Decibel Calculations - Fluke 8508A User Manual

8508A
Users Manual
Recall Division Constant
Z?
(Nr3) Recalls the defined value of z.

Decibel Calculations

Decibel operations calculate, and express in decibels, the ratio of the reading to one of
four standard references: unity, and 1 mW in either 50 , 75
calculation is set as the final part of any calculation, it is also possible to use the other
Math operations to alter the effective reference value.
Enable dB Calculation
Selects the decibel operation to be performed on the measurement. This operation
computes the dB ratio of a corrected A-D result and a stored reference value "R".
ON / OFF
Displays the result of the calculation 20log[(Reading)/dB Ref].
Power On and Reset Conditions
OFF.
Set dB Reference Value
The user defines the value of the reference R, to be used in dB calculation. All selections
are mutually exclusive.
UNITY
Selects a dB reference of unity, in whole units of the active function.
Each of the following commands selects the dB reference voltage (as shown in
parenthesis), which corresponds to 1 mW in the given impedance. These are only
available for use in voltage functions
Power On and Reset Conditions
UNITY.
4-30
Recall Division Constant
DB
Enable dB Calculation
DB_REF
Set dB Reference
R50 50
R75 75
R600 600
Z?
phs ON
OFF
UNITY
phs
R50
R75
R600
(i.e., 0.223606800V)
(i.e., 0.273861280V)
(i.e., 0.774596670V)
adj237f.eps
or 600 . As the dB
adj238f.eps
adj239f.eps