Fluke 522A/6, Руководство оператора

Страница: 95 / 426

Front Panel Operation
How to Set Output
4
4-19
nn063f.eps
•
Range (Operating Range) selects autorange (auto) or lock (locked) for the present
range. When auto (the default setting) is selected, the calibrator automatically selects
the range that provides the best output resolution. When locked is selected, the
calibrator will not change ranges when you are editing the output. The locked
selection is usually made when you do not want range changes that may cause a
small perturbation in the output, e.g., when checking the linearity of a given
multimeter range.
How to Set AC Voltage Output
You may select an ac voltage output in volts or as a power output in dBm, where dBm is
10 log(Pout/.001) , where Pout is expressed in watts. The output range is 1 mV to
1000 V. When selecting dBm outputs, the Calibrator calculates dBm at a selected
impedance level. Based on this, the formula is:
20 log(V) - 10 log(Impedance * .001) = dBm.
Complete the following procedure to set an ac voltage output at the front panel
NORMAL terminals. If you make an entry error, press
G
to clear the display, then
reenter the value.

Caution
To prevent damage to the UUT, verify the applied voltage to the
UUT does not exceed the rating of the UUT insulation and the
interconnection wiring.
1. Press
R
to clear any output from the Calibrator.
2. Connect the UUT as described earlier in this chapter under “Connecting the
Calibrator to a UUT.”
3. Set the UUT to measure ac voltage on the desired range.
Output in volts Press the numeric keys and decimal point key to enter the desired voltage
output (maximum six numeric keys). For example, 2.44949.
Output in dBm Press the numeric keys and decimal point key to enter the desired power
output (maximum six numeric keys). For example, 10.0000. For a power output less than
1 mW (negative dBm values), press
I
to append the numeric entry with the negative
(
−
) symbol.
When you press the dBm key, the right most softkey becomes active. This allows the
dBm value and output impedance to be entered as a unit.
When output is entered in dBm, the Control Display appears as follows: