scope:

This Recommendation deals with: hot cathode tubes and valves, gasfilled rectifier tubes and valves, thyratrons except for those used for pulse modulation, cold cathode tubes, voltage stabilizing tubes, excluding corona stabilizers, trigger tubes. This Recommendation is based on current practice of the measurement of gasfilled tubes and valves. It should not be regarded as a Recommendation in the sense of a standard, because a more detailed description of the methods of measurement is needed if measuring results on the basis of these principles have to be comparable with indefinite tolerances.