Modern technology allows manufacturers to check for metals and other harmful objects within food packaging before it ever enters the grocery store. State-of-the-art food X-ray inspection systems can detect foreign objects with precision to ensure that food is safe for consumption. However, there are a number of factors that affect X-ray system sensitivity.
Learn about what can impact the accuracy of food X-ray systems, how manufacturers can work around these issues, and much more.
What Factors Can Affect X-Ray System Sensitivity?
Exactly how well can a food packaging X-ray system detect contaminants? Ultimately, these machines are quite effective at identifying high-density items like metals. Per federal regulations, food X-ray systems don’t use radioactive sources to generate images.
Instead, these systems use an X-ray tube that features a high voltage when in use, but emits no X-ray energy when the power is off. Employees and consumers are safe from radiation exposure or radiation sickness since this type of X-ray machine generates lower radiation doses than a dental X-ray. There is minimal external and internal exposure to radiation.
Although these machines perform accurately and safely the majority of the time, there are certain factors that impact their sensitivity.
X-Ray Energy Detector Resolution
The image that an X-ray machine produces needs the right resolution. Otherwise, it’s difficult to pinpoint contaminants. Images with larger pixels mean higher system sensitivity and higher-resolution images, whereas lower-resolution x-ray energy detectors that use smaller pixels require more power from the machine to spot objects accurately.
Conveyor Speed
Do you know the phrase “blink and you’ll miss it?” This is one of the factors that affect X-ray system sensitivity.
Machines lose their efficacy when the conveyor belt moves too fast. As a result, it’s harder to tell if there are shards of glass or metal within bulk packaging. The belt must move at a consistent pace to catch foreign objects, balancing production speed with the need to scan items accurately.
Product Characteristic
A food packaging plant that distributes cereals and meat will likely find differences in sensitivity between the two products. Meat, in particular, can trigger sensitivity since the x-ray machine can detect bones and inaccurately flag these as foreign contaminants, whereas cereals and snack foods likely won’t have this issue.
The packaging of the product also affects the X-ray system’s sensitivity. Products wrapped in thin plastic may generate different results than products with a glass or dense plastic case.
X-Ray Beam Geometry
The angle at which an X-ray beam hits the product impacts the machine’s sensitivity. A magnified beam that gets too close to the product can alter the findings, but a beam that is further away from the product may fail to identify hazards. Manufacturers must place the X-ray beam in the correct place for the conveyor belt and type of product.
Image Processing Algorithms
A food X-ray system relies on image processing algorithms to detect foreign components within the product. These artificial intelligence algorithms sort the image’s findings by their relevance. For example, researchers studying the density of food created an image-processing algorithm to relay the apparent density of various porous foods.
Can Environmental Factors Affect X-Ray System Sensitivity?
It’s not just mechanical and technological factors that affect X-ray system sensitivity. Understanding environmental factors is crucial for successful food inspections because, in most cases, technicians can control the environment.
Ambient Light
In ambient lighting, it’s easier to detect the contrast in an X-ray image. Technicians in charge of food inspection processes can adjust the type of lighting within the room to improve X-ray machine sensitivity.
Electrical Interference
Food packaging plants have lots of activity going on and plenty of electrical machines running simultaneously. A clashing amount of radio frequency and electromagnetic interference has adverse effects on a food inspection machine. The X-ray system will likely be more sensitive with more interference in the factory, which can lead to false detections.
Any machine that gives off electromagnetic energy should have the proper shielding around it to prevent disruptions.
Temperature and Humidity
The temperature of a room can greatly impact the way a food X-ray inspection system works. Manufacturers design these machines to work under certain conditions that are not extremely cold or humid.
For example, the XR Standard X-Ray Inspection system is reliable for scanning most packaged products, but only in an environment between 32 and 104 degrees Fahrenheit. The ideal humidity for this machine falls between 30 and 85%.
On the other hand, a product like the GP Bulk-Flow X-Ray Inspection system allows for more range. This product can function in temperatures ranging from 14 degrees to 104 degrees Fahrenheit and with up to 5% more humidity than the XR Standard Series.
How Can the Sensitivity of a Food System Be Optimized?
One of the best ways to optimize the sensitivity of a food X-ray system is to incorporate state-of-the-art imaging software. With customized algorithms, a plant can quickly determine any contaminants in food packages. Ensure proper training for those operating the machine so they understand compliance standards and can make necessary adjustments without compromising the line’s production.
Can the Type of Food Inspected Affect the Sensitivity of a Food X-Ray System?
In some cases, the type of food going through the machine is one of the factors that affect X-ray system sensitivity. However, this depends on the contaminant.
The machine may fail to detect contaminants in dense packaging. While certain packaged foods may cause more sensitivity loss than others, it’s not necessarily the food itself but the packaging or type of foreign object.
Foods like meat or fish may require higher machine sensitivity. These products contain natural bones, so any machine that cannot differentiate between a bone and a shard of plastic could cause a false rejection.
Certain TDI Packsys systems work well on all products, though specialty inspection systems are available to fit specific needs. Manufacturers can select machines that specifically handle meat, cheese, grains, nuts, and other food products.
Are There Any Limitations to the Sensitivity of Food X-Ray Systems?
A high-quality food X-ray system can detect contaminants including hard metals, plastic, glass, and animal bones. This technology can even pinpoint clumps of food flavoring or sugar within the package. However, these machines do have some limitations as to what they can pick up.
Products that have wood or paper in the packaging won’t have them show up in imaging. Other materials that can be difficult to detect are hair, insects, and thin, low-density plastics. Although X-ray systems can catch a lot during the inspection process, there is room for improvement given the existing limitations.
What Are the Recommended Maintenance and Cleaning Procedures to Optimize Sensitivity?
Maintaining an X-ray system is vital for maintaining its performance and avoiding cross-contamination. The best course of action is to perform preventative maintenance at least once a year. Check for fraying or damage to the conveyor belt, and inspect the safety switches and radiation shields.
Food product manufacturers should regularly take about five to ten packages and use real contaminants to test for the machine’s sensitivity as part of regular maintenance. Depending on what the machine picks up, manufacturers can adjust the internal components or recalibrate the system. Continue to run tests with contaminated samples to monitor the maintenance progress.
As for cleaning procedures, it’s crucial to clean the system’s air filter. These machines generate heat while in use and rely on their cooling fans to not overheat. If dirt or dust clogs the air filter, the system may not be able to cool down, which can result in costly damage to the X-ray machine.
How Does Calibration Impact the Sensitivity of X-Ray Systems?
TDI Packsys food x-ray machines have an automatic calibration function, so users don’t need to worry about scheduling a calibration service. It’s important to calibrate the machine on a regular basis to uphold performance quality and give accurate inspections. This service should also coincide with every new product that needs scanning so the machine can learn it and provide accurate imaging.
Calibration may make the machine more sensitive and prone to false rejections in the short term.
What Other Inspection Techniques Are Combined with X-Ray Systems to Improve Sensitivity in the Future?
Food X-ray machines can do a lot, but there’s still room for improvement. TDI Packsys also produces metal detectors to pinpoint any steel, iron, copper, or other harsh metals in food packaging. These industry-grade machines can pick up the slack when X-ray systems don’t detect certain metal contaminants.
Given all of the factors that affect X-ray system sensitivity, it’s important to keep your equipment clean and well-maintained. Ensure all safety standards are met so there’s no type of radiation emitting from the system, and test various products with a keen eye, especially if they come in dense packaging that the machine is less likely to see through. Reach out to TDI Packsys if you need any additional help with your food X-ray system.
