Where to Look for More Information

Additional information about many of the topics discussed in this chapter is located in the following areas:

wChapter 2, YMaking Measurements,” contains step-by-step procedures for making measurements or using particular functions.

nChapter 4, “Printing, Plotting, and Saving Measurement Results,” contains instructions for saving to disk or to the analyzer internal memory, and printing and plotting displayed measurements.

nChapter 6, “Application and Operation Concepts,” contains explanatory-style information about many applications and analyzer operation.

Increasing Measurement Accuracy

Connector Repeatability

Connector repeatability is a source of random measurement error. Measurement error-corrections do not compensate for these errors. For all connectors, you should frequently do the following:

ninspect the connectors.

nclean the connectors.

ngauge the connectors.

nuse correct connection techniques ( See Chapter 2, ‘Ihble 2-l.)

Interconnecting Cables

Cables connecting the device under test to the analyzer can contribute random errors to your measurement. You should frequently do the following:

ninspect for lossy cables.

w inspect for damaged cable connectors.

npractice good connector care techniques,

nminin&e cable position changes between error-correction and measurements

w inspect for cables which dramatically change magnitude or phase response when flexing. (This may indicate an intermittent problem.)

Temperature Drift

Electrical characteristics will change with temperature due to the thermal expansion characteristics of devices within the analyzer, calibration devices, test devices, cables, and adapters. Therefore, the operating temperature is a critical factor in their performance. During a measurement calibration, the temperature of the calibration devices must be stable and within 25 f5 OC.

w use a temperature-controlled environment.

nensure the temperature stability of the calibration devices.

navoid handling the calibration devices unnecessarily during calibration.

w ensure the ambient temperature is f 1 OC of measurement error-correction temperature.

6-2 Optimizing Measurement Results