The gravity falling metal detector can indeed be used to detect various types of materials, including powders, bulk materials, and sheet-like items. This type of metal detector is typically installed in free-falling environments such as drop chutes, at the bottom of multi-head scales, and at the feed inlet of vertical packaging machines to perform metal detection during the free-fall process of the materials. When a metal object passes through the detector, it emits an audible or visual signal to prompt the operator for further action. This type of metal detector typically requires high precision and sensitivity to detect even the smallest metal objects.