1.Production process is different:
External wiring: The internal resistance wire is soldered to the extraction rod, and then connected to the high temperature lead.
Inner lead: The high temperature lead is directly drawn from the inside of the tube by soldering with the resistance wire.
2.High temperature lead material is different:
External wiring: Since the high-temperature lead is welded to the lead-out bar at the outside, the temperature of the soldering portion is not too high at this time, and the high-temperature lead of the external wiring generally has a temperature resistance of 200 degrees.
Inner lead: Since the high-temperature lead of the inner lead structure is directly soldered from the inside and the inside of the tube, the high-temperature lead of the structure has a temperature resistance of at least 800 degrees, and a pure nickel wire is generally used, so the cost is also Very high.
3.Leakage is different:
From the point of view of leakage, the inner leads are safer.
4.Productivity
The production efficiency of the inner lead is far less than the external wiring. When the inner lead is soldered to the lead wire and the resistance wire, the process is difficult, so the lead of the inner lead should not be too long.
