With the Bottom-Up Glass Inspection System, there is a new approach to temperature measurement in the production of low-emissivity (Low-E) glass. Low-E glass poses a major challenge for infrared devices, which traditionally measure the glass temperature from above when the panes move out of the furnace during production. The Bottom-Up Glass Inspection System solves this problem by installing two infrared imagers underneath the tempering line. These infrared imagers measure the temperature on the non-coated high-emissivity side of the glass in line scanning mode. An ultra-fast CTlaser 4M pyrometer, combined with the Digitally Controlled Lens Protection (DCLP) system, provides a reliable safeguard for both infrared cameras in case of glass breakage, ensuring continuous and accurate temperature monitoring.

Low-emissivity (Low-E) glass, commonly used for windows and facade components to enhance energy efficiency in buildings, poses significant challenges for traditional infrared (IR) devices. This type of glass is designed as multi-pane insulating glass with a coated side that has very low emissivity. Infrared devices traditionally measure the glass temperature from above as the panes exit the furnace. However, due to the low emissivity of the coated side, these devices often struggle to obtain accurate temperature readings, leading to inefficiencies and potential quality issues in the production process.

The Bottom-Up Glass Inspection System (GIS) from Optris introduces an innovative solution to this challenge. By installing multiple infrared imagers underneath the tempering line, the system can consistently measure the temperature on the non-coated, high-emissivity side of the glass. This approach ensures accurate temperature readings, which are crucial for maintaining the glass’s quality. Recent advancements in IR technology have facilitated the development of more compact, uncooled imagers suitable for this tight installation. Previously, such installations were not feasible with the bulky line scanners traditionally used in the industry above the production line. The compact design and small accessories of these new imagers allow for an innovative bottom-up package that significantly improves the accuracy and reliability of temperature measurements of glass.

The Optris infrared cameras, PI 450i G7 and PI 640i G7, are industry-specific models within the PI series, developed specifically for the glass industry. These cameras have a spectral response of 7.9 μm and a temperature range of 150 °C to 1500 °C. This wide temperature range allows their implementation in diverse applications within the production, refining, and further processing of glass panes.

The Bottom-Up Glass Inspection System (GIS) utilizes two VGA imagers with a maximum field of view of 111°, resulting in an impressive 1600-pixel scan line resolution over a maximum scan width of 4.3 m. Combining the two VGA imagers provides a high-resolution scan line across a significant width, ensuring detailed and accurate temperature data. This capability is essential for maintaining the quality and consistency of glass products, which are highly sensitive to temperature variations during production. The high resolution ensures precise temperature mapping across the entire width of the glass pane. In addition to determining the temperature distribution, the system can calculate the glass surface area, providing comprehensive data for process control and quality assurance.

The compact Bottom-Up system enables coating-independent measurement, ensuring continuous and accurate temperature readings regardless of the glass coating. This is critical for maintaining product quality across various applications. The system is equipped with an ultra-fast CTlaser 4M pyrometer, featuring a 90 μs exposure time, combined with a Digitally Controlled Lens Protection (DCLP) system. This combination provides a reliable safeguard for the infrared cameras in case of glass breakage, ensuring continuous operation and minimizing downtime.

Optris infrared cameras come with the license-free PIX Connect software, enabling the cameras to operate as line scan cameras. Traditional line scanners, used in the glass industry for various measurement procedures, are bulky, expensive, and require significant manual effort for setup. In contrast, the infrared camera system is compact, cost-effective, and easy to set up. The software allows for flexible positioning and dimensioning of the scan line, providing complete IR images for valuable additional information, especially during system setup.

Infrared cameras can accurately measure the surface temperatures of moving objects using minimal apertures, a function particularly significant in the glass industry. Glass temperature directly impacts its quality, so accurate temperature measurement at multiple points during the production process is critical. The data is transmitted directly to the process control system, enabling quick adjustments and ensuring optimal product quality.

The Bottom-Up Glass Inspection System (GIS) is a pre-assembled system that is easy to install on glass tempering furnaces. This turnkey solution simplifies the implementation process, allowing manufacturers to integrate the system into their existing production lines quickly. The system’s design ensures minimal disruption during installation while providing immediate benefits in terms of temperature measurement accuracy and process control.

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