Development of three channel SQUIDs contaminant detector for food inspection

Mixture of metallic contaminants to food is serious problems not only for consumers but manufactures. To ensure the food safety, finding small metallic contaminants is important. A metal contaminant may come from a machine in the process of food and it contaminates food. Finding small metallic contaminants is important for food safety. Food manufactures are installing inspection systems such as eddy current detectors and X-ray imaging. The eddy current metal detector is widely used in a food factory. However, the sensitivity (threshold level) is not stable and is highly influenced by the conductivity of the material. The X-ray imaging is a useful technique and is getting popular in food factories and other industries. However, the lower detection limit for practical X-ray usage is in the order of 1 mm. Moreover, X-ray radiation sometimes causes ionization of the food, which may often change a taste of the food.