Axle counter with variable threshold setting

An axle counter comprising at least one electromagnetic rail contact (SCH), which is attached to the rail of a track (GL) and comprises a transmitter (S, SK) generating an alternating electromagnetic field and at least one receiver (E, EK) detecting the alternating electromagnetic field, and an evaluating circuit (AS) which senses in the output of the receiver (E) a change in the alternating electromagnetic field caused by a wheel passing on the rail, compares said change with a predetermined threshold value, and, when it exceeds the threshold value, interprets it as an axle passage and feeds a count pulse to presence-of-trains indicating equipment, characterized in that an overwritable memory (SMA, SMI) is provided for storing the predetermined threshold value or values from which the predetermined threshold value can be calculated at any time, that enabling means are provided which permit the contents of the memory to be overwritten in response to a special setup command, and that further means (AD) are provided which determine a new predetermined threshold value, or values required to calculate a new predetermined threshold value, from a receiver output signal obtained under standard conditions or from changes in receiver output signals obtained over a prolonged period of time, and feed said value or values to the memory.