A wireless device (150) and related method of monitoring or controlling a process includes a housing (200) having a mounting structure (300) for rigidly connecting the wireless device with respect to a solid surface, such as within a processing facility (125). An antenna assembly (250) has a movable connection (e.g., using set screw 310 and channel 425) with the housing (200), wherein the antenna assembly can be moved with respect to the housing (200), and wherein the movable connection maintains a hermetic seal and an explosion-proof flame path of the housing and the antenna assembly. The wireless device (150) can include a transmitter, receiver or a transceiver coupled to the antenna assembly (250), wherein the wireless device (150) is operable to wirelessly transmit using the antenna assembly to a remote receiver or receive information from a remotely located transmitter.