B&K Precision 5491B - Manual User Manual
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To set the reference impedance, perform the following steps:
1. Press
→
for dBm math operation and the present reference value is displayed:
REF：0000
2. Use
and
keys to choose a numerical place and use
and
keys to
increment or decrement the digits. Enter a value from 1
Ω to 9999 Ω.
3. Press
(ENTER) to confirm the reference impedance, the message
“SAVED” will be displayed
for a moment. The meter will then return back to the measurement status.
4. The display will show the result of the dBm calculation.
If you want to change the impedance reference value after the dBm function is enabled, you can do the
following:
1. Press
→
to enter the menu on the menu level.
“A: MATH MEU” will be displayed.
2. Press
to move down to the command level within the MATH MEU,
“5: dBm REF” will be
displayed.
3. Press
to enter the parameter level and the present impedance reference value will be
displayed: REF: 0000.
4. Use
and
keys to choose a numerical place and use
and
keys to
increment or decrement the digits. Enter a value from 1
Ω to 9999 Ω.
5. Press
(ENTER) to confirm the reference value, the message
“SAVED” will be displayed for a
moment, and the meter will return to the command level. Press
to cancel the reference value
input, and the meter will return back to the command level without changing the reference value.
6. Press
→
key to exit the menu and return to the dB math operation status.
NOTE:
The reference impedance and input impedance mentioned in this chapter are
completely different. The Input impedance is inherent to the instrument and cannot be
changed.
NOTE: dBm is valid for both positive and negative DC voltage.
NOTE:
The percent math operations are applied after the dBm or dB math calculation.