An optical compensation film and an elliptical polarizing plate, for realizing a liquid crystal display improved in gray-scale inversion, having a wider viewing angle property and being excellent in industrial production is provided. Certain such methods and systems provide the additional function of compensating for a sample volume determined to be less than adequate in order to proceed with an accurate analyte concentration measurement. There is a means for controlling the fluid flow that can prevent the circulation of a fluid in this passage, and a handling means utilizing a pivoting lever that can be manually actuated by an operator. It is possible in this manner to monitor not only those wafers which were just previously taken out or put in by the transport robot, but also all other wafers present in the magazine. A crank handle is connected with said crank mechanism for rotating the drive gear; which causes the crank mechanism to move the movable elements in opposed directions at equal rates.