What is a X-ray foreign object detector and how does it working?
An X-ray foreign object detector is a non-destructive inspection device that uses X-ray technology to identify contaminants, foreign bodies, or defects within products, materials, or packaging. It is widely used in industries such as food processing, pharmaceuticals, garment factory and manufacturing to ensure product safety, quality control, and compliance with regulatory standards.Common foreign objects it can detect include metal fragments, glass shards, stones, plastic pieces, bones, and even some low-density contaminants depending on the systeom' sensitivity.
The operation of an X-ray foreign object detector relies on the differentialabsorption of X-rays by different materials.
1. X-ray Generation: The detector is equipped with an X-ray tube that emits acontrolled beam of X-rays when energized. X-rays are a form of high-energyelectromagnetic radiation with strong penetrating power.
2. Product Conveyance: The inspected product moves through the X-rayinspection chamber via a conveyor belt. The system is calibrated to ensurethe product passes through the X-ray beam at a steady speed.
3. X-ray Penetration and Absorption: As X-rays pass through the product,different materials absorb X-rays to varying degrees:
Dense materials such as metals, glass, and bones absorb more X-rays,blocking most of the radiation from reaching the detector on the otherside.
Low-density materials like food, plastic, or cardboard allow more X-raysto pass through.
4. Image Capture and Processing: A high-resolution X-ray detector array(such as a scintillator coupled with a CCD/CMOS sensor) captures the X-raysthat pass through the product, converting them into a grayscale digitalimage. In this image:
Areas where more X-rays are absorbed appear darker.
Areas with higher X-ray transmission appear lighter.
Foreign objects stand out as distinct dark spots or irregular shapesagainst the background of the product.
5. Analysis and Decision-Making: The system's software analyzes the digital image in real time. It uses pre-set algorithms and calibration parameters to distinguish normal product features from potential foreign contaminants. If a foreign object is detected:
The system triggers an alarm (visual or audible).
It can automatically reject the contaminated product by activating a reject mechanism (e.g., a puff of air, a push arm, or a diverting gate) to remove it from the production line.
Inspection data and images are usually logged for traceability and quality management purposes.
What can be detected?
Metallic contaminants：Iron，copper，aluminum， stainless steel.
Glass contaminants: glass shards，glass beads.
Ceramic and stone contaminants: ceramic chip，stones，shells.
Plastic and rubber contaminants: hard plastics，rubber particles.
Bone and hard contaminants: bone fragments.