NDT of food,
packaging and heat exchangers

Test systems and equipment for food inspection and packaging testing

Food must always be flawless in terms of quality and freshness. In order to ensure this basic requirement of the food industry, edevis offers various non-destructive thermographic testing systems and devices that are used in the following areas:

  1. The determination of food properties such as density or water content.
  2. The inline inspection for freshness, rottenness or deterioration, such as pressure marks.
  3. The leak test of the packaging, such as sealing seams.
  4. Thermal process control in production, such as the cooling of beer.
  5. Testing of parts that come into contact with food, e.g. heat exchanger testing for cracks and leaks.

Our test procedures are non-destructive, can be automated inline and can also be equipped for special hygiene requirements.

Food industry NDT in a nutshell

edevis has a high level of expertise in imaging thermography testing systems for the food industry. For many years we have been working in close cooperation with the Department of Biosystems at the Catholic University of Leuven, Belgium. The advantages: Food products are products that can have a high variance within them. With our imaging thermography methods, we can get a grip on interfering variables or scattering and measure more reliably. And: our methods are not only non-destructive, but also non-contact, i.e. they do not require contamination, auxiliary materials or foreign media – and can perform inline inspections in no time at all. We offer savings potential through automation and technology that recognises everything and allows highly automated processing at high inspection speeds.  

edevis thermographic testing technology in detail

With our thermography methods, we can precisely determine physical properties of foods such as the water content of a melon variety or the density of beverages. Manufacturers of nut chocolates can use edevis testing equipment to find out which nuts are the best. Rotten nuts can be sorted out in a fraction of a second during production via the heat flow – they have too low a heat capacity. In a similar way, the ageing state or degree of freshness of foods can be determined, such as eggs. Thermography can see inside food without having to open it.The size of the cavity in the egg correlates with the quality of the egg – the more protein is missing, the larger the cavity and the poorer the quality.

Especially in the case of fruits or vegetables, measuring their infrared spectral properties can guarantee the flawlessness of food: for example, you can wonderfully detect the bruises in apples or tomatoes via infrared, in the wavelength range between 1 and 3 micrometres, even before the human eye would see them. For tomatoes with long transport routes, quality and cost advantages can be tapped in this way.

Another mainstay of edevis is the leak testing of packaging. Especially in the case of products with a long shelf life, sealed seams of packaging can become a problem in the medium term, for example in the case of an army’s ration packs. But our methods also prove their worth with the simple yoghurt lid of a dairy. Thermography also has an advantage when it comes to testing bottle caps for leaks: in contrast to a gas test, for example, thermography does not require a foreign medium and thus does not require an additional “time eater” that only inflates the cycle time and causes unnecessary consumption.

A very important topic for the maintenance area of the food industry is heat exchanger testing. These must be suitable for foodstuffs and therefore must not show any cracks. Currently, visual inspection or dye penetrant testing is used more poorly than not. This crack inspection of heat exchangers can be done much better, faster, cleaner and 100 % reliably documented with non-contact induction thermography.

Let’s now move on to process control of temperatures in food production: is the wine cool enough for fermentation, does the food have the right target temperature for further processing, is the mould for the chocolate hot enough? The answers to these questions are actually the be-all and end-all for food production, but they are not always solved 100 % state of the art technically so far. Foodstuffs are organic products whose inner life can show variance; moreover, variances can also occur in the processing and production process. If you measure with a temperature sensor at one point in the vat, there is no guarantee that this measured value applies to the entire vat. Currently, the error rates here are clearly too high because the measurements are not taken or are too close to the point. If a drop of water runs down a beer keg, theoretically only the temperature of the drop could be measured, but not that of the keg behind it! This cannot happen with thermographic inspection systems from edevis: They measure the barrel as a whole or the entire interior of the vat and can reliably detect temperature variations. This enables full process control down to the last detail. For example, with liquid chocolate on a butter biscuit: Checking that the “blob” is the perfect dosage, size and consistency is one of those classic challenges for which our thermographic inspection systems are perfectly adapted. Where would you like to realise more process reliability in your food production? Talk to us.