MEASURING SIGNAL RECORDING/REPRODUCING APPARATUS

PROBLEM TO BE SOLVED: To enable a recording/reproducing apparatus to execute calibration in a short time, by providing one external calibration signal input terminal common to a discrete data input terminal at each of channels to switch and select data and an external calibration signal by a switch provided preceding individual recording system circuits. SOLUTION: Data to be recorded are inputted input terminals 1CH-nCH and a calibration signal is inputted from outside to a calibration signal input terminal KIN. Switches SW11-SE1n change measurement inputs from the input terminals 1CH-nCH over to the calibration signal from the input terminal KIN. A switch SW2 switches a contact connected to the ground, contacts connected to points +100% and -100% and signal sources of AC signals and contact to which a calibration signal from the outside is connected. The calibration signal is inputted into the input terminal KIN to be recorded into corresponding channels through the switch SW2 and the switches 11-1n. This enables recording of external calibration signals into a plurality of channels with a simple structure.