Tektronix A621, Instructions Manual

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NOTE.
Be sure the current loop has exactly 100 turns. A significant
error will result for each extra or missing turn.
AC accuracy check
1. Connect the 100 turn current loop, the multimeter current inputs,
and the signal generator output in series using the patch cords and
adapters. Set the multimeter to display AC
RMS
current. Refer to the
following figure.
Figure 6: Setup for maximum input current and accuracy checks
2. Adjust the signal generator output to between 49 mA
RMS
and
51 mA
RMS
as measured on the multimeter.
3. Connect the A621 to the oscilloscope, and make the following
oscilloscope settings:
■ Time base to 5 mS / div.
■ Vertical deflection to 500 mV / div.
■ Coupling to DC
4. Set the A621 sensitivity switch to 100 mV / A and center the trace
on the oscilloscope screen.
5. Clamp the A621 around the 100 turn current loop.
6. If necessary, readjust the signal generator output to read between
49 mA
RMS
and 51 mA
RMS
on the multimeter.
Maintenance
A621 Instructions 11