Basic Measurements; Ac Voltage Offset - Keithley 2000 User Manual

AC voltage offset

The Model 2000, at 5
volts with the input shorted. This offset is caused by the offset of the TRMS converter. This
offset will not affect reading accuracy and should not be zeroed out using the REL feature. The
following equation expresses how this offset (V
Displayed reading
Example: Range = 1VAC
Offset = 100 counts (1.0mV)
Input = 100mV RMS
Displayed reading
Displayed reading
Displayed reading
The offset is seen as the last digit, which is not displayed. Therefore, the offset is negligible.
If the REL feature were used to zero the display, the 100 counts of offset would be subtracted
from V , resulting in an error of 100 counts in the displayed reading.
IN
See Section 3 — Measurement Options for information that explain the configuration options
for DC and AC voltage measurements.
digits resolution, will typically display 100 counts of offset on AC
OFFSET
2
= V + V
IN OFFSET
2
= 100mV + 1.0mV
= 0.01V + 1 10
= 0.100005

Basic Measurements

) is added to the signal input (V
2
2
6 –
V
2-21
):
IN