The specification discloses a system for mounting a communications antenna and a solar panel on an explosion-proof housing that does not require the use of conduit ports of the explosion-proof housing. The reels are rotated and stopped to randomly place symbols on the reels in visual association with a display area. The main dense pattern comprises a first outmost sub-pattern and a second outmost sub-pattern, wherein the first outmost sub-pattern and the second pattern are not adjacent to each other. The graphical identification may occur based on a selection of a part in one of the entities. 03 to 10 milli-Torr for up to a few thousand seconds at temperatures below about 35\xb0 C. At least one outer surface portion of the inner support is coupled with at least one interior surface portion of the effector device such that forces applied to the effector device are at least partially transferred to the inner support for measurement by the sensor.