Conventional ultrasound imaging systems typically include a hand-held probe coupled to a processing and display unit. A first seat, such as a seat of a motorcycle, is connected to the frame. To maintain reliable and repeatable solenoid spill valve behavior for small fractional trapping volumes, methods are proposed that involve energizing the solenoid spill valve for a minimum angular duration below a trapping volume fraction threshold. The control section utilizes standby time T1, instead of the standby time T, if a last job executed by the job executing section is according to job data input through the interface section.