Abstract: In order to check whether the coin (2) has the impress design of an acceptable coin, the coin surface is scanned along a track (10) by an inductive probe (5), thus producing a signal which corresponds to the depth of the impression along the track (10). The relative movement of the probe (5), which is needed for scanning, in relation to the coin (2) is obtained as the coin (2) rolls past the probe (5). A memory stores, as comparison signals, signals obtained at mutually displaced tracks (10, 11) of the obverse side and reverse side of each acceptable coin. These signals are obtained as each coin to be verified rolls past the probe (5) from various starting positions. The verification signal received from the coin to be checked is compared with each of the stored comparison signals. If one of these comparisons results in coincidence within specific limits, then a coincidence signal is transmitted.

Abstract: The coin to be checked for several characteristics influences, partially in succession and partially simultaneously, the coils (7-12) of several oscillator tank circuits (1-6). The oscillator tank circuits (1-6) are correspondingly connected to an amplifier (14) for the formation of an oscillator, individually in succession, those circuits with simultaneously influenced coils being connected periodically in alternation to this amplifier. Thereby, successive and simultaneous, high-frequency test signals are produced which are nested in one another in accordance with the time-division multiplex principle, these test signals corresponding to the influences exerted by the coin on the oscillator tank circuit coils (7-12). These test signals, after demodulation (19) and analog-to-digital conversion (20), are compared in an evaluating unit (22) individually with criteria stored in a memory (23) for each type of coin to be accepted.