A new metal locator is described that is physically, rather than electrically, balanced. This eliminates some of the difficulties of using earlier equipment, which needs constant retuning. Because the new locator responds only to magnetic materials, it discriminates among foreign bodies, indicating those that can be extracted with a magnet. Of course, a metal locator should be used in conjunction with such other tools for management of an intraocular foreign body as roentgenograms and ultrasound.
Bronson NR, Turner FT. Practical Characteristics of Metal Locators. Arch Ophthalmol. 1972;88(2):199-203. doi:10.1001/archopht.1972.01000030201013