Usage Method of Low-power Objective for Metallographic Microscopes
① Illumination Alignment of the Metallographic Microscope Turn the coarse focus knob with the left hand to raise the tube or lower the stage. Then rotate the revolving nosepiece to align the low-power objective with the aperture of the stage. (When rotating, ensure the notch on the upper part of the objective engages with the fixed buckle on the base.) Open the iris diaphragm. Rotate the condenser lifting knob to adjust the top lens plane of the condenser to be slightly lower than the plane of the stage. Keep both eyes open, and adjust the angle of the mirror until the light in the field of view is uniform with moderate brightness.
② Placing the Specimen Slide on the Metallographic Microscope Put a specimen slide on the stage with the coverslip side facing upward. Secure it on the slide holder, then turn the holder knob to center the target specimen area over the aperture.
③ Focus Adjustment of the Metallographic Microscope Turn the coarse focus knob to bring the low-power objective to less than 6 mm away from the specimen slide. (During adjustment, watch the gap between the objective and slide from the side. Never turn the coarse knob while looking through the eyepiece, to prevent the lens from hitting and damaging the slide.) Keep both eyes open. Slowly rotate the coarse focus knob to lift the lens or lower the stage. When the image appears in the field of view, turn the fine focus knob until a sharp clear image is obtained. If the image is off-center, move the specimen slide up, down, left or right. (Note: The moving direction of the slide is opposite to the moving direction of the image seen in the eyepiece.) If the working distance is exceeded and no image can be found during focusing, repeat the above steps from the beginning.
