The invention is a security alarm system component for securing movable objects. At least two heat-shrinkable sheets are attached, by one of their edges, in the region of the join between the base of the box and the sides of the lateral band of this box. A platen of attenuating material extends outward from adjacent to, and surrounding, the irradiated surface of the test material. It is possible to keep the distance larger in a thickness direction between the absorbent sheet member and the back sheet in the vicinity of the opening and fit a portion around the opening of the absorbent sheet member to a wearer. The barrier layer is smaller in size than the backsheet. Thereafter, the difference in the ac magnetic susceptibility of the reagent before and after the association with the biomolecules is measured and the concentration of biomolecules in the sample solution is determined.