The "large precious metal detector" you mentioned is also called a gold detector, because I am engaged in quality jewelry testing institutions, so I know this very well. If you choose a famous brand of precious metal detector, you can use it with confidence! As far as our detection is concerned, we use the Xifan EXF9600 precious metal detector, and the safety performance index meets the requirements of national standards (the light excitation source is MO target X-ray tube), which completely meets the most stringent radiation protection standards. This is what we have tested, because the power is only 200 watts, and the radiation is less than one-eighth of that of an induction cooker, which is the radiation of a mobile phone! Think about it, it can be said that it is absolutely safe and safe to operate!