Making Measurements 5
6000 Series Oscilloscope User’s Guide 217
When you select 1–2, channel 2 voltage values are subtracted
from channel 1 voltage values point by point, and the result is
displayed.
You can use 1– 2 to make a differential measurement or to
compare two waveforms. You may need to use a true differential
probe if your waveforms have DC offsets larger than the
dynamic range of the oscilloscope's input channel.
To perform the addition of channel 1 and channel 2, select Invert
in the Channel 2 menu and perform the 1 – 2 math function.
1Press the Math key, press the 1–2 softkey, then press the
Scale or Offset sofkeys if you want to change the scaling or
offset for the subtract function.
•Scale — lets you set your own vertical scale factors for
subtract, expressed as V/div (Volts/division) or A/div
(Amps/division). Units are set in the channel Probe menu.
Press the Scale softkey, then turn the Entry knob to rescale
1–2.
•Offset — lets you set your own offset for the 1– 2 math
function. The offset value is in Volts or Amps and is
represented by the center horizontal grid line of the
display. Press the Offset softkey, then turn the Entry knob
to change the offset for 1– 2.
A scale unit of U (undefined) will be displayed for scale and
offset if channel 1 and channel 2 are set to dissimilar units in
the channel Probe Units softkey.