<P> Industrial metal detectors are used in the pharmaceutical, food, beverage, textile, garment, plastics, chemicals, lumber, mining, and packaging industries . </P> <P> Contamination of food by metal shards from broken processing machinery during the manufacturing process is a major safety issue in the food industry . Metal detectors for this purpose are widely used and integrated into the production line . </P> <P> Current practice at garment or apparel industry plants is to apply metal detecting after the garments are completely sewn and before garments are packed to check whether there is any metal contamination (needle, broken needle, etc .) in the garments . This needs to be done for safety reasons . </P> <P> The industrial metal detector was developed by Bruce Kerr and David Hiscock in 1947 . The founding company Goring Kerr pioneered the use and development of the first industrial metal detector . Mars Incorporated was one of the first customers of Goring Kerr using their Metlokate metal detector to inspect Mars bars . </P>

When were metal detectors first used in airports