Cold Cathode Gauge Contamination: When Should the Anode Be Cleaned or Replaced?
A cold cathode gauge can run reliably for a long time and then start behaving differently. It may take longer than usual to ignite, the reading may become unstable, or the gauge may stop igniting altogether. There are several possible reasons for these problems. One of the first things worth checking is contamination inside the gauge. This is particularly relevant on vacuum equipment where the gauge is exposed to process gases, coating materials, dust, or particles. Over time, deposits can build up on the internal parts and interfere with the discharge used for pressure measurement. That does not always mean the complete gauge needs to be replaced. If the problem is related to deposits on the anode, cleaning may be worth trying first. If the anode is badly contaminated, corroded, or physically damaged, replacement may make more sense. 1. How Can Contamination Affect Gauge Ignition? A cold cathode gauge needs an electrical discharge to operate. The elec...