gdzhxc.com 2021-11-01 294
1. Excessive current used. Tungsten poles are used for a long time under high current conditions. When the temperature reaches the recrystallization temperature of tungsten grains (1600°C), the tungsten grains will become round and thick, and the tungsten poles will become brittle.
1. For long-term use, the current should be used near the allowable current of the tungsten needle.