A foaming composition is provided comprising a particulate ingredient having a plurality of internal voids containing entrapped supercritical fluid having a critical temperature of at least about 10\xb0 C. While moving the portions to be imaged of the subject continuously or stepwise in the imaging space and disposing the subject, a whole-body image of a large region of the subject is created. Disposed in the measuring space is a support unit for support of the welding componentry. At least one of the electrodes is spaced apart from the workpiece. In addition, at least one or two of the lower electrode film, the middle electrode film and the upper electrode film is thicker than the rest thereof.