Pyle PHMD1 Instruction Manual page 8

 Let other nonferrous metals approach the search coil, the meter pointer will
deflect to the right, and the sound will turn louder. (Figure.12)
6. Discriminate silver
 Set the "DISC" knob to "MAX". Adjust the balance to let the meter pointer
points "0"and the detector sound a light hum tone.
 Let the 25￠silver coin approach the search coil slowly, the meter pointer will
deflect to the right, and the sound will turn loud. (Figure.13)
 Let other metal samples approach the search coil slowly, the meter pointer will
deflect to the left, and the sound will turn light. (Figure.14)
Figure.12
Figure.13
8