Measurement Noise - Agilent Technologies E4418B Service Manual

Measurement Noise

Power sensor dependent (refer to Table 1-2 and Table 1-3).
Averaging effects on measurement noise. Averaging over 1 to 1024
readings is available for reducing noise. Table 1-3 provides the
measurement noise for a particular power sensor with the number of
averages set to 16 for normal mode and 32 for x2 mode. Use the "Noise
Multiplier" for the appropriate mode (normal or x2) and number of
averages to determine the total measurement noise value.
For example, for an Agilent 8481D power sensor in normal mode with the
number of averages set to 4, the measurement noise is equal to:
Number of
Averages
Noise Multiplier
(Normal Mode)
Noise Multiplier
(x2 mode)
Agilent E4418B/E4419B Service Guide
(<45 pW x 2.75) = <124 pW
Table 1-2: Noise Multiplier
1 2 4 8
5.5 3.89 2.75 1.94
6.5 4.6 3.25 2.3
Power Meter Supplemental Characteristics
16 32 64 128
1.0 0.85 0.61 0.49
1.63 1.0 0.72 0.57
Specifications
256 512 1024
0.34 0.24 0.17
0.41 0.29 0.2
1-7