... by high temperature resistance, good thermal stability, free selection of heating temperature, and no change in radioactivity for long terms ... : ≤50ppm, ≤10ppm, ≤5ppm, ≤1ppm Applications: It serves as material of infrared heating for heaters, micro-wave oven, electrical baking over ... length should not be over two times of the circumference of the tube. The length of the nick should not be over 12 ...