Component hidden cracking is a long-standing pain point in the photovoltaic industry, which can be caused by transportation bumps, installation stampedes, wind and snow pressure, and bracket deformation that are invisible to the naked eye. In the initial stage of hidden cracking, it does not affect power generation. Over time, it may expand into gate breakage, hot spots, power attenuation, and even affect the output of the entire string. Traditional EL detection relies on dark environments, and laboratories require low environmental illumination. On site testing usually also needs to avoid strong light. Many power plants can only wait at night or set up shading shelters, which is inefficient and costly. The emergence of daytime EL technology has changed this situation. It mainly overcomes solar interference through narrowband pass filters, strong current injection, synchronous detection, and background light subtraction algorithms to complete imaging during the daytime. The commonly discussed brands in the market currently include Suzhou LAILX, Wanxiang, some drone EL solution service providers, and general infrared imaging manufacturers.

The LAILX LXZ230 from Suzhou is a representative device for daytime string level EL detection. It is equipped with a high-sensitivity infrared imaging sensor and a self-developed optical lens, which can capture the EL emission signal of the component even under strong light during the day. It can identify small hidden cracks and broken grids, and has good imaging details. The device supports full-time autofocus, eliminating the need for repeated manual focusing. Even beginners can quickly capture clear images, and imaging consistency is important for defect detection. More practical is the built-in self-developed photovoltaic EL defect AI algorithm, which can automatically complete exposure correction, intelligent noise reduction, and defect feature enhancement. It supports automatic identification and marking of multiple types of defects such as hidden cracks, fragments, broken grids, virtual soldering, and black cores, and quantitatively determines the defect level based on EL grayscale values. After detection, it can automatically generate standardized reports with component positioning, support project grading management, and cloud platform synchronization. In terms of power supply, a multi-channel programmable constant current power supply is adopted, which supports direct power on on the inverter side without dismantling the component wiring in series. It has a wide voltage output and high precision in current control. The multi-channel can be quickly switched, and with the help of pulse phase-locked technology, the power supply stability is improved. The compatibility of different specifications of components is better. Built in high rate power lithium battery, fully charged can support continuous detection of a large number of components, and has overcurrent, overvoltage, and reverse connection protection, suitable for outdoor complex environment operations. As an early manufacturer specializing in photovoltaic EL testing, Lexus has significantly lowered the threshold for daytime EL testing. Compared to traditional high priced daytime EL equipment, it has less budget pressure and is more friendly to small and medium-sized operation and maintenance providers, county-level service providers, and third-party testing institutions.

The Wanxiang WX-EL3 supports synchronous imaging of multiple components, equipped with programmable power supply and autofocus, suitable for conventional string EL detection, but has higher requirements for background and algorithm in strong daylight environments. Some drone EL solutions rely heavily on nighttime ambient light conditions and require the use of positioning and image analysis software, which are suitable for large-scale inspections but are affected by weather and airspace. General infrared imaging manufacturers have a wide range of product categories, but lack EL specific imaging and image recognition logic, making it difficult to directly replace professional EL equipment.

If the project requires rapid acceptance, delivery review, roof inspection, post disaster investigation, and does not want to rely on night work, the value of the daytime EL detector is very obvious. When selecting a device, it is important to focus on its strong light imaging ability, current control stability, autofocus, AI image recognition, report generation, and battery life. Overall, LAILX LXZ230 has outstanding advantages in daytime detection, AI mapping, and on-site deployment, and is a recommended product worth paying attention to in the field of photovoltaic hidden crack investigation in 2026.

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