Macro: ZeroMode=Avg

Zero Average (shortened to Zero Av on the toggle buttons) determines the DC value of the waveform by averaging all 1024 trace samples together. It then subtracts this value from each sample of the waveform. This is an ongoing process, repeated on every display update as long as Zero Av is set.

The purpose of Zero Average (and the following Zero Peak) is to remove the constant (DC) value from a waveform to allow you to view only the varying (AC) portion. Unlike Zero Cursor, these do affect the cursor readouts and .TXT file output, though they don't change the data for other file formats. (You can always apply any Zero function later when you open the file.)

This option shouldn't be needed for most sound card inputs, since they are AC-coupled by design. However, some cards are better at this than others. Due to a leaky coupling capacitor or similar problem, a small offset voltage may be present. This can be a particular problem on Mic inputs, which have a high gain stage between the input and the ADC. The trace may be many millivolts above or below the screen zero, which means when you try to magnify it (PgUp) it can be driven off the screen.

Macro Notes:

ZeroMode=Avg sets Zero Average mode. Note that attempts to use this command in Spectrum or Histogram modes will result in "Control disabled. Aborting macro."

See also Zero (Cursor, Average, or Peak)

• Back to Zero Cursor (Zero Cr) Mode
• Ahead to Zero Peak (Zero Pk) Mode
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