According to one embodiment of the invention, there is provided an N-port automatic calibration device comprising N-ports, wherein each port is adapted to be coupled to a port of an N-port multiport test set. A gas block is coupled to the barrel, the gas block having a bore therethough. The appliqu\xe9 is attached to a surface of a tool blank and then metallurgically bonded and coated by the BRAZOL\xae or Co\u2014P process. Another RF input-output port corresponding to the resonant frequency of 19F nucleus is connected with an end of the coil via another tuning and matching device.