A network device receives configuration information for monitoring, via a network, control data for a monitored customer device. The head and cap form an ergonomically shaped bulbous handle. If the result of the calculation shows that the image is in the low luminance, the exposure and read out of the field data such as a difference in a luminance in each of the fields are carried out, and first and second field data are compared. The interior stent component has a generally tubular cylindrical body and is centered within the exterior stent component. The use of this charger makes it possible to charge the secondary battery such that it has a high capacity, or a higher capacity if necessary, without accelerating the deterioration of cycle life. The melter furnace is used to supply molten metal to an externally located holder furnace, which then recirculates molten metal back to the melter furnace.