An interface detecting circuit and interface detecting method are provided, whereby operations can be carried out depending on peripheral devices connected to USB terminals, and whereby the system can be simplified and software load can be reduced. The flow meter electronics comprise a processing system and a single output port. An inner clearance is provided between the intermediate ring and the inner member such as to surround the circumference of the inner member. The compositions have improved throw power versus typical sulfonium salt electrodepositable compositions.