Calibration system and interfacing method with a port calibration unit for each port

An interfacing method for a measurement application device, the interfacing method comprising:

• coupling a dedicated port calibration unit to each one of at least two ports of the measurement application device;
• and
• controllably coupling two port calibration units to each other via a central switching unit that comprises an input port for each one of the port calibration units,
• wherein each one of the port calibration units comprises a device coupling port that couples the respective port calibration unit to the respective port of the measurement application device, and a central coupling port that couples the respective port calibration unit to the respective input port of the central switching unit, and
• wherein each one of the port calibration units comprises a calibration section that comprises at least three calibration standards, and a switching section that controllably couples the device coupling port of the respective port calibration unit or the central coupling port of the respective port calibration unit to one of the at least three calibration standards, or that couples the device coupling port of the respective port calibration unit to the central coupling port of the respective port calibration unit.