A multiphase power converter includes one or both of a phase control circuit and a valley switching locking circuit. The image pickup element 11 has a light receiving area 102 formed on a substrate 101, an insulation layer 104 deposited on a light receiving area 102, and a microlens 106 formed on the insulation layer 104 and collecting incident light onto the light receiving area 102. The system is automated and may be employed in an unattended operation for identification and quantification of elemental or specie contaminants. The valve box further includes a lid that is positioned over the housing chamber opening. A plurality of shims can be removeably installed and uninstalled between the abutment faces of the base and the walls of the adjusting plate to adjust the position of the gage relative the vehicle body.