A: 1. Open the battery cover before use, install 3 7-cell batteries, and the positive pole is in the direction of “light source switch”;
2. Insert the fiber (jumper) to be tested into the fiber interface, and insert the other end into the backlight window for better effect.
3. Look at the eyepiece and press the on/off indicator to switch (illuminance);
4. Adjust the focal length wheel to find the clearest observation point;