Reference Section
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111
Chapter 5
Output Zero
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Subtracts the steady-state current offset (in VC mode) or voltage offset (in IC
mode).
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Activated by pressing the
button in the Output Zero box, or by checking
the checkbox and manually adjusting the value to the left of the button.
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See also Leak Subtraction, Bridge Balance.
The purpose of this control is to zero the output, that is, to remove the DC voltage.
Output Zero works by sampling the current or voltage over a ~70 ms time window
immediately after pressing the button, and then subtracting this value from all
subsequent Scaled Output signals. Unlike Leak Subtraction or Bridge Balance, it does
not account for currents or voltages that change as a result of time-varying command
pulses; it simply provides a constant offset adjustment.
The Auto Output Zero only affects the signal on the Scaled Output. In other words,
the cell is not affected by the Output Zero command. No other input or outputs are
affected.
Output Zero is useful for recording small signals that are riding on a large, constant
offset current or voltage. However, in general we recommend that it not be used, since
potentially useful information about the biological signal is lost.
