Induced Noise - DTX CableAnalyzer

Users of the DSP-4x00 Series CableAnalyzers may be familiar with its unique ability to detect noise during an Autotest. If this happens, a warning is given on the instruments screen. Users immediately perceive there is a problem, which often is not the case. All that has happened, is the instrument detected enough induced noise to affect the measurement accuracy. Upon this detection, the instrument repeats the measurement until a stable reading is obtained. This is done automatically with no intervention from the user ensuring Level III Accuracy under any conditions.

The DTX CableAnalyzer filters out externally induced noise using a different method (different hardware inside). The instrument uses a precise narrow band filter, which reduces the chances of measuring any unwanted stray externally induced voltages. In addition to this, thanks to the new hardware design, the stimulus voltage is greater than the DSP Series. This adds another layer of protection against small externally induced signals affecting accuracy and the need to repeat the measurement. It could still happen of course, but the DTX CableAnalyzer always measures the inactive pairs during an Autotest to see if noise is being induced.
If you think there is noise on your cabling system, use the Impulse Monitor feature within the instrument. Details on this can be found here