To provide a meter selector allowing connection of a plurality of measuring instruments to allow use of them even if the measuring instruments themselves have no scaling function when changing over and using measurement signals from the plurality of measuring instruments each having a different measurement range.

This measuring device has: the plurality of measuring instruments each having the different measurement range measurable within prescribed accuracy, and each outputting a measurement value as a pulse; the meter selector allowing input of the respective measurement outputs from the plurality of measuring instruments, and selecting one of the measurement outputs on the basis of the value of the measurement output to output it; and at least one scaler inserted in input of the meter selector. The scaler is adjusted such that the plurality of measurement outputs each have the same pulse weight regardless of the selection of the meter selector.