Noise Detection - EA Technology UltraTEV Plus2 Operating Manual

EA Technology UltraTEV Plus Operating Manual 2388L015
2

5.6.6 Noise Detection

The UltraTEV Plus² incorporates a noise detection feature for TEV events. This feature continuously
monitors the background noise level during a TEV reading and alerts the user if the level is
approaching a point whereby the integrity of the reading may be adversely effected.
Noise is classed as any activity within the 3-80MHz band that is continuous in nature. These signals
are different to the short term events produced by TEV activity and can often mask the presence of
PD.
The UltraTEV Plus² report the noise level in dB below the main amplitude figure on each TEV
measurement screen. If this value reaches 10dB or above the unit displays a warning and prevents
the user continuing on the basic interpretation screen. This prevents the possibility of an incorrect
interpretation due to PD hidden within the background noise.
The remaining advanced screens, waveform, phase plot etc. will continue to function in the presence
of high background noise although it should be noted that the noise level may effect reported
amplitudes and count rates.
If the UTP² reports high background levels then attempts should be made to remove the source of
interference allowing the measurement to continue. Particularly frequent sources of interference
within indoor substations are electrical ballast florescent lighting, switch mode power supplies,
battery chargers and radio communication devices.
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