Fluke CombiScope PM3370B User Manual page 60

HOW TO USE THE INSTRUMENT
VERTICAL
Use the POS control to adjust the ground level to any desired vertical
POS
position on the screen.
ST6158
9303
1
- Use the position control to position the line in the middle of the screen.
Observe that the channel identifier '1-' shifts with the trace.
- Press the AC DC GND key again to obtain ac input coupling.
Since the Probe Adjust signal is a pulse type signal with a 50% duty cycle, its
mean value is at the 50% amplitude level of the input signal. When the input is ac
coupled, the mean value will be displayed at the ground level of the oscilloscope.
As a result of this, the displayed waveform is centered on the screen.
1
POS
4 - 15
POSITION
MAT4171