74 Keysight InfiniiVision 2000 X-Series Oscilloscopes User's Guide4 Math WaveformsA scale unit of U (undefined) will be displayed for math functions when two sourcechannels are used and they are set to dissimilar units and the combination of unitscannot be resolved.Math OperatorsMath operators perform arithmetic operations (add, subtract, or multiply) onanalog input channels.• “Add or Subtract" on page 74• “Multiply or Divide" on page 75Add or SubtractWhen you select add or subtract, the Source 1 and Source 2 values are added orsubtracted point by point, and the result is displayed.You can use subtract to make a differential measurement or to compare twowaveforms.If your waveforms' DC offsets are larger than the dynamic range of theoscilloscope's input channels you will need to use a differential probe instead.* When the FFT source is channel 1, 2, 3 or 4, FFT units will be displayed in dBV when channel unitsis set to Volts and channel impedance is set to 1 MΩ. FFT units will be displayed in dBm whenchannel units is set to Volts and channel impedance is set to 50Ω. FFT units will be displayed as dBfor all other FFT sources or when a source channel's units has been set to Amps.Math function Units
