A compressed gas engine includes a plurality of reciprocating pistons within cylinders, the pistons being driven by compressed gas from a source tank. A surface of the actuator is set to a black and a surface of the substrate is set to a white. The molten molding resin 30 is injected into the molding part 43 to cover almost the whole of the terminal connecting portion. Each logical channel mapper converts a received data block mapped on a logical channel to a traffic in a predetermined format. Alternatively, the sensor housing can be fitted with a base member that has at least one flat face. Particles of the first and second types of gas are capable of reacting with the surface, when activated by the radiation beam.