A scanning device for the double beam leitz interference microscope

Summary The Leitz double beam interference microscope and its microscope photometer attachment have been rebuilt to a scanning instrument. The wide separation between the reference and object beam enables measurements of optical path differences (opd) in relatively large microscopic objects or in closely packed smaller objects without difficulties caused by the lack of free space for the reference beam. This advantage can now be combined with that of a scanning device. Using the system developed integrated values of the opd and hence the dry mass content of heterogeneous microscopic objects can be determined.Scanning in interference contrast is carried out in the image plane with a 0.1 mm diaphragm driven by two direct current motors. The intensity of the light passing the diaphragm is kept constant by adjustment of the glass wedge in the reference beam by means of a servo system. The displacement of the wedge, being proportional to the opd between the microscopic object and the free background, is recorded and integrated. The final value given by the integrator is proportional to the dry mass of the microscopic object.