Agilent Technologies 3458A Calibration Manual page 28

Caution
28 Chapter 3 Adjustment Procedures
the frequency and period measurement functions: adjusts the attenuator and
amplifier high frequency response; and adjusts the Time Interpolator timing
accuracy. Following this adjustment, the internal circuits have constant gain
versus frequency.
Equipment required:
•
Agilent 3325A Synthesizer/Function Generator or equivalent.
•
3V Thermal Converter, Ballantine 1395A-3 or equivalent.
•
1V Thermal Converter, Ballantine 1395A-1 or equivalent.
•
0.5V Thermal Converter, Ballantine 1395A-0.4 or equivalent.
•
50W BNC cable (keep this cable as short as possible)
•
50W resistive load (typically a 50W carbon composition or metal film
resistor).
•
BNC to Banana Plug Adapter--Agilent 1251-2277 or equivalent.
In the following procedure, the output voltage of the
synthesizer is adjusted with the thermal converters in-circuit.
Thermal converters are typically easily damaged by voltage
overload. Use extreme care to ensure the voltage applied to the
thermal converters does not exceed the thermal converter's
maximum voltage rating.
Procedure
In the following procedure, steps 1 through 12 characterize the frequency
flatness of the synthesizer and cabling configuration. The equipment setting
determined from this characterization are then used in the remaining steps to
precisely adjust the multimeter.
Note
The voltages referenced in this procedure are 3V, 1V and 100mV rms for
the SCAL 10, SCAL 1, and SCAL .1 commands, respectively. If
necessary, you can use any value between 3V and 10V rms wherever 3V is
referenced, 300mV to 1V rms wherever 1V is referenced, and 30mV to
100mV wherever 100mV is referenced (make sure not to exceed the
voltage rating of the thermal converters). (You still execute the SCAL 10,
SCAL 1, and SCAL.1 commands regardless of the rms voltage value used).
Whenever making low-level measurements, take precautions to minimize
noise and interference in the test setup. Refer to "Test Considerations" in
Chapter 4 for more information.
1. Execute the ACAL AC command. Following the autocal, execute the
RESET command.
2. Set the front panel Terminals switch to Front. Set the Guard switch
to the To LO position.