Pseudo SRAM capable of arbitrating refresh requests with external access requests is provided. The problem presents itself of making available a sensor and a method for determining soot concentrations in flowing gases, with which even small amounts of soot can be reliably recorded. An intrinsic polarization of the ferroelectric film can be utilized as it is. Thus, the warp deformation of the substrate is corrected by a simple and cheap mechanism, and the clamp state can be reliably held. 0; Requirement : a specific solution has a viscosity of 25 to 100 Pa\xb7s at 25\xb0 C. The outer layer and the inner bladder portion contain apertures which are aligned to form a channel connecting the hollow chamber to the outside environment.