Patent ID: 7495754

Claim:
A method for adjusting a differential refractometer in which a measuring beam having passed a slit is passed through a flow cell having two cells divided by a partition wall inclined with respect to an optical axis of the measuring beam so that a sample solution is passed through one of the cells and a reference solution is passed through the other of the cells, the measuring beam passed through is reflected by a mirror and passed through the flow cell again, and the measuring beam is focused as a slit image so as to extend over separate portions of a photodetector, thereby detecting a displacement of the slit image, the method comprising the steps of: (a) equally focusing the slit image on the separate portions of the photodetector; (b) decreasing the quantity of light of measuring beam; (c) making parallel movement of the slit image on the photodetector by a predetermined displacement; and (d) increasing the quantity of light of the measuring beam.