10-6
Determining System Measurement Uncertainties
Determining Cable Stability Terms (C
R1
, C
R2
, C
TM1
, C
TM2
, C
TP1
, C
TP2
)
Determining Cable Stability Terms
(C
R1
, C
R2
, C
TM1
, C
TM2
, C
TP1
, C
TP2
)
Cable stability is dependent on the cable used and the amount of cable movement between
calibration and measurement. Values for cable reflection stability are determined by
connecting a fixed load to the free end of the cable and measuring the change in reflection
coefficient after flexing the cable through the normal range of cable movement for a
particular setup. Cable transmission stability is determined by connecting a short to the
free end of the cable and measuring the change in reflection coefficient due to changes in
cable position.
Figure 10-1, Figure 10-2, and Figure 10-3 show an example that demonstrates the
concepts useful in determining cable stability. In each case, a cable (HP part number
8120-4779) was connected to port 1, with a fixed load connected to the free end. A reference
trace is obtained by measuring S
11
with the free end held close to port 2 and storing the
results in memory. Two additional S
11
measurements are made; one with the cable flexed
out to its straight position and the other with the cable positioned back to the same
location as reference trace. The flexed position demonstrates the effect of moving the cable
after calibration, the repeatability trace in Figure 10-1 demonstrates the stability of the
cable when moved to its original position.
Figure 10-1 Cable Stability with Fixed Load Connected
Figure 10-1 demonstrates the concepts useful in determining cable reflection stability. A
fixed load is connected to the free end. The DATA-MEM feature provides an indication of
the cable reflection stability. A 60-dB peak on the chart yields a reflection stability
estimated as 10
(
−
60/20)
or 0.001.
Summary of Contents for 8719ES
Page 6: ...vi ...
Page 10: ...Contents x Contents ...
Page 11: ...1 1 1 HP 8719 20 22ES Specifications and Characteristics ...
Page 60: ...1 50 HP 8719 20 22ES Specifications and Characteristics Instrument Specifications ...
Page 61: ...2 1 2 HP 8719 20 22ET Specifications and Characteristics ...
Page 98: ...2 38 HP 8719 20 22ET Specifications and Characteristics Instrument Specifications ...
Page 99: ...3 1 3 Front Rear Panel ...
Page 111: ...4 1 4 Menu Maps ...
Page 113: ...4 3 Menu Maps Menu Maps Figure 4 2 Menu Map for Copy ...
Page 114: ...4 4 Menu Maps Menu Maps Figure 4 3 Menu Map for Display ...
Page 115: ...4 5 Menu Maps Menu Maps Figure 4 4 Menu Map for Format Figure 4 5 Menu Map for Local ...
Page 116: ...4 6 Menu Maps Menu Maps Figure 4 6 Menu Map for Marker Marker Fctn and Marker Search ...
Page 118: ...4 8 Menu Maps Menu Maps Figure 4 9 Menu Map for Power and Sweep Setup ET only ...
Page 119: ...4 9 Menu Maps Menu Maps Figure 4 10 Menu Map for Power and Sweep Setup ES only ...
Page 120: ...4 10 Menu Maps Menu Maps Figure 4 11 Menu Map for Preset ...
Page 121: ...4 11 Menu Maps Menu Maps Figure 4 12 Menu Map for Save Recall ...
Page 122: ...4 12 Menu Maps Menu Maps Figure 4 13 Menu Map for Scale Ref ...
Page 128: ...5 1 5 Hardkey Softkey Reference ...
Page 194: ...6 1 6 Error Messages ...
Page 222: ...7 1 7 Options and Accessories ...
Page 234: ...8 1 8 Preset State and Memory Allocation ...
Page 253: ...8 20 Preset State and Memory Allocation Memory Allocation ...
Page 254: ...9 1 9 Understanding the CITIfile Data Format ...
Page 269: ...9 16 Understanding the CITIfile Data Format Useful Calculations ...
Page 270: ...10 1 10 Determining System Measurement Uncertainties ...
Page 281: ...10 12 Determining System Measurement Uncertainties Measurement Uncertainty Equations ...