Key Slip Ring Technology Behind Baggage Screening Systems

Airport security is one of the concerns in a time when the airways are part and parcel of international connectivity. The U.S. Department of Homeland Security estimates that more than 4.5 billion passengers travel globally each year, and all forms of travel safety rely on the latest technologies for protection. Computed Tomography (CT) scanners and X-ray machines that are used to screen bags are among the latest equipment in airport safety and security. The baggage screening slip ring is a teeny tiny aspect of these complex networks and is the most essential part.

At the heart of this growth lies sophisticated slip ring technology that enables the continuous rotation and data transmission capabilities essential for modern security screening.

Why Slip Rings Are Essential in Baggage Screening Systems 

A slip ring, rotary electrical joint, or rotating electrical connector, is an electromechanical device that transfers the power and electrical signal (communication) between a stationary structure and a rotating structure. With regard to the slip rings in the airport CT scanners, they are very useful in the fact that they will make it very possible to have the continuous rotation that happens on the CT-based baggage screening systems.

● Rotation Specification: The scanning assembly (gantry) needs to rotation in a smooth and high-velocity manner to acquire high resolution images.

● Power and Data Mover: This rotating assembly needs a persistent source of high-voltage to charge the X-ray tube and complex, high data rate data transfer between the detectors and the processing computers.

● Constant Use: the screening of thousands of bags on a daily basis requires constant and dependable rotation without cable tangling.

Enter the slip ring (or rotating electrical joint). It acts as the electro-mechanical bridge between the stationary base of the scanner and its rotating gantry. Its core function is to transmit:

● Electrical Power: Runs electrical power at high-voltage to the X-ray tube and at lower voltages to the detectors, sensors, and to monitor when rotating.

● Data Signals: High-speed digital data streams (often Gigabit Ethernet or faster) from the detectors capturing X-ray attenuation data. This includes complex image data crucial for CT reconstruction.

● Control Signals: Motor, sensor and other element commands in the rotating side.

Note: A slip ring would be necessary otherwise cables would hang up, break or drastically restrict rotational movement, making today high-throughput, multiple-angle baggage screening current in terms of both performance and quantity impossible. These are the key enabler of the constant 360-degree scanning key to CT baggage scanning technologies and highly progressive X-ray systems.

Key Slip Ring Technologies for Baggage Scanners 

The demands of baggage screening systems have driven the development of various slip ring technologies, each tailored to specific requirements. Below, we explore the primary types of CT baggage scanning technology slip rings used in these applications:

—Accuracy Multi-Channel Electrical Connections：

Accuracy multi-channel electrical connector require quality precision that is made of precious metals, which include silver alloys ( silver - silver  or  copper-graphite connectors) because of low electrical noise, minimal voltage drop, high current-carrying capacity (for the X-ray tube) and high wear resistance.

—High-Speed Data Transmission Modules：

In baggage screening slip rings, an increasing number of systems are integrating wireless high-speed data transmission modules. Wireless transmission handles the large bandwidth required by modern CT detectors while avoiding electromagnetic interference (EMI), making the high-resolution 3D imaging demanded by airport CT scanners possible — and this is precisely why slip rings remain indispensable.

—EMI/RFI Shielding：

Thorough shielding can ensure that no electrical noise generated by the slip ring itself is likely to interfere with sensitive detector signals or other airport electronics, and can guard against outside noise.

—Modularity & Serviceability：

Many designs are modular, with most wear items (e.g. brush block) or data modules being user replaceable, further reducing expensive downtime during the baggage inspection system.

Application in Baggage Screening System Types 

CT-based baggage screening systems are advanced due to their ability to generate 3D images, relying heavily on baggage screening slip rings, unlike traditional X-ray machines.

CT Scanners for Carry-On Baggage：

Carry-on baggage scanners, like the Smiths Detection HI-SCAN 6040 CTiX, utilize slip rings for rapid rotation and high data transmission, enabling the scanning of liquids and electronics without removing bags.

CT Scanners for Checked Baggage：

The scanners of checked baggage are larger and scan more luggage at a time. The Analogic SeleCT is one. This scanner is to be left running continuously, and it should deal with large luggage. Since the CT tunnel is broader, the slip rings in it should also be broader.

Non-CT Systems：

Do Not Use No Slip Rings Conventional X-ray baggage scanning machines are not rotational. They do not utilise slip rings. However, several airports are instead putting in place CT scanners. The EU will demand all airports to have a CT scanner installed by 2026 and, thus, we are likely to see an increase in slip ring applications of such equipment.

Advantages of Using High-Quality Slip Rings 

Investing in high-quality security scanner slip rings offers significant benefits for baggage screening systems, enhancing both operational efficiency and security outcomes. Key advantages include:

● Reliability and Durability: High-quality slip rings are engineered to withstand continuous use in demanding environments, reducing the risk of system failures that could disrupt airport operations.

● Enhanced Data Transmission: Advanced slip rings, particularly contactless models, support high-speed data transfer, ensuring clear and accurate 3D images for precise threat detection.

● Reduced Maintenance: Contactless technologies eliminate the need for frequent brush replacements, lowering maintenance costs and minimizing downtime.

● Improved Image Quality: By maintaining consistent power and signal transmission, high-quality slip rings reduce image artifacts, enhancing the scanner’s ability to identify prohibited items.

● Compliance with Standards: Reliable slip rings help scanners meet regulatory requirements, such as ECAC EDS Standard 3, ensuring compliance with global security protocols.

These benefits translate into shorter wait times for passengers, reduced operational costs for airports, and enhanced safety through more accurate threat detection.

Conclusion: A Small Component with a Big Role

Despite their small size, slip rings for baggage inspection play a monumental role in the functionality of CT-based baggage screening systems. By enabling continuous rotation and reliable data transmission, they ensure that airports can process luggage quickly and accurately, maintaining high security standards. As technology evolves, innovations in slip ring design, such as contactless transmission and larger diameters, are poised to further enhance the efficiency and effectiveness of airport security.

For airport operators, security agencies, and equipment manufacturers, understanding the importance of slip rings in airport security is crucial. Investing in high-quality slip rings not only improves system performance but also contributes to a safer and more seamless travel experience. As the aviation industry continues to grow, the humble slip ring will remain a vital component in safeguarding the skies.