Voltage and Current

The DTK Voltage and Current measurement tests the quality of the electrical contact between the overhead wire and the pantograph.

Variables Captured:

  • Current drawn (by each contact strip or overall)
  • Reverse (braking regeneration) current (through each contact strip or overall)
  • Voltage
  • Position on the route (GPS coordinates and route)
  • Speed

A voltage and current measurement can be combined with all other measurement types.


The voltage and current measurement detects locations at which electrical contact is insufficient, particularly where electric arcs have occurred. This prevents further damage to the overhead wire and the contact strip and prolongs their life.

The measurement determines whether the front and rear contact strip slide positively along the wire and draw current uniformly or whether the current is distributed unevenly between the front and rear contact strip, so causing the wear of the strips to be uneven.

Together with thermal imaging, this measurement provides information about the quality of the power-collecting system.


The DTK evaluation software offers various possibilities for evaluation. For example, the following factors can be determined:

  • Where voltage fluctuations and voltage peaks occur along the route,
  • Whether the current is being drawn equally by the two contact strips,
  • On which route sections the current drawn by either of the two contact strips exceeds a freely specifiable threshold, e.g. 1000 A.

The DTK evaluation software displays the current flowing through the contact strip in a diagram. Depending on the measurement system used, the current is displayed either as overall current or current per contact strip. The voltage diagram shows the voltage at the contact point between the contact strip and the overhead wire.

Measurement system images