Bottom-Up GIS 640i G7

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 (302 °F to 2732 °F). 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 (14 ft). 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.

Thermography software optris PIX Connect is included and license-free. All infrared cameras are delivered with the thermography software optris PIX Connect, developed specifically for the extensive documentation and analysis of thermal images.
The Windows-based PIX Connect software enables users to tailor the infrared cameras to meet specific requirements. It analyses live and recorded temperature data and triggers alarm signals for process integration.The key to leveraging the Optris infrared camera is a correct configuration. This includes detailed device-specific configurations such as frame rate, measurement range adjustments, external communication settings, and USB/Ethernet configurations. Moreover, PIX Connect facilitates firmware updates and the download of configuration files over the Internet. PIX Connect Optris offers several different SDKs for our Xi and PI thermal imaging cameras.
Depending on the operating platform, the infrared camera, the coding language, and the hardware platform, different software interfaces can be utilized:
SDK

How do I install the system?

The Bottom-Up GIS is a pre-assembled system designed for straightforward installation on glass tempering furnaces. Optris or distributors are available to handle the installation and monitoring during the commissioning phase, ensuring a smooth process. For the first commissioning of the entire system, all components must be correctly positioned. Since all components are already pre-wired, they must only be brought into the correct position. The camera must be focused. After connecting the hardware, the configuration in the PIX Connect software can be done.

Where do I install the system?

A suitable position for glass measurement is between the furnace and the immediately following annealing furnace. In most cases, there is a small slit there, as the glass is transported on the glass is transported on conveyor belts, allowing a contactless temperature measurement. After leaving the furnace, the glass must be cooled down relatively quickly. The annealing furnace follows the heating furnace at a very short distance.

What is the package containing?

The whole system consists of three main components: two infrared cameras with shutters, an additional pyrometer that detects broken glass approaching the infrared cameras, and a switch cabinet with a complete electronic unit and control unit.

Do I need a computer?

Yes, Optris recommends a Windows OS Windows 10 or higher with 16GB RAM and an i7 processor.

Shall an input signal to trigger recordings be integrated?

It is recommended to start triggering the line scan of the system with an additional input. Therefore, the cabinet must opened to integrate the furnace’s input signal with the glass inspection system.

What kind of maintenance should be carried out?

The system requires a maintenance check at regular intervals. Here, it should be checked whether the camera’s optics are clean and correctly focused and whether the shutter systems still function properly. This includes a complete opening and closing of the shutters. These points must be observed, as they directly influence the temperature measurement. Never use cleaning compounds containing solvents (neither for the lens nor the housing). The lens surface can be cleaned with a soft, humid tissue (moistened with water) or a lens cleaner.

Does the temperature reading depend on the measurement angle?

Angle dependence is another important factor to consider when measuring temperature. On the uncoated side, the values are constant up to an angle of 45 . On the coated side (Low-E), the 60 optics is preferred since the influence of the emissivity change is negligiblehere.

Why should I measure glass with a G7 infrared camera?

Accurate temperature measurement relies significantly on the emissivity of glass, a crucial determinant affected by multiple factors and tailored to specific applications. The narrowband G7 spectral range, peaking at 7.9 µm, aligns with the highest emissivity of glass, facilitating remote temperature measurement by minimizing issues related to reflectivity and transmissivity. Additionally, within this wavelength range, the angle dependency of glass surface emissivity is reduced, enabling temperature measurement irrespective of reflection, even at inclined viewing angles.

How do I align the camera?

The G7 infrared camera offers a sighting mode in which an infrared image is shown, but no temperature values are measured.

• 2x PI 640i infrared cameras
• 2x Industrial Process Interface
• CTlaser 4ML glass breakage sensor with USB interface
• 2x DCLP Shutter system with mounting brackets for imagers
• 2x USB Server Gigabit
• Control cabinet with cable set (10 m / 32.8 ft each) and remote control box
• Software package
• 100-230 V AC/ 24 V DC power supply for initial start-up