Research on Technical Principle and Application of RoHS Tester

Abstract:
The RoHS tester is core equipment for hazardous substance compliance testing of electrical and electronic products. Based on energy‑dispersive X‑ray fluorescence (EDXRF) technology, the LISUN EDX‑2A RoHS tester realizes qualitative and quantitative elemental analysis by analyzing the wavelength and intensity of characteristic X‑rays emitted by samples. It can accurately detect hazardous substances restricted by RoHS directives, such as lead, mercury, and cadmium. This paper focuses on the technical principle, performance, testing standards, and application scenarios of the LISUN EDX‑2A RoHS tester, illustrates its technical advantages with actual parameters, and provides a reliable reference for RoHS compliance testing in the electronic and electrical industry.

1. Background and Testing Standards of RoHS Tester

Against the background of increasingly stringent global environmental regulations, the EU RoHS Directive has become a critical threshold for electronic and electrical products entering the international market. As a dedicated instrument for product hazardous substance testing, the accuracy and efficiency of the RoHS tester directly determine enterprises’ market access capabilities.

The RoHS Directive, officially implemented in 2006, has been revised several times. RoHS 2.0 (2011/65/EU) includes medical devices and monitoring equipment and requires manufacturers to issue EC declarations of conformity and retain technical files for at least ten years.

The RoHS Directive strictly limits the content of six hazardous substances:

• Cadmium (Cd): 100 ppm

• Lead (Pb), Mercury (Hg), Hexavalent Chromium (Cr⁶⁺), Polybrominated biphenyls (PBBs), Polybrominated diphenyl ethers (PBDEs): 1000 ppm

To meet these testing requirements, SJ/T 11365‑2006 specifies X‑ray fluorescence (XRF) as the preferred method for RoHS rapid screening. This method features non‑destructive testing, fast analysis, and simple operation, making it the core technical support for industrial RoHS testers. The LISUN EDX‑2A RoHS tester is a professional instrument developed based on XRF technology, fully compliant with domestic and international RoHS testing standards, enabling accurate screening of hazardous elements in electronic and electrical products.

2. Core Technical Principle of LISUN EDX‑2A RoHS Tester

The core working principle of the LISUN EDX‑2A RoHS tester is energy‑dispersive X‑ray fluorescence spectrometry. It analyzes the wavelength and intensity of characteristic X‑rays emitted by the sample to achieve qualitative and quantitative elemental analysis.

The instrument is equipped with a high‑energy X‑ray source that emits X‑rays of specific energy to bombard the sample. Atoms in the sample are excited, causing inner‑shell electrons to transition. When outer‑shell electrons fill the vacancies, they release characteristic X‑rays unique to each element.

• Different elements have different atomic structures, so their characteristic X‑ray wavelengths are unique, which is the basis for qualitative analysis.

• The intensity of characteristic X‑rays of the same element is positively correlated with its content in the sample. By comparing the measured spectral intensity with that of standard samples, quantitative analysis can be achieved.

Compared with traditional testing methods, the LISUN EDX‑2A RoHS tester has obvious advantages:

• Non‑destructive testing: No damage to samples during testing.
• Simple sample preparation: Solid, liquid, and powder samples can be tested directly.
• Wide detection range: Covers all RoHS‑restricted elements, with a detection range from 2 ppm to 99.99%.

The built‑in Si‑pin detector has a resolution of 149 eV, which accurately identifies characteristic X‑ray spectra and avoids errors caused by spectral overlap, ensuring the accuracy of RoHS test results.

3. Performance Parameters and Core Features of LISUN EDX‑2A RoHS Tester

As a professional RoHS tester, the LISUN EDX‑2A adopts a non‑vacuum bench‑top structure, with a weight of 50 kg and a sample chamber size of 610×320×100 mm, suitable for testing products and components of various sizes.

Table 1 Comparison of Core Performance Parameters of LISUN EDX‑2 Series RoHS Tester

Specification	EDX‑2A (Basic RoHS tester)	EDX‑2AC (With coating testing)	Application Notes
Type	Non‑vacuum bench‑top	Vacuum bench‑top	EDX‑2A works under atmosphere, easy operation
Test time	200 sec	100 sec	EDX‑2A meets high‑efficiency batch screening
Test environment	Atmospheric	Vacuum	EDX‑2A requires no vacuum system
Detector	Si‑pin	SDD	Both suitable for RoHS element detection
Resolution	149 eV	129 eV	High resolution for accurate spectrum recognition
Sample type	Solid, liquid, powder	Solid (vacuum); solid/liquid/powder (non‑vacuum)	EDX‑2A supports more sample types
Content range	2 ppm – 99.99%	2 ppm – 99.99%	Fully covers RoHS limit requirements
Main function	RoHS testing	RoHS + coating thickness testing	EDX‑2A focuses on professional RoHS screening

Core advantages of LISUN EDX‑2A RoHS tester:

• Imported core components: Stable performance for long‑term continuous testing.
• Visual testing: Built‑in camera and lighting for accurate positioning.
• Intelligent control: Automatic adjustment of voltage (50 kV) and current (600 μA).
• Multiple safety protections: Overcurrent and short‑circuit protection.
• Standard samples included: Ag reference sample and EU certified standards for easy calibration.

4. Application Scenarios and Testing Process

The LISUN EDX‑2A RoHS tester is widely used in the entire industrial chain of electronic and electrical products:
• Electronic components: Resistors, capacitors, chips, connectors.
• Plastic parts: Shells, accessories, flame‑retardant components.
• Metal parts: Brackets, fasteners, structural parts.
• Finished products: Final inspection before delivery.

Standard testing process:
• Sample preparation: Place the sample in the test chamber.
• Parameter setting: Select RoHS test mode.
• Start test: The instrument automatically excites and collects spectra.
• Data analysis: Software identifies elements and calculates content.
• Compliance judgment: Automatically compare with RoHS limits and generate reports.

5. Industry Value and Development Prospect

With the global trend of green manufacturing, the RoHS tester has become essential equipment for enterprises. The LISUN EDX‑2A provides an ideal balance between laboratory‑level accuracy and production‑line efficiency.

As RoHS regulations continue to upgrade, LISUN will further integrate digital and intelligent technologies to realize cloud data management, automatic analysis, and wider element coverage. The LISUN EDX‑2A RoHS tester will continue to provide stable, reliable, and efficient support for global RoHS compliance.

6. Conclusion

The RoHS tester is key to ensuring the safety and environmental compliance of electronic and electrical products. Based on energy‑dispersive X‑ray fluorescence technology, the LISUN EDX‑2A RoHS tester achieves accurate, fast, and non‑destructive detection of RoHS hazardous elements by analyzing the wavelength and intensity of characteristic X‑rays.

It meets international and domestic testing standards and is widely used in incoming inspection, production control, and finished product inspection. The LISUN EDX‑2A not only helps enterprises pass global compliance inspections but also promotes the sustainable development of the industry.

Tags：EDX-2A