JIS K7136, GB/T2410-08.

Testing logic varies among different standards: ASTM D1003 adopts the uncompensated method with simple testing procedures, suitable for rapid sampling inspection on production lines; ISO 13468 compensation method adds a light compensation structure to offset surface reflection loss of samples, delivering higher data accuracy and applicable to third-party testing and R&D of high-end optical materials; GB/T2410-08 equivalently adopts the international general integrating sphere testing method, which is the mandatory testing standard for plastic films in China.

Most haze meters only embed a single standard, requiring equipment replacement for enterprise submission inspection and export business. HM-120 haze meter can complete full-standard testing with one device, greatly reducing laboratory equipment investment.

 Preheating-free & 1.5-second Ultra-fast Data Output to Greatly Improve Testing Efficiency
The internal LED light source and photoelectric sensor of traditional integrating sphere haze meters have temperature drift characteristics, requiring 5~10 minutes of preheating after startup to stabilize the optical path, which leads to heavy time consumption for testing large batches of samples. HM-120 haze meter optimizes the light source temperature control circuit and signal acquisition module, with its optical path fully calibrated at constant temperature before delivery. It requires no preheating after startup and can perform measurement immediately after power-on calibration, with only 1.5 seconds for a complete test to synchronously output two groups of data including haze and total transmittance.

Taking daily sampling inspection of 2,000 groups of samples on a film production line as an example, each test with a traditional haze meter takes about 10 seconds including preheating waiting, resulting in over 5.5 hours of daily testing time; while each group only takes 1.5 seconds with HM-120 haze meter without preheating waiting, and the total daily testing time is less than 50 minutes, greatly improving production line quality inspection efficiency.

Dual Measuring Apertures and Open Sample Chamber Suitable for Various Specimens
HM-120 haze meter is equipped with two measuring apertures of 21mm and 7mm: the 21mm large aperture is suitable for films, flat glass and large-area plastic plates to reduce data fluctuation caused by local inhomogeneity; the 7mm small aperture is used for small-size samples such as mobile phone cover plates, optical lenses and small injection-molded transparent parts.

The instrument adopts an open measuring area without closed chamber, with no mandatory restrictions on sample length, width and thickness. It supports vertical placement of thin films and horizontal placement of heavy glass and liquid turbidity samples, realizing dual functions of haze meter and turbidimeter for both solid transparent materials and liquid turbidity testing.

Ultra-high Measurement Precision and Stable Repeatability
HM-120 haze meter covers the full range of 0~100%, with resolution of 0.01% for both haze and transmittance, and measurement repeatability ≤0.05%, halving the error compared with HM-100 haze meter with repeatability ≤0.1%.

Low repeat error is crucial for the high-end display industry: the allowable fluctuation range of haze for mobile phone screen protective films and LCD substrates is only ±0.1%. The repeat error of ordinary haze meters will cover the real batch differences of materials, while HM-120 haze meter can accurately capture tiny changes in optical performance to provide reliable data support for formula adjustment and production process optimization.

Intelligent Android Touch Control and Complete Data Management
The device is equipped with a 7-inch Android touch screen with visualized operation interface, supporting light source switching, standard switching, data storage and historical record query. Different from ordinary haze meters with limited storage, HM-120 supports mass data storage. It is connected to a computer via USB interface to export all test data with one click and automatically generate test reports, meeting the requirements of laboratory data traceability and product factory filing.

Industrial Application Scenarios of HM-120 Haze Meter

Plastic and Film Processing Industry
BOPP packaging films, PET optical films, PC plastic plates and injection-molded transparent containers all need haze and transmittance testing. Food packaging films require high transmittance and low haze to ensure product display effect. HM-120 haze meter can quickly sample and inspect optical indicators of film batches and complete factory inspection in accordance with GB/T2410-08; optical-grade light guide films need testing under ISO standard and D65 light source, and the device can switch standards with one click to meet export certification requirements of high-end film manufacturers.

Glass and Optical Component Industry
Automotive windshields, architectural tempered glass, optical lenses and mobile phone cover plates have strict haze control requirements, and low haze ensures clear vision. The 7mm small aperture of HM-120 haze meter is used for testing small glass lenses, and the 21mm aperture for whole flat glass, which can be placed vertically or horizontally freely. It outputs transmittance data under three light sources simultaneously to meet dual testing specifications of national standards for the automotive industry and ASTM standards of Europe and America.

Display Panel Industry
Haze of LCD display screens, backlight modules and optical protective films directly affects screen display effect, and this industry generally requires repeatability error lower than 0.05%. The high-precision optical path and preheating-free rapid testing feature of HM-120 haze meter adapt to uninterrupted sampling inspection on production lines of panel factories, and multi-light-source data can be used to simulate screen visual performance under different lighting environments such as indoor and outdoor conditions.

Packaging, Medical and Liquid Turbidity Testing
Haze testing of transparent pharmaceutical packages, medical infusion tubes and transparent reagent bottles is required to judge material cleanliness. Meanwhile, the instrument can be used as a turbidimeter to test transparent liquid samples. The open chamber can hold liquid cuvettes to realize dual-purpose testing for solid and liquid samples, adapting to laboratory testing demands of chemical industry, water quality and medical devices.

Summary of Instrument Application Advantages

• Full coverage of standards: One haze meter is compatible with all mainstream haze testing standards of the United States, Europe, Japan and China, adapting to multi-scenario certification demands of import and export enterprises and third-party testing institutions;

• Simultaneous measurement with three light sources: Free switching among CIE-A/C/D65 three standard light sources, obtaining three groups of optical data in one measurement to meet testing specifications of different regions;

• Efficient preheating-free testing: No waiting for preheating, ultra-fast output of haze and transmittance results within 1.5 seconds, greatly improving testing efficiency for large batches of samples;

• High-precision stable measurement: Repeatability ≤0.05% and high resolution of 0.01%, suitable for precision R&D and quality control of high-end optical materials;

• Strong sample compatibility: Dual measuring apertures and open unlimited sample chamber, vertical and horizontal dual-purpose for both solid and liquid samples;

• Intelligent data management: Android touch operation, mass data storage and convenient USB export to meet laboratory data traceability management requirements.

Conclusion

Haze meter is an indispensable core device for quantitative detection of optical performance of transparent materials. Targeting the current industry demands of multi-standard, high-precision and high-efficiency testing, LISUN HM-120 haze meter/turbidimeter has undergone all-round optimization, breaking through the defects of traditional haze meters such as single light source, limited standard support, long preheating time and insufficient precision. The instrument can synchronously implement two mainstream haze testing methods of ASTM and ISO, equipped with three standard light sources of CIE-A, CIE-C and CIE-D65, delivering fast data output within 1.5 seconds without preheating with ultra-high repeatability error ≤0.05%. Matched with dual-aperture open measuring structure, it covers full-field testing scenarios including plastic films, optical glass, display panels, medical devices and liquid turbidity.

Against the background of global manufacturing, an integrated haze meter meeting multiple national testing standards can effectively reduce enterprise equipment procurement costs, shorten testing hours and improve the authority of test data. Taking both precise laboratory R&D and batch sampling inspection on production lines into consideration, HM-120 haze meter is the preferred device for optical detection of transparent materials, which can provide stable, accurate and standardized data support for material formula optimization, production process control and import & export product certification.