How to Make Metal Detector

Metal detectors come in a variety of forms but generally rely on the basic primary components. An oscillator sends an alternating current through a coil of electrical wire which creates an alternating magnetic field. A metal object will disrupt this magnetic field if it comes close enough to the metal detector's coil. The metal detector then detects this disruption and provides an audible signal to the operator. You can demonstrate this concept by making a simple metal detector from common household items.

Things You'll Need

• CD case
• Scissors
• Velcro
• AM radio (pocket-sized)
• Calculator (solar-powered)
• Quarter

Instructions

1. Remove the plastic insert from the inside of the CD case. Cut a piece of Velcro that will fit a flat section on the back of radio. Cut another piece of Velcro to fit the back of the calculator.

2. Attach the matching loop pieces of Velcro to the backs of the radio and calculator. Place the corresponding hook pieces on to the interior sides of the CD cover.

3. Mount the radio and calculator to the CD case using the appropriate pieces of Velcro. Turn the radio and calculator on and turn the volume up on the radio. Set the radio to AM and tune it to the highest AM frequency that isn't receiving a signal. You should hear only loud static.

4. Bring the radio and calculator closer together by slowly folding the CD case closed. Stop folding the CD case when you hear a tone from the radio. This tone is an electromagnetic signal from the calculator that's being detected by the radio. Open the CD case slowly until you barely hear the tone on the radio. Note the angle of the CD case.

5. Keep the CD case open at the angle you established in step 4. Move the CD case toward the quarter until you hear a loud tone. Note the distance of the CD case from the quarter to determine your metal detector's detection distance.

References

• Downtown Club

Resources

• Read this Article in Spanish