A face-to-face interview with an x-ray inspection expert, George Humphries, to answer the most common x-ray product inspection questions. George has over 20 years’ experience in the industry and has been a technical specialist for Eagle Product Inspection for the past 11 years. We had a moment to sit with him and get the answers you all want to know regarding x-ray product inspection and its detection capabilities.
Q. Is x-ray equipment for food inspection safe?
Yes x-ray equipment for food inspection is safe. Machines do not carry radiation sources. X-rays are generated in the machine by shooting electrons at a Tungsten target that generates x-rays. When the x-ray is off, there is no radiation present. Our new infographic illustrates some interesting x-ray safety facts.
Q. What can an x-ray system detect?
X-ray inspection systems can detect objects that are denser than water. The general rule is if it floats on water, it is less dense than water. For example, an x-ray system can find hollow hearts in potatoes because they are less dense than the surrounding potato. Therefore, generally contaminants such as bugs, wood or plastic cannot be detected. There is a lot of variability with plastic. Plastics which are embedded with barium are detectable, pure plastic cannot be seen.
X-ray inspection systems can detect all types of granite and ceramic stone because it is denser than water. There are many types of stones with varying sizes, it all depends on the density of their surrounding products for accurate detection. X-ray equipment for food inspection can detect ferrous and non-ferrous metal because their density does not vary much in comparison to stainless steel. Aluminum can also be detected depending on its size as it is less dense versus other metals. It can also detect calcium in bone and therefore detects bone. Calcium build-up occurs immediately at time of death. The calcium seen as whiteness in a bone is what x-ray equipment detects.
Q. Can an x-ray machine weigh product?
Yes, an x-ray can weigh products, but x-ray machines do not have a load cell, it is not a checkweigher. X-ray inspection systems weigh by ‘teaching’ the density of the product to a weight algorithm. This algorithm converts product density to a weight value.
Q. Can x-ray detect fill level?
Yes x-ray product inspection can check the head space or fill level which is used as a gauge after sealing products such as canned goods, yogurts or ready meals.
Q. Can an x-ray system count products or objects within a product?
Yes an x-ray system for food inspection can count products, as long as what needs to be counted is denser than the surrounding products. For example, in a cherry pie x-ray could guarantee that there are five cherries on top. It can also count whether there is product in divisions within packaging. If a package has 12 divisions in it and you want to ensure that there is product within every single pocket it can verify that.
Q. How accurate is an x-ray inspection system?
X-ray product inspection has a 95% probability of detection also known as POD.
Q. Can an x-ray machine for food inspection check package integrity?
That would depend on the package. Many food manufacturers want to look into a seam of the pouch and if your product has a lot of salt in it, x-ray can detect it easily. However, if your product is watery without much salt or spice, then checking seal integrity would be difficult. If dense food product gets trapped in the seal, then this can be detected but it all depends on the product.
Q. Can x-ray inspection systems see if a package is open or closed?
X-ray in rigid applications with jars on a conveyor can verify if a lid is present. On boxed products it all depends on the package. For non-rigid packaging such as foil or plastic bags the x-rays will not be useful to check for open or closed packages.
If you would like to learn the basics of how x-ray inspection systems work, please visit this blog – X-ray 101 for more information.