Calibration, Adjustment and Operation of Stereomicroscope
The pre-use adjustments for a stereomicroscope mainly include focusing, diopter adjustment, interpupillary distance adjustment and bulb replacement, which are described separately below.
Focusing: Insert the stage plate into the stage mounting hole on the base. Use a frosted glass stage plate for transparent specimens and a black-and-white stage plate for opaque specimens. Loosen the locking screw on the focusing slide, and adjust the height of the microscope body to achieve a working distance roughly matching the magnification of the selected objective lens. Tighten the locking screw after adjustment. A flat object such as printed paper, a ruler or a set square is recommended for focusing.
Diopter Adjustment: First, turn the diopter rings on both left and right eyepiece tubes to the zero mark. Normally, observe through the right eyepiece tube first. Turn the zoom knob to the low-magnification position, then rotate the focusing knob and the diopter ring to focus on the specimen until the image is sharp. Next, switch the zoom knob to the high-magnification position and adjust again until the image remains clear. Then observe through the left eyepiece tube. If the image is blurry, axially adjust the diopter ring on the left eyepiece tube to obtain a sharp image.
Interpupillary Distance Adjustment: Swing the two eyepiece tubes to change the exit pupil distance. The interpupillary distance is properly set when the two circular fields of view merge completely. Note that due to individual differences in vision and eye accommodation, separate focusing alignment should be performed for different users, or for the same user at different times, to achieve optimal observation results.
Bulb Replacement: Before replacing either the upper or lower light source bulb, make sure to turn off the power switch and unplug the power cord from the socket. For the upper light source bulb: Unscrew the knurled screws of the upper light housing, remove the housing, take out the faulty bulb from the socket, fit a new bulb, then reinstall the housing and knurled screws. For the lower light source bulb: Remove the frosted glass or black-and-white stage plate from the base, replace the faulty bulb with a new one, then refit the stage plate. Wipe the glass envelope of the new bulb with a clean soft cloth or cotton swab after replacement to ensure good illumination.
