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5.2 Partial discharge detection
The UltraView detects partial discharges based on the sound they emit. The different filters
available on the UltraView filter out background noise and concentrate on the high and ultrasonic
frequencies where the sound of partial discharges typically is much stronger than the background
noise.
The UltraView will automatically determine when a detected sound source is likely to be a partial
discharge. This autodetection works for AC frequencies of 50 and 60 Hz.
When the camera has detected a possible partial discharge, the camera will show a PRPD (phase-
resolved partial discharge) pattern for it on the top of the screen. By default, the pattern is shown
in a small window. Press the window to enlarge it. Press once more to make it small again. The
Cloud and UltraView Viewer Pro use the PRPD pattern to classify the partial discharge and assess
its severity. For this to be accurate, the user needs to set the distance to the partial discharge
(
section 5.2.2 Distance
).
5.2.1 FILTERS
The available filters depend on the
camera’s application mode, you can choose to activate the
relevant optimal filters for finding leaks of partial discharges.
Norm (10 to 30 kHz):
The best alternative for all cases with little background noise. Offers the
best detection distance.
High (20 to 30 kHz):
Offers good detection distance while filtering out most background noise
sources.
Ultr (30 to 65 kHz):
Effectively filters out background noise at the expense of reduced detection
distance. Typically only to be used at short distances.
Full (2 to 65 kHz):
This filter is only available when enabling all available filters from the
advanced settings. It utilises the full frequency range of 2 to 65 kHz and has a flat frequency
response. This filter is not ideal for finding partial discharges, since it will be affected by low-
frequency background noise and might not be able to pick up very silent sound sources.
5.2.2 DISTANCE
The camera screen includes buttons for setting the distance to the detected partial
discharge. Use the + and - buttons to select the distance that you estimate to be the
most accurate. The distance setting allows the UltraView to properly compensate for the
reduction or increase in sound intensity due to the location of the sound source. The
UltraView uses this information to estimate the severity of the partial discharge.