Modern Multi-frequency Metal Detectors are “No Fools” When It Comes to Dairy
A recently published article in What's New in Food Technology & Manufacturing magazine, Ensuring product quality and safety in the dairy industry, discussed how dairy product safety and quality can benefit from the use of inspection/detection equipment.
The article described how, historically, product inspection and detecting foreign objects in dairy products have been challenging.
The article described how, historically, product inspection and detecting foreign objects in dairy products have been challenging.
“Traditional metal detectors are often fooled by what is called a ‘product effect’ in cheese and other high-moisture, high-salt dairy products. These products have conductive properties that affect the magnetic field and trick the detector into generating a signal indicating metal is present when it is not.”
Before we start discussing the effect of product effect, here is a reminder that dairy covers many different types of products: milk, cheese, yogurt, ice cream, milk powders, whey protein concentrates, sauces, and other related items. In addition, there are different types of packaging for different types of dairy products — such as shelf-stable, biodegradable, metalized and transparent properties as well as variations in sizes from individual portions to large multipacks. So selecting the right checkweighing, metal detection and X-ray inspection technology depends on product attributes, materials, and packaging.
As I mentioned, product effect negatively impacts the metal detector's ability to distinguish between actual non-ferrous metal contaminants and the false signal given by the combination of typical product attributes. All metals, whether iron, stainless steel, brass or aluminum, react differently to an electromagnetic field, which is the principal underlying metal detection in products. These reactions change based on shape, size, orientation and position. The inspection process is further complicated by the varying densities, air bubbles and other physical characteristics of each dairy product, since no two are exactly the same. And we now add the challenge that moisture, salt and high mineral concentration can create a strong product specific signal that may mask detection of smaller signals generated by contaminant.
So, how can metal detector technology 'outfool' the dairy product effects?
A metal detector that utilizes multiple frequencies is now available. This newest multi-frequency metal detection technology, called multiscan scans a combination of up to four user selectable frequencies from 50 to 1000 kHz. This multiscan metal detector enables users to identify contaminants that are up to 70% smaller in volume than was previously detected on single and dual frequency detector technologies, reducing the probability of escaping detection to near zero. It is like having four metal detectors in one, to provide unmatched sensitivity and the highest probability of finding ferrous, non-ferrous, and stainless steel metal contaminants in challenging dairy applications with high product effect.
In applications where even multi-frequency metal detection is unable to meet the inspect requirements there are X-ray inspection systems that can not only help find foreign materials but can check for quality defects such as missing or broken components. Still confused? Don't be foolish. Contact our sales engineer to help ensure a quality dairy product gets into the hands of the consumer.
