Agilent Technologies E4418B Service Manual page 75

Note The power meter may be returned to the nearest Agilent Technologies
office to have the power reference oscillator checked and/or adjusted.
For this adjustment the following mathematical assumptions are made:
Equation 1:
can be manipulated to give the following:
Equation 2:
V
by using the following assumptions:
V
The error in doing this is:
–
So if
be ignored. In practice
than 0.01%.
Agilent E4418B/E4419B Service Guide
Power Meter
Power
ref
Thermistor
Mount
Figure 3-3: Adjustment Setup
(
2V V
comp
P = ---------------------------------------------------------------------------------- -
meas (
4R CalibrationFactor
= V + V
–
1 comp 0
2 2
(
V = V V
– – –
0 1 1
2 2
(
V + V 2V V
–
1 0 1 0
( ) 2V
2V V V «
–
0 1 0 comp
Power Reference Oscillator Level Adjustment
Agilent 432A
Power Meter
V
RF
V
comp
2 2
)
V + V V
– –
1 0 0 1
)
3
–
2
( ) (
V 10 4R
–
comp
2
)
0
2 2
) ( )
V V = 2V
– – –
0 1
( )
, that is,
V V
–
1 0
and
V ~ 4Volts V
c omp
Adjustments
Digital
Voltmeter
) CalibrationFactor (
2
+ 2V V = 2V
0 1 0 0
then the error can
V « V
0 comp
. The error is less
< 400µV
0
+
INPUT
INPUT
)
( )
V V
–
1 0
3-7