Coin Ping Test Frequencies

When you tap a coin it rings at several resonant frequencies at once. This table lists three of them for each of the 40 coins Pingcoin supports: c0d2, c0d3 and c0d4. These are free-vibration modes of the coin disc with 2, 3 and 4 nodal diameters and 0 nodal circles.

Each frequency depends on the coin’s dimensions, density and elasticity, so a coin made of the wrong metal or to the wrong size rings differently. A match is evidence, not a guarantee. Real coins also vary slightly by year, wear and how they are measured, so expect readings close to these values rather than identical. For a full walkthrough see the silver coin ping test and gold coin ping test guides.