A first valve portion and a second valve portion are arranged in series in a flow passage within a valve casing to open and close the flow passage. The antenna device has a Y-shaped transmission plate spaced from a parallel grounded plate, and the feed ports are connected to the transmission plate at locations on the transmission plate which are on different branches of the Y-shape. The system may include two adders that supply the first and second output signals, respectively. This data may be processed to identify objects and the characteristics of the objects. Excluding the hardener, the mixing ratio of the polyglycidyl ether compound to the epoxy group-containing component of the mixture is 10 to 95 wt %.