a sensor assembly that allows a sensor to be detachably mounted onto a fluoroscopic mount , such as a c - arm , is provided . the sensor assembly includes an electromagnetic sensor that is configured for outputting positional data relating to the fluoroscopic mount . the sensor includes a mount engaging element , and the sensor mount includes a sensor engaging element , both of which are configured to be removably mounted in an interference relationship with each other . the mount engaging element of the sensor can be a sensor housing , or alternatively , an element that is separate from the sensor housing . the sensor mount , which is composed of a non - ferromagnetic material , further includes a spacer for maintaining the sensor a prescribed distance from the ferromagnetic fluoroscopic mount , thereby minimizing any adverse ferromagnetic effects on the sensor .