Performing measurements
36
4.5
TEV comparative measurement between an internal and
external sensor
Because the PD pulses proliferate well on metallic surfaces, often only marginal
differences in the level can be measured at close range, which makes localising the
weak point exactly much more difficult. It is for exactly cases like these in which the
equipment affected by partial discharge cannot be identified precisely that a
comparative measurement between an internal and external TEV sensor is
recommended (e.g. on two adjacent switchgears).
Although the PD level is also measured and output on both sensors during a
comparative measurement like this, this only plays a minor role in localising the weak
point. The propagation time of the pulse from the weak point to the sensor (the so-called
“time of flight”) provides significantly better insights in this case. This provides insight
into which of the two sensors is closer to the weak point.
Proceed as follows to perform a TEV comparative measurement:
1. Connect the TEV-C900-PD to the socket
.
2. Hold the front ends of the PD Scan and the TEV-C900-PD on the two metal
surfaces for comparison.
3. Start the
TEV LOC
operating mode.
Purpose
Procedure
