9-8 Option 100 Fault Location and SRL
Characteristics
SRL Measurement Uncertainty vs Connector Fault
SRL Measurement Uncertainty vs
Connector Fault
As discussed earlier, three factors affect the measurement uncertainty:
• system directivity
• system and test lead stability
• cable connector mismatch
System directivity can be measured by connecting the 75 or 50 ohm load
standard to the test lead connector and observing the magnitude of the
highest response. The highest response is the system directivity.
See “2. Calibrate the Analyzer” on page 4-4.
Test lead stability can be measured by connecting the 75 or 50 ohm load
standard to the test lead connector, wiggling the cable and observing the
response. See “2. Calibrate the Analyzer” on page 4-4.
The cable connector mismatch can be measured by selecting the SRL
measurement and “Connector Fault.” The fault response at the connector
is displayed by the marker.
The connector mismatch can be improved by the proper connector model.
See “4. Determine the Connector Model” on page 4-8.
Minimizing Measurement Uncertainty
The best system performance can be attained by performing a good cal,
taking proper care of a high quality test lead cable, and using the best
connector model. When these three steps are taken, the optimized
connector response can be measured using the “Connector Fault” feature.
You can now calculate the measurement uncertainty using the following
procedure and worksheets. Note that the system directivity must also be
included when computing measurement uncertainty.
1. Convert the system directivity, fault location, and SRL log (dB)
responses to linear reflection coefficients using the following
equation:
Reflection Coefficient = 10
(SRL(dB)/20)
To Next Page
Loading...
Need help?
General
