Sheet Resistance Testing Method - Four-probe Measurement Method

HJT Solar Cell

TOPCon Solar Cell

Perovskite & Organic Photovoltaic

BC Solar Cell

IEC61215 & IEC61730 Testing Standards

PV Monitoring Base Station

Power Plant Maintenance Testing

BIPV Photovoltaic Building Trial

Crystalline Silicon Solar Cells Cleaning and Texturing Diffusion Junction Formation Coating Grid Line Characterization Solar Cell QC Inspection IEC Quality Testing Standards Module QC Inspection Perovskite Solar Cells Perovskite Online Detection Power Station Maintenance Monitoring

Quantum Efficiency Tester PL/EL Integrated System

PV-Reflectumeter 3D Confocal Microscope

In-Line Four Point Probe Tester Four Point Probe Tester In-Line Thin Film Thickness Tester Raman Spectrometer FTIR Spectrometer

Spectrophotometer Automatic Spectroscopic Ellipsometer

Contact Resistance Tester Ultra depth of field 3D microscope Auto Visual Tester VMM PV Vision Measuring Machine Solar Cell Horizontal Tensile Tester

Steady State Solar Simulator for Solar Cell Solar Cell UV Aging Test Chamber Solar Cell Comprehensive Tensile Tester

Visual Inspection Tester Wet Leakage Current Tester PV Module EL Tester PV Module UV Preconditioning Chamber Steady State Solar Simulator for PV Module Current Continuous Monitor Potential Induced Degradation Test Bypass Diode Tester LeTID Test System Reverse Current Overload Tester Impulse Voltage Tester Hipot Insulation Tester Ground Continuity Tester Hipot Insulation Ground Tester Damp Heat Test Chamber Humidity Freeze Test Thermal Cycle Test Chamber Dynamic Mechanical Load Tester Static Mechanical Load Tester Hail Impact Tester Robustness of Termination Tester Module Breakage Tester Cut Susceptibility Tester Peel Shear Strength Tester

Universal Testing Machine (Single-arm) Universal Testing Machine (Double-arm) Glass Transmittance Tester Acetic Acid Test Chamber EVA Degree of Crosslinking Test System Junction Box Comprehensive Tester Drop ball tester

Semi-automatic scanning four-probe tester Stylus Profilometer Maximum Power Point Tracker

Perovskite Glass Transmittance Tester Perovskite P1 Laser Scribing Multifunctional Testing Machine Perovskite Online PL Tester Perovskite Online Sheet Resistance Tester Online Perovskite Film Thickness Tester Perovskite Process Inspection Workstation

Portable IV Curve Tester Portable EL Tester Portable Thermal Imaging Tester Solar Module Multi-Channel Testing System PV Inverter Power Quality Tester Drone EL Tester

Quantum Efficiency Tester

The MNPVQE-300Pro quantum efficiency tester is a common tool in photovoltaic research and production line quality processes, used for accurately determining the spectral response/EQE (IPCE) and IQE of solar cells.

The MNPVQE-300Pro is compatible with various types of photovoltaic devices, materials, and architectures, including c-Si, mc-Si, a-Si, µ-Si, CdTe, CIGS, CIS, Ge, dye-sensitized, organic/polymer, tandem, multi-junction (2-, 3-, 4-junction, etc.), quantum wells, quantum dots, chalcogenides, and perovskites.

PL/EL Integrated System

Offering high-precision detection of internal defects in crystalline silicon solar cells, such as crystal defects and impurities. This enables production personnel to promptly adjust process parameters and improve product quality.

The ME-PSC-PL/EL tandem features an intelligent detection system that can customize defect identification based on defect types, including black spots, pinholes, black corners, scratches, and more.

PV-Reflectumeter

The RTIS Matte Reflectance Tester can measure the reflectance intensity of textured surfaces at different wavelengths. The test results are processed by software to calculate the photoelectric signals, ultimately presenting them as visual curves, which facilitates users in systematically characterizing the reflectance properties of the textured surfaces.

It is suitable for various front-end processes such as 「texturing of monocrystalline and polycrystalline silicon, coating, etching, and wet/dry black silicon」 measuring parameters like the inversion rate, minimum wavelength point of reflectance, and total reflected energy within specified wavelength ranges for rough surfaces.

3D Confocal Microscope

The ME-PT3000 is a specialized optical instrument for detecting the surface quality of photovoltaic (PV) cells. Based on optical principles, it combines a precision Z-axis scanning module with 3D modeling algorithms to achieve non-contact 3D scanning and imaging. This allows for the quantitative measurement of busbar height/width and the number of textured pyramids, providing feedback on the quality of cleaning, texturing, and screen printing processes.

The device features a floor-standing confocal microscope structure, equipped with a damping isolation mechanism to minimize environmental vibrations. Through a matrix scanning method and signal processing algorithms, it supports high-precision 3D measurements and high-definition focused imaging, making it suitable for quality monitoring during the PV cell production process.

In-Line Four Point Probe Tester

FPP230 Auto is an In-Line Four Point Probe Tester specifically designed for “photovoltaic process monitoring.” It can quickly and automatically scan samples up to 230 mm in size, obtaining resistivity/resistance distribution information at different positions on the sample.

With the increasing level of automation among customers, the FPP230 Auto, featuring 1-9 point in-line four-probe testing with ultra-high precision and flexible design, has received widespread acclaim from automation manufacturers and customers.

Four Point Probe Tester

FPP230A is a automatic four point probe tester designed specifically for scientific research. It can quickly and fully automatically scan samples up to 230mm in size, obtaining resistivity/resistance distribution information from different locations on the sample.

The dynamic testing repeatability for ITO films can reach 0.2%, which is industry-leading. With an ultra-wide measurement range of 1mΩ to 100MΩ, it covers the vast majority of application scenarios and is widely applicable in fields such as photovoltaics, semiconductors, alloys, and ceramics.

In-Line Thin Film Thickness Tester

The POLY5000 is an in-line thin film thickness tester specifically designed for monitoring photovoltaic processes. It can perform rapid, automatic 5-point synchronous scanning of samples, monitoring the thickness and optical constants of various films on the "industrial production line". It provides fast and accurate measurements of film thickness, optical constants, and other information, with customizable measurement dimensions based on customer sample sizes.

Utilizing Millennial's mature "film thickness measurement" technology, the POLY5000 enables users to optimize film thickness characteristics and monitor process stability in real-time.

Raman Spectrometer

The Millennial Solar Galaxy Solar crystallization rate tester is suitable for both spectroscopy and imaging, featuring a high spectral resolution and extremely low stray light. This ensures the accuracy and repeatability of spectral data. A series of new technologies for Raman spectral imaging have been introduced, significantly enhancing the quality and speed of Raman spectral imaging. The novel imaging algorithms can extract useful spectral information from complex big data.
The unique high-efficiency asymmetric optical path design, combined with axial scanning of the grating, suppresses stray light and eliminates diffracted light, ensuring that customers can quickly and accurately obtain high signal-to-noise ratio spectra and images.

FTIR Spectrometer

Fourier Transform Infrared Absorption Spectroscopy (FTIR) is a powerful tool for studying the relationship between the emission or absorption of radiation by various molecules in the infrared spectrum and their molecular structures. It is primarily used for the analysis of material structures.
The infrared absorption spectrum can be utilized to investigate the configuration and distribution of Si-H bonds in amorphous silicon and microcrystalline silicon materials.

Spectrophotometer

The UVN2800-Pro spectrophotometer features a unique dual-beam optical design that effectively corrects for absorbance variations caused by different sample matrices, allowing for stable sample measurements. It offers a wide testing range, high precision, and excellent stability.

The UVN2800-Pro spectrophotometer supports the measurement of solar transmittance across a broad wavelength range from the ultraviolet to the near-infrared region, providing strong support for the efficiency analysis of solar cells.

Automatic Spectroscopic Ellipsometer

The UVPLUS SE Spectroscopic Ellipsometer is a high-performance, specialized spectral ellipsometer developed by Millennial Solar for the research and quality control of photovoltaic solar cells. It covers a wavelength range from ultraviolet to visible and near-infrared.

The device features a highly sensitive detection unit and spectral ellipsometry analysis software, specifically designed to measure and analyze the layer structure parameters (such as thickness) and physical parameters (such as refractive index n and extinction coefficient k) of single or multilayer nanofilms in the photovoltaic field.

Contact Resistance Tester

In the optimization of solar cell electrodes, contact resistance is an important aspect to consider. The magnitude of contact resistance is not only related to the contact geometry but also to the diffusion and sintering processes. Measuring contact resistivity can reflect issues present in the diffusion, electrode fabrication, and sintering processes.

The TLM-STD contact resistivity tester offers two testing functions:
Contact resistivity testing and line resistance testing, which can be switched between.

The contact resistivity testing is primarily used to measure contact resistance, thin film resistance, and contact resistivity;
The line resistance testing is used to measure the line resistance of grid lines.

Ultra depth of field 3D microscope

The ME-UD6300 Ultra Depth-of-Field Microscope is a detection instrument designed for sub-micron level measurements of various precision components and material surfaces. It utilizes high numerical aperture objectives and apertures, adjusting the size of the light spot and the position of the aperture to achieve varying degrees of focus at different depths, thereby realizing the ultra depth-of-field effect. Combined with a precise Z-axis scanning module and 3D modeling algorithms, it performs non-contact scanning of the component surface and constructs a 3D image of the surface. The system software processes and analyzes the 3D image data, obtaining 2D and 3D parameters that reflect the surface quality of the component, thus enabling optical detection for 3D measurement of the surface morphology.

Auto Visual Tester

Millennial AVT-4030 Auto Visual Tester integrates size, defect, film thickness, and tension detection into one, achieving high precision, high efficiency, and comprehensive defect detection for photovoltaic screen printing, as well as line width, line spacing, and shrinkage measurement. It is the ideal quality inspection assistant for quality control (QC) personnel.

The AVT-4030 employs advanced image processing technology and algorithms, featuring a user-friendly interface that allows operations to be completed in just a few steps. It also includes measurement and data statistical analysis functions to help customers analyze and improve their processes.

VMM PV Vision Measuring Machine

Millennial Vision Measuring Machine equipped with a measurement system based on a high-resolution camera, allowing for fast and accurate measurement of various components.

VMM PV Basic Module: Used for detecting the patterns of photovoltaic panels, 2D planes, as well as measuring bus bar width, spacing, and the printing quality of PT values.

Exclusively Developed Metal Coverage Rate Module: This module is specifically designed to calculate the coverage ratio of silver bus bars over the entire solar cell. It can quickly and automatically compute the coverage ratio using a visual graphical method, comparing it with the originally designed ratio to identify any discrepancies.

Solar Cell Horizontal Tensile Tester

In the photovoltaic industry, during the incoming material inspection of solar cells, bending tests and solder strip peel strength tests are conducted to evaluate the quality of the bus bar welding. The ME-CELL-HTT is a horizontal tensile testing machine specifically designed for 180° peel tests on solar cells.
The testing machine has a load range of 0N to 100N and provides testing solutions with exceptional accuracy and reliability. It features a data acquisition frequency of up to 50Hz and a force measurement accuracy of ±0.5% of the full scale at 1/1000 resolution, offering high flexibility.

Steady State Solar Simulator for Solar Cell

The Millennial Steady State Solar Simulator for Solar Cell utilizes metal halide lamps that simulate full-spectrum light sources to replicate destructive light waves present in various environments. It provides corresponding environmental simulation and accelerated testing for photovoltaic solar cell product development and quality control.

Light exposure tests comply with the stability test requirements specified in clauses MQT08 and MQT09 of the IEC 61215 standard. The irradiation area can be as small as 600×600 mm, and the light intensity meets BBA standards.

Solar Cell UV Aging Test Chamber

The Millennial Solar Cell UV Aging Test Chamber for Photovoltaic Solar Cells is a device specifically designed to simulate the ultraviolet radiation in the natural environment and conduct accelerated aging tests on photovoltaic solar cells.

The test is carried out in accordance with the provisions of the MQT10 clause in the IEC61215 standard. The minimum irradiation area can be made to be 700×900mm. Its core function is to evaluate the weather resistance, anti-aging performance, and reliability of materials under long-term outdoor exposure through controllable conditions such as ultraviolet light sources and temperature and humidity regulation.

Solar Cell Comprehensive Tensile Tester

The Millennial Solar Cell Comprehensive Tensile Tester has a horizontal module testing function. It can conduct a horizontal 180° solder strip peel strength test, with 28 sensors in use simultaneously. It can also perform cell bending tests, meeting three point and four point bending test requirements.

This equipment meets the installation and testing needs of solar cells of various specifications from current mainstream manufacturers and is widely favored. It is specifically used for testing the peel force, tensile strength, etc. of related products in the photovoltaic industry, such as silicon materials, silicon wafers, and battery components.

Visual Inspection Tester

Appearance defects of photovoltaic modules (such as cracks, bubbles, delamination, etc.) may intensify during subsequent tests and have an adverse impact on the performance of the modules.
The Millennial Visual Inspection Tester is used to detect any appearance defects in photovoltaic modules, meeting the requirements of MQT01 appearance inspection in the IEC61215 - 2:2021 standard.

Wet Leakage Current Tester

Wet Leakage Current Tester is used to verify the influence of moisture caused by rain, fog, dew or melting snow on the circuit caused by corrosion, leakage or safety accidents,ensure that the insulation performance of the module complies with the standards.
This equipment meets the test standards of IEC 61215-2:2021, IEC 61730-2:2016, and UL 1703-2015.

PV Module EL Tester

The EL tester for photovoltaic modules in the laboratory is a high-precision detection device based on the principle of electroluminescence (EL). It is mainly used to evaluate the internal defects and performance of photovoltaic modules, ensuring the product quality and reliability.

PV Module UV Preconditioning Chamber

The Millennial PV Module UV Preconditioning Chamber for photovoltaic modules is a specialized device used to simulate the ultraviolet radiation in the natural environment and conduct accelerated aging tests on photovoltaic modules.
The test is carried out in accordance with the MQT10 clause of the IEC61215 standard. The irradiation area can reach 5800×2800mm (capable of simultaneously testing 4 components with the specification of 2500×1400×50mm). Its core function is to evaluate the weather resistance, anti - aging performance, and reliability of materials under long - term outdoor exposure through controllable UV light sources, temperature and humidity regulation, and other conditions.

Steady State Solar Simulator for PV Module

The Millennial Steady State Solar Simulator uses metal halide lamps that can simulate full - spectrum light sources to reproduce the destructive light waves present in different environments. It can provide corresponding environmental simulation and accelerated tests for the product development and quality control of photovoltaic modules.
The light exposure test is carried out in accordance with the stability tests specified in the MQT08 and MQT09 clauses of the IEC61215 standard. The irradiation area can reach 6040×2560 mm, and the light level meets the BBA standard.

Current Continuous Monitor

The current continuity test system is for IEC61215 standard 10.11 high and low temperature cycle experiment clause, 10.12 wet freezing experiment clause. Mainly includes the provision of stable direct current, current recording, temperature recording and temperature control functions, through the temperature control of the DC power supply, the multi-channel current, multi-channel temperature long-term real-time monitoring. With the use of high and low temperature cycle box, it can monitor the internal circuit connectivity of multiple components.

Potential Induced Degradation Test

Long-term leakage current will cause changes in the state of the cell carriers and depletion layer,corrosion of the contact resistance in the circuit,and electrochemical corrosion of packaging materials.This results in cell power attenuation,increased series resistance,reduced light transmittance,delamination and other phenomena that affect the long-term power generation and life of the module.
The PID (Potential Induced Degradation) resistance test is often combined with thermal cycling (MQT11), wet-freeze cycling (MQT12), etc., to simulate the comprehensive failure modes of the modules in complex environments.

Bypass Diode Tester

The Bypass Diode Tester is a core inspection device specifically designed for photovoltaic modules, which is used to evaluate the conduction performance, thermal stability, and durability of bypass diodes under extreme operating conditions. As the "safety valve" of photovoltaic modules, bypass diodes can effectively prevent the hot spot effect and ensure that the modules can still operate safely when there is partial shading or when solar cells fail.
This system verifies the key parameters of the diodes by accurately simulating the actual application scenarios, ensuring the long-term reliability of the modules and reducing the operation and maintenance risks of the power station.

LeTID Test System

Reverse Current Overload Tester

During the application of solar cells, due to voltage drops, they may be reversely charged by other cell strings. If the reverse charging current does not reach the protection current of the cell string fuse, the module may be reversely charged for a long time, with the temperature continuously rising, thus damaging the module.
This test provides a reverse power supply to reversely charge the solar cells, simulating actual operating conditions to test the module's ability to withstand reverse current. It is applicable to Clause MST26 in the IEC61730 standard.

Impulse Voltage Tester

The Millennial Impulse Voltage Tester is a key device specifically designed to evaluate the insulation performance and reliability of photovoltaic modules under transient overvoltage conditions such as lightning strikes and switching surges.
Its core function is to simulate the pulse voltage waveforms specified in international standards like IEC 61730 (such as 1.2/50μs), and verify the withstand capability of the internal materials of the modules (such as the encapsulation adhesive film and backsheet) and the circuits under extreme voltage impacts, so as to prevent risks such as hot spot effects, electric leakage or fires caused by insulation failures.

Hipot Insulation Tester

The photovoltaic hipot insulation tester is a specialized device used to evaluate the insulation performance and withstand voltage capability of photovoltaic modules and electrical equipment. It mainly detects the leakage current, insulation resistance, and withstand voltage strength of these components in a high-voltage environment to ensure that the products meet the safety standards and prevent the risks of fires or equipment damage caused by insulation failures. The core functions include:

Insulation Resistance Test: Measure the insulation performance of the internal materials of the module (such as EVA adhesive film and backsheet) to ensure there are no potential risks of electric leakage.
AC/DC Withstand Voltage Test: Simulate transient high-voltage environments such as lightning strikes and power grid surges to verify the long-term withstand capability of the module.
Arc Detection: Identify the phenomena of partial discharge or arcs under high voltage to a

Ground Continuity Tester

The Ground Continuity Tester is a key device specifically designed to evaluate the reliability of the grounding system of photovoltaic modules. Its main function is to detect the resistance value between the metal frame of the photovoltaic module, the junction box, and the grounding conductor, ensuring that the grounding continuity meets the safety standards.
This device measures the resistance of the grounding loop by applying a constant direct current to verify the electrical safety performance of the modules under extreme conditions (such as lightning strikes and electric leakage).

Hipot Insulation Ground Tester

ME-PV-HIG developed by Millennial Solar for photovoltaic industry automated testing systems, the ME-PV-HIG combines withstand voltage testing, insulation resistance measurement, and ground continuity verification in one advanced device. Standard with data acquisition software and supporting remote firmware updates via USB, it fully complies with photovoltaic standards IEC 61215 and IEC 61730.

Damp Heat Test Chamber

Solar modules must withstand harsh climatic conditions during application. Among these, the high-temperature and high-humidity environment (DH test) is a core testing item for evaluating photovoltaic module reliability and material durability.
This test simulates extreme "dual 85" conditions (85°C temperature and 85% RH humidity, compliant with international standards such as IEC 61215 and UL 1703). Combined with continuous cyclic testing for over 1,000 hours, it systematically validates electrical performance degradation, encapsulation material failure, and long-term reliability predictions for modules.

Humidity Freeze Test

During the application process of solar modules, they will be subjected to the tests of various harsh weather conditions. Among them, the performance of the modules, such as their ability to withstand high temperature and high humidity as well as the subsequent impact of low temperature, and their ability to withstand long-term moisture penetration, needs to be evaluated. The HF test is carried out to verify and evaluate the reliability of the modules or materials, and to identify manufacturing defects at an early stage by inducing failure modes through thermal fatigue.

Thermal Cycle Test Chamber

The Millennial Thermal Cycle Test Chambe is a reliability testing device specifically designed for solar modules. It accurately simulates a rapidly alternating environment of high and low temperatures to verify the performance, structural stability, and long-term durability of module products under extreme temperature conditions. Moreover, by inducing failure modes through thermal fatigue, it helps users detect potential defects in advance, thus improving product quality and market competitiveness.

Dynamic Mechanical Load Tester

Mechanical performance assessment is required for both photovoltaic (PV) modules and building - integrated photovoltaic (BIPV) systems. This assessment is a crucial step in ensuring the long - term functionality of these systems and optimizing commercial products. Performance tests are carried out through methods such as mechanical loading (ML), inhomogeneous mechanical loading (IML), and dynamic mechanical loading (DML) to verify the performance of PV modules under external mechanical loads, ensuring that the modules are free from visual damage and significant loss of electrical functionality.
Dynamic Mechanical Load Tester meets the requirements for static mechanical load testing in Article 4.15 of IEC61215 - 2016 standard, Clause MST34 of IEC61730 - 2016 standard, and Clause 41 of UL1703 standard. It is controlled by an 84 - channel pressure sensor, with each cylinder independently controlled. The suction cup spacing is adjustable, and it has a universal structure to ensure

Static Mechanical Load Tester

The static mechanical load tester for photovoltaic modules is a specialized device used to simulate the static mechanical loads (such as wind pressure, snow pressure, ice accumulation, etc.) that photovoltaic modules bear during actual outdoor installation. By applying continuous pressure or tensile force, it evaluates the structural strength, material durability, and electrical performance stability of the modules.
Its core objective is to verify the compression - resistance, bending - resistance, and tensile - resistance capabilities of the modules in extreme environments, ensure that they comply with international safety standards (such as IEC 61215, IEC 61730, UL 1703, etc.), and reduce the risk of failure during outdoor operation.

Hail Impact Tester

During the operation of a photovoltaic (PV) system, PV modules face various environmental challenges, including hail. When hailstones strike the surface of PV modules at high speed, they may cause serious impacts such as surface damage, cell damage, and broken connection wires. Therefore, understanding the impact of hail on PV modules and the modules' impact - resistance capabilities is crucial for ensuring the reliability and durability of the PV system.
This hail impact testing machine is based on IEC61215 standard MQT17 development of hail test equipment, through the pressure impact of different diameter (artificial ice balls used to simulate hail) ice balls, and at constant speed impact components, simulate the impact of hail climate on components, verify the ability of components to resist hail impact.

Robustness of Termination Tester

This test is for IEC61215 standard MQT14 in the design and development of the leading end strength test system, testing machine is divided into tensile testing machine, torsion testing machine, adhesion testing machine 3 products.
Simulation component in the installation process, the component lead end is unintentionally or intentionally pulled, the equipment to a certain quality of weight applied in the lead end reciprocating pull to judge the lead end tensile performance; The equipment uses the motor to exert a certain torsion force on the lead wire, so as to judge the performance of the lead wire torque resistance.

Module Breakage Tester

The module breakage tester is a specialized testing equipment dedicated to evaluating the impact resistance performance of photovoltaic modules (especially BIPV). Its core function is to simulate the scenarios of the glass surface being impacted by the human body or objects, and verify the safety of the modules under extreme mechanical loads.。
The module cracking testing machine is a testing device developed based on Clause MST32 of the IEC61730 - 2 standard to test the ability of photovoltaic modules to resist heavy-object impacts. This machine is equipped with a controllable lifting system. It raises an impact bag filled with lead balls and wrapped in glass ribbon. When the impact bag freely falls from different vertical heights, it generates kinetic energy that acts on the surface of the photovoltaic module. This is to verify the risk of scratches or stabbing injuries after the tempered glass is cracked by the impact.

Cut Susceptibility Tester

Solar panels have plastic materials on their surface. During any process of production, installation, and operation, they may be scratched when touched by sharp objects, affecting the insulation of the panels. In severe cases, the internal charged parts will be exposed, resulting in the risk of electric shock.
This solution is an automatic testing equipment developed according to IEC61730, UL1703, and ASTM E2685-2009 standards. It is used to test whether the components with polymer materials as the front and back surfaces can withstand the routine operations during installation and maintenance without the risk of electric shock.

Peel Shear Strength Tester

Peel Shear Strength Tester is an innovative dual-function equipment developed through years of PV product testing and research, specifically designed for both peel testing and adhesion testing of photovoltaic modules. Its technical specifications fully comply with the requirements of IEC 61730-2:2016 standards.

Universal Testing Machine (Single-arm)

The Millennial Universal Testing Machine (Single-arm) adopts a compact single-column design. Tailored for the small-load, high-precision testing demands of photovoltaic materials, it is ideal for key components such as solder strips, encapsulation films, and junction box connectors.
Capable of performing tension, peeling, and bending tests, it accurately measures tensile strength, elongation at break, and bonding performance. Supporting rapid production-line spot checks and R&D verification, it serves as a specialized device for testing the mechanical properties of photovoltaic module materials.

Universal Testing Machine (Double-arm)

The Millennial Universal Testing Machine（Double-arm is a high-precision and high-stability mechanical testing device. Centered around a double-column gantry structure, it features high stability and large load-bearing capacity. It is specifically designed for verifying the strength of materials such as PV glass, aluminum alloy frames, and backsheets.
It supports three-point bending, compression, and biaxial tension tests, and can measure key parameters like the wind pressure resistance of tempered glass and the fatigue life of frames, meeting the requirements of UL 1703 and IEC 61730 standards.

Glass Transmittance Tester

Glass Transmittance Tester PGT2400 is a powerful tool for photovoltaic glass performance testing. It has high-precision measurement accuracy and stability. It can measure the transmittance of the sample, calculate the AM1.5 effective solar transmittance, visible light transmittance, Y, x, y, L*, a*, b* and other color parameters of ultra-white embossed glass, and display CIE color coordinates and chromaticity diagrams.
Equipped with an air floating platform, it ensures that when measuring the moving glass, there is frictionless movement to reduce wear and save manpower for carrying glass.

Acetic Acid Test Chamber

Photovoltaic modules usually use EVA (ethylene-vinyl acetate copolymer) adhesive film to encapsulate solar cells. During the long-term exposure and use outdoors, in addition to the erosion of water vapor, the EVA adhesive film will also degrade to generate acetic acid and olefins. The escaped acetic acid can corrode the electrode grid lines, solder ribbons, etc. of the solar cells, affecting the output power and safety performance of the photovoltaic modules.
The Millennial Acetic Acid Test Chamber adopts the box-in-box mode, which can conduct the acid resistance test on crystalline silicon solar cells and prevent the acetic acid failure of assembled modules. Application scenarios: regular monitoring of finished products in battery factories, evaluation of new pastes, and incoming material monitoring in module factories.

EVA Degree of Crosslinking Test System

Degree of cross-linking Test System is used to test materials such as EVA cross-linking, polyethylene (PE cross-linking,polyethylene insulated wire and cable (XLPE) cross-linking,natural polymer ion cross-linking and polymer crystallinity for photovoltaic module encapsulation. Test its flexibility, impact resistance, elasticity, optical transparency, low temperature bending, adhesion, environmental stress cracking resistance,weather resistance, chemical resistance, and heat sealing.

Junction Box Comprehensive Tester

The ME - 9960 junction box comprehensive tester is a dedicated testing instrument developed by our company to meet the testing requirements for the electrical characteristics of photovoltaic junction boxes. It can test parameters such as the forward conduction voltage drop VF, reverse leakage current IR, reverse voltage VR, on-state DC resistance R, and temperature TC of the diodes inside the junction box.
It can meet the testing requirements of junction boxes ranging from 10W to 400W (with 2 to 8 diodes). It is widely used in the on-line testing of junction box manufacturers and the incoming inspection of component users.
It complies with the photovoltaic standards IEC61215 and IEC61730. When used for testing photovoltaic module junction boxes, it can automatically identify the components under test and test multiple parameters of the junction box in one go.

Drop ball tester

The Millennial Drop Ball Tester adjusts a steel ball of a specified weight to a certain height and allows the steel ball to fall freely for the test. It impacts the surface of the test specimen and observes the degree of damage, which is used to determine the quality of plastics, ceramics, acrylics, glass fibers, photovoltaic modules, tempered glass and junction boxes.
The suction cup adopts the electromagnet mode, meeting the impact requirements specified in the standards GB/T9656, GB/T9962 and GB/T15763.2.

Semi-automatic scanning four-probe tester

The FPP300SA is a semi-automatic four-point probe sheet resistance tester designed for scientific research. It enables fast and precise testing of samples up to 450mm x 400mm, providing sheet resistance/resistivity information at different locations. The probe head incorporates precision mechanical clock movement technology, utilizing ruby bearings to guide tungsten carbide probes, ensuring high mechanical accuracy and extended durability. Industry-leading repeatability of 0.2% is achieved for standard resistor testing. With an ultra-wide measurement range of 1mΩ~100MΩ, it accommodates diverse applications across photovoltaic, semiconductor, alloy, ceramic, and other fields.

Stylus Profilometer

The Millennial Stylus Profilometer adopts contact - based surface topography measurement. It can measure the profiles of sample surfaces on scales ranging from micrometers to nanometers, and is capable of measuring step height, film thickness and thin - film height, surface topography, surface waviness, surface roughness, etc. It represents a new development in traditional surface topography measurement.
Stylus Profilometer adopts a new contact type surface topography measurement, with a minimum contact force of 1mg. There are no special requirements for the reflective properties, material type, and material hardness of the sample surface. It has a wide range of sample adaptability, high data reproducibility, and stable measurement. Convenient and efficient, it is a widely used measurement method.

Maximum Power Point Tracker

Millennial Maximum Power Point Tracker is a powerful and comprehensive multi-channel solar cell and component stability test system tailored for perovskite solar cell researchers. It uses a BBA-level LED solar simulator as an aging light source. It can control the temperature of the battery and the environmental atmosphere of the battery in a variety of ways (N2, dry air, constant temperature and humidity, etc.). It can perform long-term stability performancetests on multiple groups of batteries at the same time.
In addition to the traditional MPPT mode, it also adds constant voltage (such as open circuit voltage) and constant current aging (such as short circuit current) modes to increase the flexibility of stability research, and integrates powerful data analysis software to view and compare the performance indicators of different samples in real time.

Perovskite Glass Transmittance Tester

The online transmittance detection equipment for perovskite solar cells is a system that real - time monitors the optical transmittance of perovskite thin films, transparent oxide glass, or modules. It is used to optimize processes, ensure uniformity, and improve cell efficiency.

Perovskite P1 Laser Scribing Multifunctional Testing Machine

After the deposition of the transparent conductive electrode (TCO) and before the deposition of the hole - transport layer, a laser device will perform laser scribing on the sample to form independent strip - shaped conductive electrodes, which will serve as positioning points for subsequent P2 and P3 scribing. Therefore, by conducting quality inspections on P1 scribing, the efficiency, stability, uniformity, lifespan, safety, and manufacturing cost - effectiveness of perovskite solar cells can be improved in multiple aspects.
The Millennial Perovskite P1 Laser Scribing Multifunctional Testing Machine is a high - precision testing device specifically designed for the P1 laser scribing process of perovskite solar cells. The device can directly contact the sample through probes to test parameters such as resistance, accurately determining the quality of P1 scribing.

Perovskite Online PL Tester

Online PL defect detection addresses core challenges in solar cell production—speed, yield, cost, process optimization, and stability—through its non-contact, high-precision, and real-time feedback capabilities. Integrated with AI-driven deep learning, it enables fully automated defect identification and process optimization. This empowers customers to refine manufacturing parameters based on test results, enhancing device efficiency and stability.

Perovskite Online Sheet Resistance Tester

The online sheet resistance tester is a critical quality control device for perovskite solar cell production lines, designed to monitor the sheet resistance of materials such as transparent conductive layers in real time. Utilizing four-probe technology, it enables high-speed detection of thin-film conductivity uniformity, ensuring stable series resistance and fill factor, thereby enhancing the photovoltaic conversion efficiency of cells. The equipment seamlessly integrates into production lines, automatically feeds back data, and coordinates process adjustments (e.g., coating and annealing parameters), effectively reducing scrap rates and ensuring high yield and performance consistency in large-scale perovskite battery production.

Online Perovskite Film Thickness Tester

The online thickness measurement system utilizes spectroscopic ellipsometry principles. It analyzes alterations in the polarization state of linearly polarized light after reflection from thin-film samples. By measuring phase differences and amplitude ratios, film thickness is derived through model fitting. Featuring non-destructive testing capabilities, it preserves delicate film integrity while adapting to both wet-processing techniques (slot-die coating, inkjet printing) and vacuum deposition applications. Specifically designed for perovskite development, it enables crystallization process monitoring and large-area coating uniformity inspection, effectively minimizing photovoltaic efficiency variations.

Perovskite Process Inspection Workstation

The Perovskite Process Inspection Workstation integrates a Contact Angle Test Module, an Ellipsometer Test Module, a Sheet Resistance Test Module, and a Reflectance Test Module, facilitating users to conduct comprehensive evaluations of photovoltaic films. This all-in-one testing machine supports manual click/auto-switching of test modules. During testing, it enables single-point positioning mapping (supporting up to 5,000 points) and single-point multi-technique measurement (multifunctional testing for single points), maximizing one-stop service for customers.

Portable IV Curve Tester

This portable PV module power tester accurately measures the power output and IV curve of individual solar modules, while providing standardized power conversion efficiency under STC (Standard Test Conditions). The system features intuitive operation, high portability, and is equipped with a precision irradiance meter and temperature sensor.

Portable EL Tester

The portable EL tester is designed to detect hidden cracks inside solar panels, ensuring efficient power generation of photovoltaic modules. With a compact design, user-friendly operation, and high portability, it is ideally suited for mobile users requiring on-site inspections. This mobile testing tool is tailored for component inspection in solar power plants.

Portable Thermal Imaging Tester

This compact handheld infrared thermal imager is specifically designed for photovoltaic power plants to conduct temperature inspections on all electrical equipment. It helps identify potential faults, reduce maintenance costs, and ensure production safety.
Key features include one-handed operation for capturing images, a high-definition touchscreen display, and resistance to strong ambient light and laser interference.

Solar Module Multi-Channel Testing System

The outdoor module multi-channel testing system provides real-time synchronous multi-channel testing capabilities and supports customization of channel quantity and test module power according to specific user requirements. By networking multiple testers, it forms an evaluation system capable of simultaneously testing up to 300 photovoltaic (PV) modules, making it ideal for outdoor PV module performance comparison. The system enables comparative testing of multi-channel power generation efficiency, allowing side-by-side evaluation of IV characteristics and energy yield differences across different modules on the same time base. It also supports synchronous recording of multi-channel irradiance and temperature data, providing users with clear and intuitive test result analysis. This addresses the current need for real-world energy yield comparison testing of outdoor PV modules.
Additionally, the system features multi-channel/all-weather measurement output characteristics, automat

PV Inverter Power Quality Tester

The PV inverter power quality tester provides detailed recording and analysis of power quality parameters at photovoltaic power plant sites, including harmonics, voltage, current, frequency, voltage fluctuations, flicker, power, and three-phase unbalance. It also features advanced measurement functions such as power transient monitoring, waveform recording analysis, energy efficiency loss assessment, and inverter performance measurement, providing accurate data for managing grid-connected power quality in PV power plants. This equipment is characterized by high precision, wide frequency band, and broad measurement range.

Drone EL Tester

Designed for electroluminescence (EL) internal defect detection in PV power plant array components, this drone-based EL tester efficiently completes power plant quality inspection tasks. It supports switching between photo and video modes, facilitating third-party operation and maintenance (O&M) quality checks. Combined with fully automated focusing technology, the device enables flexible switching between multiple detection modes, making it the preferred tool for power plant inspection and O&M. Featuring long endurance, it is suitable for large-scale inspections, rapid mapping, high-definition imaging, and original data transmission.

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Sheet Resistance Testing Method - Four-probe Measurement Method

Date : 2024-01-25Views : 30

Many important parameters of device materials are related to resistivity. Today, with the rapid development of photovoltaic and semiconductor industry processes, the resistance uniformity and electrical properties of materials have received widespread attention. When characterizing materials, accurate resistivity is critical, as it determines how well the material conducts electricity. The four-point probe measurement method has been widely used in semiconductor measurement technology. The Four-Point Probe Tester developed by Millennial Solar has an ultra-wide measurement range and ultra-high measurement accuracy, and can characterize various materials. In this issue of Millennial Solar, you will learn about the measurement methods for characterizing sheet resistance in materials.

Sheet resistance

Sheet resistance refers to the resistance from one side of a square thin film of conductive material to the other side. One characteristic of sheet resistance is that the resistance from edge to edge of a square of any size is the same, and the sheet resistance between any distance is the same. In this way, the sheet resistance is only related to factors such as the thickness of the conductive film. Sheet resistance measurements are commonly used to characterize the uniformity of conductive or semiconductive coatings and materials for quality assurance purposes. Typical applications include semiconductors and solar cells, functional materials, amorphous alloys, LCD panels, etc.

So how is the square resistance tested?

Four-probe measurement method

The most important technique for measuring sheet resistance is the four-probe measurement method. The four probes are equally spaced and shown to be in contact with the surface. Current (I) is injected through probe 1 and collected through probe 4, while the voltage between probes 2 and 3 is measured. It works by applying a DC current (I) between two external probes and measuring the resulting voltage drop between the two internal probes.

Four point probe diagram

Four-Point Probe Tester

E-mail: market@millennialsolar.com

Four-Point Probe Tester is specially designed for scientific research. It can quickly and automatically scan samples up to 220mm to obtain sheet resistance/resistivity distribution information at different locations of the sample. Dynamic test repeatability (close to real scenarios) can reach 0.2%, which is an industry-leading level. The ultra-wide measurement range of 0.1μΩ~100MΩ can cover most application scenarios and can be widely used in many fields such as photovoltaics, semiconductors, alloys, and ceramics.

● Ultra-wide measurement range of 0.1μΩ~100MΩ

● It can calculate the average sheet resistance between positive and negative currents to eliminate possible voltage deviations and improve measurement accuracy.

● Two measurement methods: "manual arbitrary point measurement" and "fully automatic multi-point scanning", multiple preset schemes

● The probe pressure is adjustable from 3-5N to prevent the probe from puncturing the film while providing good electrical contact.

Four-Point Probe Tester can perform simple and direct resistance measurements, and provides a wide range of probe types to suit and optimize the characteristic characterization measurements of different surface materials, bringing a better measurement experience to users in more industries!

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