Before taking a measurements of a composite waveform  on a single channel of the oscilloscope, the user must

1. Ensure the VAR controls are in their CAL'D positions.

2. Ensure the VAR controls are turned anticlockwise.

3. Set the TRIGGER SOURCE switch to the channel where the signal is being inputted.
4. Set the TRIGGER COUPLING switch to the channel where the signal is being inputted.

5. Set the TRIGGER COUPLING switch to AUTO.

6. Set the INPUT COUPLING switches to AC and centre the dot on the screen using the HORIZONTAL and VERTICAL POSITION controls.

7. Set the INPUT COUPLING switches to GND and centre the line on the screen using the HORIZONTAL and VERTICAL POSITION controls.
8. Set the INPUT COUPLING switches to DC to show only the dc part of the waveform. 

9. Set the INPUT COUPLING switches to DC to show the entire waveform.

10. Set the TIME/DIV settings to a scale suitable for measurement.

11. Set the TRIGGER SOURCE and VERT MODE switches to X-Y.

12. Set the VOLT/DIV settings to a scale suitable for measurement.

13. Adjust the TRIGGER LEVEL control to chose the voltage point at which the wave begins to draw.
14. Adjust the HORIZONTAL POSITION control to chose the voltage point at which the wave begins to draw.

Note: Composite waveform = ac waveform + dc waveform (i.e. ac "riding" on a dc)