Metal shield, bell

Coin Let's start with the fact that under the coin in the descriptions of many foreign devices usually means a coin with a diameter 25 (mm). For those who still remember - this is the coin of the USSR in denominations of 5 cents. Depth of detection of this coin is 10 (cm) for appliances up to a paltry 50 (cm) to very serious. Detection depth depends strongly on the size of the sensor (typically - the diameter of the disc with coils). Roughly, for a coin detection depth is approximately equal to the diameter of the sensor. The smaller coins will be found at shorter distances. For example, the detection depth coins of 1 penny will be approximately two times less than described above for a nickle. detecteur de metaux occasion