1. pry open the mechanical metronome base under the newly bought Yin Peng spectrometer with a screwdriver.

2. Take out the filler and apply engine oil to the gear.

3. Cover the bottom cover again, stand on a horizontal surface, and remove the transparent panel.

4. Slide the metal block above to adjust the pendulum.

5. Pull the pendulum to tilt left or right.

6. Put down the metal block after use and cover it with a transparent cover for storage.