An apparatus comprising a memory and a controller. The filter element consists of at least one inner structure formed by openings, wherein the defining surface of the openings formed by the depth filter material constitutes a through-flow surface which is substantially perpendicular to the filter element plane. The bandpass filters each have a transmission line with the metallic plates disposed along its length. The determining unit determines a first period or a second period as transmission timing based on an estimated result. The thick and thin degree is shown with the number of the graphite pieces. , forwarder pages, are not included in the history list.