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Gas discharge tubes


The Gaz Discharge Tube (or GDT) are passive components made of two or three electrodes in an enclosure filled with a (non-radioactive) rare gas at a controlled pressure. The enclosure is a ceramic tube with its ends closed off by metal caps that also serve as electrodes. Their main use is to protect telecommunications lines, but other uses are possible.

The main electrical characteristics defining a gas discharge tube are:

  • DC sparkover voltage (Volts)
  • Impulse sparkover voltage (Volts)
  • Discharge current capacity (kA)
  • Insulation resistance (Gohms)
  • Capacitance (pF)

CITEL gas discharge tubes are available in several mechanical configurations to adapt to the desired set-up:

  • Bare version for mounting adapted support
  • “S” version wire output (diameter 0.8 or 1 mm) for mounting on printed circuit
  • “SMD” version for surface mounting, with optional “SQ” version (anti-roll square electrode)
  • Specific versions: output by cable or rod

CITEL proposes a full line of gas discharge tubes to meet most configuration needs and specifications found on the market:

  • 2- and 3-electrode gas discharge tubes
  • Sparkover voltages from 75 to 3000 V
  • Discharge capacities from 5 to 150 kA (8/20µs)
  • Optional external short-circuit device
  • Installation on support, on printed circuit, or surface-mounted devices.


2-electrode 3-electrode GSG
CA8BB  – BF P100
BA  – BE
BB  –  –