A device for coupling load cells or extensometric gauges for application in mechanical testing of materials. It enables the combination of magnitudes such as force, mass, displacement, pressure, temperature, torque, acceleration, extension, mechanical or electrical stress, current, frequency and resistance. It consists of 40 multiplexed channels that offer several port configurations with extensometric gauges and screen display. It has an RS232 or IEEE 488 PC connection, is compatible with Labview and enables printing.