metal detectors are standard foreign object detection technology in food processing facilities, but they are not without limitations. Its no simple task to determine which frequency is the best for metal detection and plant noise and product effect can still make it difficult to ascertain contaminant signals.  The technology has certainly evolved over the years, but not quickly enough to keep pace with more stringent regulations and retailer codes of practice requirements. There are also greater productivity demands. All have exposed the shortcomings of traditional metal detection technology and motivated food processors to seek out new solutions that ensure a higher level of consumer safety.

The negative impacts of a product recall are also top of mind for food processors. Not only are recalls incredibly costly, but they can also shake consumer trust in the brand and individual products. News outlets are quick to report on these incidents and consumers actively voice their concerns and disdain on social media, all of which can exacerbate an already difficult situation. In some cases, damage to reputation and associated business losses can be irreparable.

Given whats at stake in todays environment of greater scrutiny, a more sophisticated contaminant detection approach is critically needed.

metal Detection Challenges

Food processors know that background noise can interfere with signals from standard metal detectors, and product effect can lead to false positives when a wet product is incorrectly identified as metal. These common occurrences can trigger false rejects and slow down production. Historically, food processors could do very little to solve for these issues, as noise is generally unavoidable in a food processing plant. There are large motors turning on and off, vibrating production equipment and many food products are wet and contain salt which makes them conductive.

Food processors also grapple with selecing the appropriate frequency for their metal detectors. It’s widely understood that ferrous is the easiest metal to detect, due to its magnetic properties, but stainless steel contains only a small amount of ferrous metal and has little to no magnetic property. To find stainless steel with a metal detector, a higher frequency is needed.

A logical solution would be to opt for a metal detector which can run both a low frequency (for ferrous metal) and one high frequency (for stainless steel and others with little magnetic property), but its not that simple. metal size, as well as the shape, orientation and position of the metal can change the resulting signals in a metal detector, adding complexity to frequency optimisation. Ultimately, the "best" frequency for any metal detection application is as many as possible, and all at once.

A New Approach: Multiscan metal Detection

Fortunately, new technology can help food processors overcome the limitations of traditional metal detectors. One such solution, the Thermo Scientific Sentinel Multiscan metal Detector can scan up to five user-selectable frequencies at once, providing unmatched sensitivity and offering the highest probability of finding ferrous, non-ferrous and stainless-steel metal contaminants in even the most challenging applications such as dairy, meat, poultry, bread and other foods with high product effect. More compact models of the technology are also available that integrate the metal detector with selec Thermo Scientific checkweighers on the same conveyor to reduce the total manufacturing footprint. These value-packed combo units also have harmonised communications between the metal detector and checkweigher for ease of use.

With multiscan technology, users can pick a set of up to five frequencies, from 50 kHz to 1000 kHz, which switch sequentially at an extremely high rate (thousands of times while a product is in the metal detector aperture). The effect is a single metal detector that has the power of five. Food processers benefit from the ability to run at a frequency that is more likely to detect the most common metals they may encounter. Probability of detection increases exponentially, and escapes are far less likely. With multiscan technology, users can identify contaminants that are up to 50 percent smaller in volume compared to simple single frequency detectors.

Enhancing Food Safety

Consumer safety is critically important to food processers, regardless of whether they sell directly to consumers or work with retailers. The food processing marketplace is highly competitive, and few can afford any misstep related to consumer safety. The number and diversity of food recalls on the US Food & Drug Administrations recall webpage shows how prevalent the problem is, and consumers are taking notice. For many processors, inspection technology can be their most vital line of defence against costly recall and, even worse, having contaminated product bearing their brand name reach a consumer.

Until multiscan metal detection, single or dual simultaneous frequency metal detectors came with compromises and an increased risk of escape. This is no longer the case. This new, innovative technology enables five times the protection with unprecedented, almost unlimited, flexibility. Within the fast-paced and complex processing environment, it can seem nearly impossible to control every possible point of contamination. With multiscan deployed, however, you can be confident that youre bringing the most advanced technology to bear for risk mitigation, brand protection and consumer safety.