The Surface and Size settings in relation to circuits designed according to the principles of low frequency or multi frequency radar are used to determine the size of the target surface and the size of the target surface can also be adjusted in the Surface and Size Threshold and by determining the Surface and Size Threshold settings it can be measured The target level is determined and for the main work scene for diamagnetic metals such as gold and silver most of the time the highest Threshold number of Surface and Size is used on 45 because this category of diamagnetic metals such as gold and silver which in the main work scene and life After that the field itself has moved around and it is one of the factors that causes this group of targets with a large surface area to have a return field in the main work scene and for this reason the Surface and Size settings such as the Threshold of the Surface and Size on the highest number of 45 is used