HP 8712C User Manual page 277

Calibrating for Increased Measurement
Accuracy
Check the Calibration
Transmission Transmission tracking is a transmission measurement error
Tracking term. It is a measure of the corrected THRU standard.
A typical transmission tracking error is fO.1 dB. Most likely
this term wilI be dominated by trace noise.
6-34
Figure 6-6. Typical Transmission Tracking Error Term Figure 6-6. Typical Transmission Tracking Error Term