Pulse induction metal detectors are poor discriminators. The SDC 2300 provides some level of discrimination only through audio. You must learn the pitch and volume of signals to determine what type of metal it is.
For example, the SDC 2300 will produce a high pitch and then low pitch tone for a ferrous target. For a non-ferrous target, it will produce a low pitch followed by a high pitch tone. Loud volume with short beeps will indicate a shallow target while quiet, longer tones will indicate a deep, large target. Intermittent beeps indicate a very shallow target or target that is on the surface.