49
Capacitance and Dissipation Factor Measurement
Figure 5-11 shows the DF of new and used oil, dependent on the temperature.
With higher temperatures, the viscosity of the oil decreases so the particles, ions
and electrons can move easier and faster. Thus the DF increases with
temperature [2.3].
Figure 5-11 DF of new and aged oil, dependent on temperature
Dissipation Factor: Dependency of the temperature
1 = new oil
2, 3 and 4 = used oil
0
/
00
tan δ
10
4
10
3
10
2
10
1
1
-30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 °C
Oil temperature
1
2
3
4