Determining Cable Stability Terms (Ctm1 Ctm2 Ctp1 Ctp2 ) - HP 8719ET Reference Manual

Determining System Measurement Uncertainties
Determining Cable Stability Terms (C , C , C , C , C , C )
R1 R2 TM1 TM2 TP1 TP2
Figure 10-2 Cable Stability with a Short Connected
Figure 10-2 and Figure 10-3 demonstrate the concepts useful in determining cable
transmission stability. A short is connected to the free end. The DATA/MEM feature
provides an indication of the two-way cable transmission stability. The one-way
transmission magnitude stability is determined by dividing the two-way magnitude
measurement by two before it is converted to linear. A 0.013-dB peak on the chart yields
(0.013/40) −1 or 0.00075. The one-way
transmission magnitude stability estimated as 10
transmission phase stability is determined by dividing the two-way phase measurement
by two.
Figure 10-3 Cable Stability with a Short Connected
Cable movement often has a much larger effect on phase measurements than magnitude
measurements.
10-7