A mechanical numeral wheel counter comprising several numeral wheels and switch sensors set alternatively around the numeral wheels. The circumferences of the numeral wheels are divided into equal spaces and a sensing material is placed on each of the spaces. As the numeral wheels rotate, the status of each sensor will be different when the numeral wheel is at different position. Signals output from the sensors are processed by a computer capable of reading and recognizing the signals. A standard digital wave form can be obtained from the processed signals received by the computer from the sensors.