Abstract: A coin validation system includes a coin runway (1), a coil (2) positioned adjacent to the runway and a resonant circuit (4) coupled to the coil (2). A first signal monitoring circuit (6,8,12) is arranged to monitor oscillating signals generated in the resonant circuit (4) as the coin moves down the runway. The system further includes another coil (3). The other coil (3) is displaced with respect to the one coil (2) in the direction of movement of the coin (6) down the runway (1). Another resonant circuit (5) is coupled to the other coil (3) and a second signal monitoring circuit (7,8,11) are arranged to monitor the oscillating signals generated in the other resonant circuit (5). The signal monitoring circuits (6,7,8,11,12) are arranged to compare the signals in the resonant circuits (4,5) and to determine from a measured signal parameter a measurement which is representative of the coin (6) and which is velocity and acceleration independent.