The present invention provides a joint assembly for operatively coupling rotating parts. At an end on the discharge side of the fuel injector, an at least partially spherical body is formed which abuts at least partially against a wall of the receiving bore, a groove being circumferentially formed on the body in which the sealing ring is positioned. The beamformer compensates for propagation delays between the direct and reflected acoustic signals. In the TV-BGA package, a sealing post is adhered on the adhesive material coated on an edge of the PCB, and then a sealing cap is capped on the sealing post, so that a test vehicle is manufactured.